This study examined the cognitive, behavioral, and personality profiles of male monozygotic triplets who were discordant for sexual orientation. One brother was homosexual (HM) while the other two were heterosexual (HT1 and HT2). The triplets participated in a battery of tests measuring cognitive abilities, personality traits, speech characteristics, and physical traits. The study aimed to determine if HM's profile would differ from his heterosexual brothers, as predicted by theories that biological factors like prenatal hormones influence sexual orientation and related traits. Examining monozygotic triplets discordant for sexual orientation provided a unique opportunity to study potential biological influences while controlling for genetic factors.
A neuropsychologic profile of homosexuasl and heterosexualsTeresa Levy
This article examines differences in neuropsychological profiles between homosexual and heterosexual men and women. It discusses previous research finding some cognitive differences between gay men and heterosexual men on measures of sex differences. The article also reviews theories that sexual orientation develops from sex-atypical patterns of brain development influenced by prenatal sex hormones, with high androgen exposure during development masculinizing neural substrates related to sexual orientation and cognition.
The document discusses the biological approach to gender development. It describes how biological factors like genes, hormones and brain differences influence whether a fetus develops as male or female. During development, testosterone exposure affects the formation of sex organs and later impacts behaviors by changing the brain. Studies on animals, intersex individuals and hormone correlations in humans provide some evidence linking biology to gendered behaviors, though methods have limitations. The complexity of influences on gender is exemplified by cases like Caster Semenya.
A neuropsychologic profile of homo and heteroTeresa Levy
This article examines differences in neuropsychological profiles between homosexual and heterosexual men and women. It discusses previous research finding some cognitive differences between gay men and heterosexual men on measures of sex differences. The article presents the theory that prenatal sex hormones influence both sexual orientation and sexually dimorphic cognitive abilities by masculinizing or feminizing neural substrates in the brain during development. Studies of prenatal hormone manipulations in animals support this theory.
The document discusses biological influences on gender development from conception through adulthood. It explains that the presence or absence of the SRY gene during early fetal development determines whether sex organs develop along male or female lines. During critical prenatal and early childhood periods, males are exposed to higher levels of testosterone than females, which influences brain development and later gendered behaviors. While hormones and genes influence gender development, the complexity of factors involved is demonstrated by cases like Caster Semenya that challenge simple biological definitions of gender.
Ch 2 genetics & evolutionary roots of behaviorMeghan Fraley
This document provides an overview of genetics and evolutionary psychology. It discusses key concepts such as:
1. Genes and heredity, including DNA, chromosomes, genetic transmission, and genetic influences on behavior.
2. Natural selection and evolution, including evolutionary causes of behavior and criticisms of evolutionary psychology.
3. The genetics and evolution of behavior, including heritability estimates, twin studies, and how evolutionary psychologists study the impact of genetics on traits and behaviors.
It explores topics like intelligence, sexuality, parenting, and more from an evolutionary perspective. The document aims to explain genetic and evolutionary roots and influences on human behavior.
Part 1 of "Science & Sexuality." You don't believe that "Adam and Eve" story, do you? Did Eve come from Adam? Or did Adam come from Eve? This is a physiologist's refutation of the biblical binary sexual system. Click on the next 9 slideshows in numerical order for the rest of this scientific update on human sexuality.
The biological approach states that gender development is determined by genes and hormones. In the first 6-8 weeks of development, a fetus will develop either male or female sex organs depending on the presence or absence of the SRY gene. For males, the SRY gene causes development of testes which produce testosterone, triggering male external organ development. Females develop in the absence of male hormones. Later hormone exposure during development and puberty further influence secondary sex characteristics and behaviors through average hormonal differences between males and females. However, social learning and social norms also influence behaviors, and determinism is limited as seen in conditions like androgen insensitivity syndrome.
Biological differences between the sexes - Βιολογικές διαφορές των φύλων Dafnitsa
Πρόγραμμα Comenius με θέμα "Gender Role Inequalities"
Ενότητα: "Βιολογικές διαφορές των φύλων"
Comenius project: " Gender Role Inequalities"
Topic: "The biological differences between the sexes"
A neuropsychologic profile of homosexuasl and heterosexualsTeresa Levy
This article examines differences in neuropsychological profiles between homosexual and heterosexual men and women. It discusses previous research finding some cognitive differences between gay men and heterosexual men on measures of sex differences. The article also reviews theories that sexual orientation develops from sex-atypical patterns of brain development influenced by prenatal sex hormones, with high androgen exposure during development masculinizing neural substrates related to sexual orientation and cognition.
The document discusses the biological approach to gender development. It describes how biological factors like genes, hormones and brain differences influence whether a fetus develops as male or female. During development, testosterone exposure affects the formation of sex organs and later impacts behaviors by changing the brain. Studies on animals, intersex individuals and hormone correlations in humans provide some evidence linking biology to gendered behaviors, though methods have limitations. The complexity of influences on gender is exemplified by cases like Caster Semenya.
A neuropsychologic profile of homo and heteroTeresa Levy
This article examines differences in neuropsychological profiles between homosexual and heterosexual men and women. It discusses previous research finding some cognitive differences between gay men and heterosexual men on measures of sex differences. The article presents the theory that prenatal sex hormones influence both sexual orientation and sexually dimorphic cognitive abilities by masculinizing or feminizing neural substrates in the brain during development. Studies of prenatal hormone manipulations in animals support this theory.
The document discusses biological influences on gender development from conception through adulthood. It explains that the presence or absence of the SRY gene during early fetal development determines whether sex organs develop along male or female lines. During critical prenatal and early childhood periods, males are exposed to higher levels of testosterone than females, which influences brain development and later gendered behaviors. While hormones and genes influence gender development, the complexity of factors involved is demonstrated by cases like Caster Semenya that challenge simple biological definitions of gender.
Ch 2 genetics & evolutionary roots of behaviorMeghan Fraley
This document provides an overview of genetics and evolutionary psychology. It discusses key concepts such as:
1. Genes and heredity, including DNA, chromosomes, genetic transmission, and genetic influences on behavior.
2. Natural selection and evolution, including evolutionary causes of behavior and criticisms of evolutionary psychology.
3. The genetics and evolution of behavior, including heritability estimates, twin studies, and how evolutionary psychologists study the impact of genetics on traits and behaviors.
It explores topics like intelligence, sexuality, parenting, and more from an evolutionary perspective. The document aims to explain genetic and evolutionary roots and influences on human behavior.
Part 1 of "Science & Sexuality." You don't believe that "Adam and Eve" story, do you? Did Eve come from Adam? Or did Adam come from Eve? This is a physiologist's refutation of the biblical binary sexual system. Click on the next 9 slideshows in numerical order for the rest of this scientific update on human sexuality.
The biological approach states that gender development is determined by genes and hormones. In the first 6-8 weeks of development, a fetus will develop either male or female sex organs depending on the presence or absence of the SRY gene. For males, the SRY gene causes development of testes which produce testosterone, triggering male external organ development. Females develop in the absence of male hormones. Later hormone exposure during development and puberty further influence secondary sex characteristics and behaviors through average hormonal differences between males and females. However, social learning and social norms also influence behaviors, and determinism is limited as seen in conditions like androgen insensitivity syndrome.
Biological differences between the sexes - Βιολογικές διαφορές των φύλων Dafnitsa
Πρόγραμμα Comenius με θέμα "Gender Role Inequalities"
Ενότητα: "Βιολογικές διαφορές των φύλων"
Comenius project: " Gender Role Inequalities"
Topic: "The biological differences between the sexes"
The document discusses several key physical and psychological differences between men and women. It notes that men and women process and perceive information differently due to differences in brain structure and wiring. Some of the main differences highlighted include: men having thicker retinas tuned to movement detection while women have thinner retinas tuned to color and texture; male infants showing a preference for moving objects while female infants prefer faces; and males tending to use physical aggression while females favor verbal aggression. The document argues these differences evolved to support traditional gender roles in survival and childrearing.
The document discusses the concept of biological sex as a spectrum rather than a binary, citing evidence of individuals who are intersex - with sexual characteristics that are not exclusively male or female. It argues that there are at least five sexes when considering intersex conditions like hermaphroditism. However, Western culture insists on recognizing only two sexes, often surgically altering intersex infants to fit into male or female categories.
1. Gender identity is usually consistent with chromosomal sex and anatomical development, though biological and environmental factors interact in complex ways. Hormones during prenatal development influence brain morphology and later behavior.
2. Sexual differentiation begins with the SRY gene on the Y chromosome initiating testes development in males through hormones like testosterone and MIS. Errors can result in intersex conditions.
3. Children begin identifying their own gender between 18-36 months, and societies socialize "gender appropriate" roles and behaviors from a young age that influence identity development. However, biology and experience interact throughout life.
This document outlines exam questions related to gender development from 2010 to 2015. It focuses on assessing various theories and approaches to explaining gender, including:
- The biosocial approach and influences of social factors (2010)
- Kohlberg's theory of gender development (2011, 2013)
- Explanations for psychological androgyny (2011)
- Cross-cultural studies of gender roles (2011)
- Research into social influences on gender (2012, 2015)
- Gender schema theory (2012, 2014)
- The biosocial approach and social influences on gender (2013, 2015)
Homosexuality may be explained by epigenetics according to this hypothesis. Epigenetic marks originating in embryonic stem cells regulate fetal androgen sensitivity and act as a buffer, affecting some sexual traits. These sexually-antagonistic epigenetic marks can be produced at birth and escaped erasure between generations, contributing to mismatches between genetic sex and displayed traits in offspring of the opposite sex. Specifically, homosexuality may occur when a stronger-than-average sexually-antagonistic epigenetic mark influencing sexual preference is transmitted to an opposite-gender offspring paired with a weaker sex-specific epigenetic mark. Further research using advances in stem cell technology and epigenetic analysis may provide additional insights into this epigenetic explanation for sexual
This document discusses human sexuality from biological, psychosocial, and behavioral perspectives. It covers topics like the biological basis of sexuality including genetic and hormonal factors, gender identity development, sexual response patterns, and relationships. Key points include that genetics determine biological sex, puberty involves sexual maturation, there are four stages of sexual response, and unhealthy relationships can involve abusive or controlling behaviors.
Sex is biologically determined by X and Y chromosomes, which trigger development of either male or female internal reproductive systems before birth. Hormones like testosterone and estrogen then influence further physical sex differentiation and sexual maturation. Studies have found correlations between higher levels of testosterone and more masculine behaviors in both males and females, such as increased aggression and preference for stereotypically male toys. Sex chromosome abnormalities can also influence physical and behavioral traits, like Klinefelter syndrome causing feminine characteristics in XY males or Turner syndrome resulting in short stature and infertility in XO females.
A Look at Theories on Prenatal Causes of HomosexualityPearce P
This presentation was made for a writing class with a focus on gender and sexuality. It is based off an article by Richard C. Friedman and Jennifer I. Downey. It looks at homosexuality theories from a biological basis.
A Look at Theories on Prenatal Causes of HomosexualityPearce P
This presentation was made for a writing class with a focus on gender and sexuality. It is based off an article by Richard C. Friedman and Jennifer I. Downey. It looks at homosexuality theories from a biological basis.
This document discusses intersex conditions, which involve atypical development of physical sex characteristics. It notes that intersex conditions have been attributed to over 70 chromosomal and hormonal variations. Historically, intersex individuals were referred to as "hermaphrodites," but the term is now considered stigmatizing. The standard medical protocol has been to surgically assign sex and modify genitals of intersex infants, but this approach has increasingly come under criticism for lack of consent, risk of harm, and impact on identity development. Intersex advocates argue for delaying medically unnecessary surgeries and recognizing intersex as a natural variation.
This document provides an overview of key topics related to human sexuality and gender, including:
1) Physical differences between males and females such as primary and secondary sex characteristics.
2) The concepts of gender, gender roles, and gender identity as distinct from biological sex.
3) Theories about the influence of biology and learning on gender development and acquisition of gender roles.
4) Landmark studies that have contributed to understanding of human sexual behavior, orientations, and dysfunctions.
This document discusses intersex lives and identities. It begins by defining intersex as those who are not clearly male or female, and notes that as many as 4% of people are intersex. It discusses how sex is determined by chromosomes, hormones, gonads and genitals, and notes there is a spectrum rather than a strict binary. The document challenges the idea of a gender binary and the notion that gender identity is solely socially constructed. It discusses how prenatal hormones influence brain development and later behaviors and identities, as seen in cases like David Reimer, who was raised as a girl but identified as a boy.
sexuality, sexual orientation, masturbation, autoerotic stimulation to partnered sex; intercourse, oral sex, Gender identity, CULTURAL FACTORS IN SEXUAL ORIENTATION & GENDER IDENTITY, Sexology,Paraphilias,types of sexual behavior deviation
The document discusses the gay and lesbian community. It notes that sexual orientation involves attraction to the same sex. Being gay or lesbian spans all socioeconomic classes and identities. The community has unique needs around security, safety, self-esteem, and identity. Services are underutilized due to fear of judgment. Education often relies on anonymous internet sources due to school difficulties. Workplace discrimination is common. As acceptance has grown, the community has developed businesses and media representation, helping foster pride and identity. Groups provide support for safety, security, and addressing issues like self-esteem.
This document contains references to numerous figures related to circulatory and cardiovascular systems. It discusses the evolution of circulatory systems from simple diffusion in simple organisms to more complex systems using hearts and blood vessels in vertebrates. Key aspects covered include the structure and function of the heart, blood vessels (arteries, veins, capillaries) and blood. It also discusses electrical conduction, hemoglobin, and factors that affect cardiovascular health.
The document discusses how globalization and technology are changing the nature of jobs and the skills needed to succeed. It emphasizes the importance of continuous learning and adapting to have career longevity. It also stresses having a positive attitude and being willing to learn new skills to take advantage of opportunities rather than being threatened by changes.
Applied Learning in Virtual Worlds: Loyalist College Border SimulationKen Hudson
Loyalist College in Second Life used virtual simulations to provide applied training strategies for its students. Trainees spent 4 hours in training and 12 hours practicing skills in a Second Life simulation of the Canadian border crossing process at the Thousand Islands, which allowed them to experience identification checks, vehicle searches, and travel document reviews in an immersive virtual environment. Students reported that the simulation felt more realistic than traditional role plays and improved their performance by 28%, as they were able to learn from watching classmates and experience the border crossing process as if they were truly there.
This article discusses the history of the biological argument for gay identity and its relationship to the modern gay rights movement. It covers:
1) How Karl Heinrich Ulrichs first proposed in the 1860s that homosexuality was an innate "third sex", laying the basis for subsequent biological research and arguments for gay civil rights.
2) How Magnus Hirschfeld and his early 20th century research institute promoted the idea that homosexuality had biological or hormonal causes, gaining some scientific support from early endocrinology experiments.
3) How the German Social Democratic Party initially supported Hirschfeld's biological arguments as a basis for tolerance, though their views on homosexuality were mixed and based more on women
My Second Life didn't turn out the way I thought it would: Managing expectati...Ken Hudson
This document summarizes Ken Hudson's presentation on managing expectations for teaching and learning in virtual worlds. Some key points from virtual worlds include the sense of self, the death of distance, and the power of presence. Studies show that behaviors in virtual worlds can transfer to real life. Loyalist College piloted virtual world simulations for the Canadian Border Services Agency that led to improved grades and testing success compared to traditional teaching methods. Other organizations are also using virtual worlds for training purposes.
This document contains diagrams and figures related to human reproductive anatomy and physiology. It includes figures showing the male and female reproductive systems, testosterone concentration and sperm production, the ovarian cycle, menstrual cycle, and regulation of the menstrual cycle.
The document discusses several key physical and psychological differences between men and women. It notes that men and women process and perceive information differently due to differences in brain structure and wiring. Some of the main differences highlighted include: men having thicker retinas tuned to movement detection while women have thinner retinas tuned to color and texture; male infants showing a preference for moving objects while female infants prefer faces; and males tending to use physical aggression while females favor verbal aggression. The document argues these differences evolved to support traditional gender roles in survival and childrearing.
The document discusses the concept of biological sex as a spectrum rather than a binary, citing evidence of individuals who are intersex - with sexual characteristics that are not exclusively male or female. It argues that there are at least five sexes when considering intersex conditions like hermaphroditism. However, Western culture insists on recognizing only two sexes, often surgically altering intersex infants to fit into male or female categories.
1. Gender identity is usually consistent with chromosomal sex and anatomical development, though biological and environmental factors interact in complex ways. Hormones during prenatal development influence brain morphology and later behavior.
2. Sexual differentiation begins with the SRY gene on the Y chromosome initiating testes development in males through hormones like testosterone and MIS. Errors can result in intersex conditions.
3. Children begin identifying their own gender between 18-36 months, and societies socialize "gender appropriate" roles and behaviors from a young age that influence identity development. However, biology and experience interact throughout life.
This document outlines exam questions related to gender development from 2010 to 2015. It focuses on assessing various theories and approaches to explaining gender, including:
- The biosocial approach and influences of social factors (2010)
- Kohlberg's theory of gender development (2011, 2013)
- Explanations for psychological androgyny (2011)
- Cross-cultural studies of gender roles (2011)
- Research into social influences on gender (2012, 2015)
- Gender schema theory (2012, 2014)
- The biosocial approach and social influences on gender (2013, 2015)
Homosexuality may be explained by epigenetics according to this hypothesis. Epigenetic marks originating in embryonic stem cells regulate fetal androgen sensitivity and act as a buffer, affecting some sexual traits. These sexually-antagonistic epigenetic marks can be produced at birth and escaped erasure between generations, contributing to mismatches between genetic sex and displayed traits in offspring of the opposite sex. Specifically, homosexuality may occur when a stronger-than-average sexually-antagonistic epigenetic mark influencing sexual preference is transmitted to an opposite-gender offspring paired with a weaker sex-specific epigenetic mark. Further research using advances in stem cell technology and epigenetic analysis may provide additional insights into this epigenetic explanation for sexual
This document discusses human sexuality from biological, psychosocial, and behavioral perspectives. It covers topics like the biological basis of sexuality including genetic and hormonal factors, gender identity development, sexual response patterns, and relationships. Key points include that genetics determine biological sex, puberty involves sexual maturation, there are four stages of sexual response, and unhealthy relationships can involve abusive or controlling behaviors.
Sex is biologically determined by X and Y chromosomes, which trigger development of either male or female internal reproductive systems before birth. Hormones like testosterone and estrogen then influence further physical sex differentiation and sexual maturation. Studies have found correlations between higher levels of testosterone and more masculine behaviors in both males and females, such as increased aggression and preference for stereotypically male toys. Sex chromosome abnormalities can also influence physical and behavioral traits, like Klinefelter syndrome causing feminine characteristics in XY males or Turner syndrome resulting in short stature and infertility in XO females.
A Look at Theories on Prenatal Causes of HomosexualityPearce P
This presentation was made for a writing class with a focus on gender and sexuality. It is based off an article by Richard C. Friedman and Jennifer I. Downey. It looks at homosexuality theories from a biological basis.
A Look at Theories on Prenatal Causes of HomosexualityPearce P
This presentation was made for a writing class with a focus on gender and sexuality. It is based off an article by Richard C. Friedman and Jennifer I. Downey. It looks at homosexuality theories from a biological basis.
This document discusses intersex conditions, which involve atypical development of physical sex characteristics. It notes that intersex conditions have been attributed to over 70 chromosomal and hormonal variations. Historically, intersex individuals were referred to as "hermaphrodites," but the term is now considered stigmatizing. The standard medical protocol has been to surgically assign sex and modify genitals of intersex infants, but this approach has increasingly come under criticism for lack of consent, risk of harm, and impact on identity development. Intersex advocates argue for delaying medically unnecessary surgeries and recognizing intersex as a natural variation.
This document provides an overview of key topics related to human sexuality and gender, including:
1) Physical differences between males and females such as primary and secondary sex characteristics.
2) The concepts of gender, gender roles, and gender identity as distinct from biological sex.
3) Theories about the influence of biology and learning on gender development and acquisition of gender roles.
4) Landmark studies that have contributed to understanding of human sexual behavior, orientations, and dysfunctions.
This document discusses intersex lives and identities. It begins by defining intersex as those who are not clearly male or female, and notes that as many as 4% of people are intersex. It discusses how sex is determined by chromosomes, hormones, gonads and genitals, and notes there is a spectrum rather than a strict binary. The document challenges the idea of a gender binary and the notion that gender identity is solely socially constructed. It discusses how prenatal hormones influence brain development and later behaviors and identities, as seen in cases like David Reimer, who was raised as a girl but identified as a boy.
sexuality, sexual orientation, masturbation, autoerotic stimulation to partnered sex; intercourse, oral sex, Gender identity, CULTURAL FACTORS IN SEXUAL ORIENTATION & GENDER IDENTITY, Sexology,Paraphilias,types of sexual behavior deviation
The document discusses the gay and lesbian community. It notes that sexual orientation involves attraction to the same sex. Being gay or lesbian spans all socioeconomic classes and identities. The community has unique needs around security, safety, self-esteem, and identity. Services are underutilized due to fear of judgment. Education often relies on anonymous internet sources due to school difficulties. Workplace discrimination is common. As acceptance has grown, the community has developed businesses and media representation, helping foster pride and identity. Groups provide support for safety, security, and addressing issues like self-esteem.
This document contains references to numerous figures related to circulatory and cardiovascular systems. It discusses the evolution of circulatory systems from simple diffusion in simple organisms to more complex systems using hearts and blood vessels in vertebrates. Key aspects covered include the structure and function of the heart, blood vessels (arteries, veins, capillaries) and blood. It also discusses electrical conduction, hemoglobin, and factors that affect cardiovascular health.
The document discusses how globalization and technology are changing the nature of jobs and the skills needed to succeed. It emphasizes the importance of continuous learning and adapting to have career longevity. It also stresses having a positive attitude and being willing to learn new skills to take advantage of opportunities rather than being threatened by changes.
Applied Learning in Virtual Worlds: Loyalist College Border SimulationKen Hudson
Loyalist College in Second Life used virtual simulations to provide applied training strategies for its students. Trainees spent 4 hours in training and 12 hours practicing skills in a Second Life simulation of the Canadian border crossing process at the Thousand Islands, which allowed them to experience identification checks, vehicle searches, and travel document reviews in an immersive virtual environment. Students reported that the simulation felt more realistic than traditional role plays and improved their performance by 28%, as they were able to learn from watching classmates and experience the border crossing process as if they were truly there.
This article discusses the history of the biological argument for gay identity and its relationship to the modern gay rights movement. It covers:
1) How Karl Heinrich Ulrichs first proposed in the 1860s that homosexuality was an innate "third sex", laying the basis for subsequent biological research and arguments for gay civil rights.
2) How Magnus Hirschfeld and his early 20th century research institute promoted the idea that homosexuality had biological or hormonal causes, gaining some scientific support from early endocrinology experiments.
3) How the German Social Democratic Party initially supported Hirschfeld's biological arguments as a basis for tolerance, though their views on homosexuality were mixed and based more on women
My Second Life didn't turn out the way I thought it would: Managing expectati...Ken Hudson
This document summarizes Ken Hudson's presentation on managing expectations for teaching and learning in virtual worlds. Some key points from virtual worlds include the sense of self, the death of distance, and the power of presence. Studies show that behaviors in virtual worlds can transfer to real life. Loyalist College piloted virtual world simulations for the Canadian Border Services Agency that led to improved grades and testing success compared to traditional teaching methods. Other organizations are also using virtual worlds for training purposes.
This document contains diagrams and figures related to human reproductive anatomy and physiology. It includes figures showing the male and female reproductive systems, testosterone concentration and sperm production, the ovarian cycle, menstrual cycle, and regulation of the menstrual cycle.
The document discusses application servers used by Utah government agencies and provides recommendations for standardizing their use. It finds that many different application servers are currently used. It recommends reducing this number by migrating most to use GlassFish as the standard Java EE5 application server platform and integrating it with other state services. It also recommends minimizing new development on older platforms and specifying approved IDEs to use with GlassFish.
Stichting Doen seeks to scale their social impact through labour (re)integration projects. A social safari team conducted research and interventions with Doen to develop a vision. They propose Doen take an active role in becoming the most inspiring foundation by launching an annual incentive-based competition called "The Doen Challenge" to spur social innovation. Doen would also adopt a social media strategy, create a knowledge sharing hub called "Doen Labs", and empower community involvement to spread their mission.
This document outlines an 11-step process for setting up an effective Adwords campaign including: 1) creating an account and campaign, 2) setting location/language/device targets, 3) creating ad groups with themes and languages, 4) choosing keywords based on site/competition/inspiration, 5) selecting keyword match types, 6) adding negative keywords, 7) writing relevant ads with calls to action and optimized landing pages, 8) measuring performance and optimizing, 9) setting up conversion tracking, 10) linking Adwords and Analytics accounts, and 11) providing contact information for questions.
Este documento descreve os serviços de mobilidade corporativa fornecidos pela Navita, incluindo distribuição de dispositivos BlackBerry, gerenciamento de infraestrutura móvel, suporte técnico e treinamento para clientes corporativos. A Navita oferece soluções para aprovação de compras e propostas, relatórios gerenciais e mobilização de processos de ERP, CRM e intranet no BlackBerry.
From MySpace to MySociety to MyDemocracyKennisland
The medialandscape is changing. In this presentation the emerging role of the civil society media will be outlined against the changing medialandscape.
This blog post discusses some free audio and video learning resources that were recently discovered online, including Learner.org which offers many free video tutorials on topics like algebra and French, and MediaSite.com which has over 7,500 free presentations and lectures. It also mentions Voices in the Dark which offers free MP3 audiobooks and provides links to these resources.
Modern web applications embrace personalization in order to provide a unique customer experience. Recommendation engines, in general, and Collaborative Filtering, in particular, are essential techniques for delivering state-of-the-art personalization effects on a web site.
These slides are based on a presentation that I gave to New England's Java User Group (NEJUG) in 2009; in that respect, they are quite old. Nevertheless, the content is about the fundamental concepts of these techniques and the fundamentals never go out of fashion.
The code references are from the project Yooreeka. The Yooreeka project started with the code of the book "Algorithms of the Intelligent Web " (Manning 2009). You can find the Yooreeka 2.0 API (Javadoc) at http://www.marmanis.com/static/javadoc/index.html
Homosexuality, birth order, and evolutionTeresa Levy
This article proposes that homosexuality can be explained by a polygenetic trait influenced by multiple genes. During development, these genes shift male brain development in a more feminine direction. While single alleles may produce homosexuality, carriers of these alleles who are heterosexual tend to be better fathers and more attractive mates. This balanced polymorphism allows alleles that contribute to homosexuality to survive by offsetting their negative reproductive impacts through positively impacting heterosexual carriers. A similar effect is proposed to exist for genes that could produce lesbianism in females.
Biological in uences onhomosexualityCurrent Ž ndings and .docxhartrobert670
This document summarizes research on potential biological influences on homosexuality. It discusses both structural and functional brain studies that have found differences between heterosexual and homosexual individuals. The structural studies identified sexually dimorphic brain regions in areas like the hypothalamus and found some differences according to sexual orientation. However, results were inconsistent. Functional studies using EEG found differences in brain activity patterns between heterosexual and homosexual males during cognitive tasks. Overall, the research is still in early stages with inconsistent findings, and more work is needed.
Finger length ratios in female monozygotic twinsTeresa Levy
This study examines finger length ratios in female monozygotic twins who are discordant for sexual orientation. Previous research has found that lesbian women tend to have lower finger length ratios, suggesting higher prenatal androgen exposure. The study aims to determine if differences in prenatal environment contribute to differences in sexual orientation for these twins by examining their finger length ratios. If finger length ratios differ between twins discordant for sexual orientation, it would provide evidence that prenatal environment, not just genetics, impacts development of sexual orientation.
Homosexuality, birth order, and evolution (2)Teresa Levy
This journal article proposes that homosexuality can be explained by a polygenetic trait influenced by multiple genes. During development, these genes shift male brain development in a more feminine direction. While single alleles may produce homosexuality, carriers of these alleles who are heterosexual tend to be better fathers and more attractive mates. There is a balanced polymorphism where the feminizing effects in heterosexuals offsets the reproductive disadvantages of these alleles contributing to homosexuality. The birth order effect on homosexuality may be a byproduct of a mechanism that shifts later-born sons' personalities more femininely, reducing competition with brothers.
How hormones affect behavioral and neural developmentTeresa Levy
This document provides an introduction to a special issue journal on how gonadal hormones affect behavioral and neural development. It summarizes several studies showing that hormones like testosterone and estrogen influence behaviors in humans and other species. For example, females exposed to high testosterone levels prenatally tend to show more male-typical behaviors. The introduction discusses themes across the special issue articles, such as how hormones have both organizational effects during development and activational effects in adulthood. It also provides background on the range of methods used to study hormone-behavior relationships.
P1 IZOArchives of Sexual Behavior pp744-aseb-460154 Februar.docxgerardkortney
P1: IZO
Archives of Sexual Behavior pp744-aseb-460154 February 3, 2003 12:24 Style file version July 26, 1999
Archives of Sexual Behavior, Vol. 32, No. 2, April 2003, pp. 103–114 ( C! 2003)
Handedness, Sexual Orientation, and Gender-Related
Personality Traits in Men and Women
Richard A. Lippa, Ph.D.1
Received April 19, 2002; revision received October 1, 2002; accepted November 15, 2002
This study assessed large numbers of heterosexual and homosexual men and women on handedness
andgender-relatedpersonality traits. Initialanalysesemployedadichotomousmeasureofhandedness
(right-handed vs. non–right-handed). For men and women combined, homosexual participants had
50% greater odds of being non–right-handed than heterosexual participants, a statistically significant
difference.Homosexualmenhad82%greateroddsofbeingnon–right-handedthanheterosexualmen,
astatisticallysignificantdifference,whereashomosexualwomenhad22%greateroddsofbeingnon–
right-handedthanheterosexualwomen,anonsignificantdifference.Whenparticipantswereclassified
into five graduated categories of handedness, both men and women showed significant homosexual–
heterosexualdifferences inhandednessdistributions.Withingroups,handedness showedanumberof
weak but statistically significant associations with sex-typed occupational preferences, self-ascribed
masculinity, and self-ascribed femininity, but not with instrumentality or expressiveness. Rates of
non–right-handedness were virtually identical for heterosexual men and women, suggesting that sex
differences in handedness may result from higher rates of homosexuality in men.
KEY WORDS: handedness; sexual orientation; sex differences; masculinity; femininity.
INTRODUCTION
Ina recentmeta-analysis,Lalumière,Blanchard,and
Zucker(2000)compiledevidenceonassociationsbetween
handedness and sexual orientation in men and women.
Data from 6,182 homosexual and 14,808 heterosexual
men showed that homosexual men had 34% greater odds
of being non–right-handed than heterosexual men, and
datafrom805homosexualand1,615heterosexualwomen
showed that homosexual women had 91% greater odds of
being non–right-handed than heterosexual women. Both
of these differences were statistically significant. A num-
ber of recent studies have also indicated that gender iden-
titydisorder isassociatedwithnon–right-handedness (see
Green and Young, 2001, and Zucker, Beaulieu, Bradley,
Grimshaw, and Wilcox, 2001, for reviews and new data).
Although there is now considerable evidence for an
association between non–right-handedness and certain
kinds of strong gender-atypicality (e.g., homosexuality,
1Department of Psychology, California State University, Fullerton,
California 92834; e-mail: [email protected]
gender identity disorder), the evidence is weaker for
associations between handedness and other kinds of
gender-related individual differences. Perhaps the best-
documented finding is that there are slightly higher rates
of left-handedness in males than females. In an int.
Write an essay of at least 900 words (3 pages) in which you disc.docxbriankimberly26463
Write an essay of at least 900 words (3 pages) in which you discuss one aspect of our border policy. Use and establish a representative example from
"Hole in the Fence"
,
"Hold the Line"
, or
"What Remains."
Use the techniques from
Writing Analytically
in order to generate your significant details from the text and your interpretation of them. Your approach should be analytical. A successful essay will establish a representative example from the text and examine the significance and implications of the idea/thesis that you are developing while making your thesis evolve. It is important to focus and go deeper on one aspect of example or topic.
Your essay should have the following requirements:
an analytical approach
a representative example from the reading that you are analyzing
an evolving thesis that results from examining complicating evidence
MLA format and citation of sources
Respond to the two drafts assigned to you later when I submit the essay.
I need to follow the peer review process, including instructions for providing feedback to other two drafts.
I'm in USA currently so USA border policy will work.
I think we can use examples from those three podcasts or any other resources.
It is essential to cite and connect the essay.
I can send you the previous work if you want to see it as a reference.
Since we were young, we are engulfed by sex lore. It is still in dialogue, laughter, and confrontation, and everything from driving types to food tastes must be clarified. Sex is so deeply incorporated into our structures, behavior, values, and expectations that it seems inherently familiar to us. The environment has several theories about gender – and these concepts are so prevalent that we take it for granted that they are valid. As analysts, scientists, and historians, though, it is our task not only to discover the facts behind it but also to glance over what seems to be a common cause. Just since gender appears to be expected, and gender values tend to be simple realities, we ought to step back and look at gender from a different viewpoint. To achieve this, we need to interrupt our routines, which is comfortable and to challenge sure of our core convictions. This is not simple because gender is so fundamental to our view of ourselves and the universe that it's hard to reverse and reverse.Look at things in a different light. However, the idea that the analysis of gender is apparent renders it fascinating precisely. Gender appears obviously, it brings the task of uncovering the building mechanism that causes what we have always believed to be expected and unforgivable to explore sex, not as a predetermined object, but as an achievement (Gumperz, 2012).
The mass media and the scholarly study on language and identity demonstrate the implications of not understanding this problem. As a consequence, individual gender bonds enhance and facilitate current convictions to achieve others (Jordan, 2010). Biological variati.
Ans.) Researchers have found much more proof that sexual orientation.pdfanjalitimecenter11
Ans.) Researchers have found much more proof that sexual orientation is to a great extent
controlled by hereditary qualities, not decision. That can undermine a noteworthy contention
against the LBGT people group that claims that these individuals are living \"unnaturally.\"
According to latest research conducted and published in scientific journals the two areas of
human genome - one on the X chromosome and one on chromosome 8.
The relationship amongst science and sexual orientation is a subject of deep research and
analysis. A straightforward and particular determinant for sexual orientation has not been
indisputably illustrated; different studies indicate diverse, notwithstanding clashing positions,
however researchers theorize that a blend of genetics, hormonal and social elements decide
sexual orientation. Biological hypotheses for clarifying the reasons for sexual orientation are
more popular and natural elements may include an intricate interaction of hereditary components
and the early uterine, environment. These variables, which might be identified with the
improvement of a hetero, gay person, promiscuous orientation, incorporate qualities, pre-birth
hormones, and cerebrum structure.
According to a study, every single grown-up twin in Sweden (more than 7,600 twins) found that
same-sex conduct was clarified by both genetic elements and individual-particular natural
sources, (for example, pre-birth environment, involvement with sickness and injury and also peer
bunches and sexual encounters), while impacts of shared-environment factors, for example,
familial environment and social demeanors had a weaker, yet noteworthy impact. Women
demonstrated a factually non-critical pattern to weaker impact of genetic impacts, while men
demonstrated no impact of shared ecological impacts.
Chromosome linkage analysis of sexual orientation has shown the presence of different
contributing hereditary elements all through the genome. In 1993 Dean Hamer and partners
published their finding from a linkage examination of a specimen of 76 homo siblings and their
families. The researcher found that the homo men had more homo male uncles and cousins on
the maternal side of the family than on the fatherly side. Gay siblings who demonstrated this
maternal family were then tried for X chromosome linkage, utilizing twenty-two markers on the
X chromosome to test for comparable alleles. In another discovering, thirty-three of the forty kin
sets tried were found to have comparable alleles in the distal district of Xq28, which was
altogether higher than the normal rates of half for friendly siblings. This was prominently named
the \" homo quality\" in the media, bringing on noteworthy discussion. Sanders et al. in 1998
investigated their comparative study, in which they found that 13% of uncles of homosexual
siblings on the maternal side were homo person, contrasted and 6% on the fatherly side.
Hence, it is concluded that up to some extent homosexuality or sex orient.
Notes from class · Sex VS. Gender· Sex = Biology Gender = S.docxcherishwinsland
Notes from class:
· Sex VS. Gender
· Sex = Biology Gender = Social Construction
· Male = XY chromosomes Female = XX chromosomes
· Masculine/ Androgynous/ Feminine:
· Gender Identity:
· A person's perception of having a particular gender, which may or may not correspond with their birth sex.
· Sexual Orientation:
· Who you are attracted to.
· Heterosexual, Bisexual, Pansexual, A- Sexual, Gay/ Lesbian.
· Corpus Callosum:
· a broad band of nerve fibers joining the two hemispheres of the brain.
Chapter 2
Theoretical Approaches to Gender Development Knowledge Challenge:
When do most children understand that they are male or female and that their sex is not going to change? How does a person develop a standpoint? Which sex has a documented hormonal cycle? A student of mine named Jenna told me that theory bores her because it has nothing to do with “real life.” But the premier social scientist Kurt Lewin disagreed when he insisted, “There is nothing so practical as good theory.” What he meant, and what I tried to explain to Jenna, is that theories are very practical. They help us understand, explain, and predict what happens in our real lives and in the world around us. Theoretical Approaches to Gender A theory is a way to describe, explain, and predict relationships among phenomena. Each of us uses theories to make sense of our lives, to guide our attitudes and actions, and to predict others’ behavior. Although we’re not always aware of the theories we hold, they still shape how we act, how we expect others to act, and how we explain, or make sense of, what we and others say and do. In this sense, theories are very practical. Among the theories that each of us has are ones we use to make sense of men’s and women’s behaviors. For instance, assume that you know Kevin and Carlene, who are 11-year-old identical twins. In many ways, they are alike; yet they also differ. Carlene is more articulate than Kevin, and she tends to think in more integrative ways. Kevin is better at solving analytic problems, especially ones that involve spatial relations. He also has better-developed muscles, although he and Carlene spend equal time playing sports. How you explain the differences between these twins reflects your implicit theory of gender. If put a lot of trust in biology, you might say that different cognitive strengths result from hemispheric specialization in male and female brains. You might also assume that Kevin’s greater muscle development results from testosterone, which boosts musculature, whereas estrogen programs the body to develop less muscle and more fat and soft tissue. Then again, if you believe socialization shapes development, you might explain the twins’ different cognitive skills as the result of what parents reward. Similarly, you might explain the disparity in their muscle development by assuming that Kevin is more encouraged and more rewarded than Carlene for engaging in activities that build muscles. These are only two of .
Hand preference, sexual preference and transsexualismTeresa Levy
This journal article examines the relationship between hand preference, sexual preference, and transsexualism. The authors studied 443 male-to-female and 93 female-to-male transsexuals and found they were more often non-right handed compared to male and female controls. This suggests an altered pattern of cerebral hemispheric organization in transsexuals. Prenatal androgen levels may influence both handedness and psychosexual development. Elevated testosterone in utero could affect brain development and increase non-right handedness.
A neuropsychologic profile of homosexual and heterosexualTeresa Levy
This article summarizes recent studies examining differences in neuropsychological profiles between homosexual and heterosexual men and women. Some studies have found differences in cognitive patterns between gay men and heterosexual men on measures of typical sex differences, but two studies found no effects of sexual orientation. Little is known about differences between lesbians and heterosexual women, as the few published reports found no significant differences. The studies aim to understand the etiology of sexual orientation by examining neurocognitive development in the direction of one's opposite sex. Prenatal hormone theory suggests high concentrations of androgenic hormones during brain development masculinize neural substrates related to sexual orientation and cognition.
Genetic and Environmental Influences on Female SexualOrientaMatthewTennant613
Genetic and Environmental Influences on Female Sexual
Orientation, Childhood Gender Typicality and Adult
Gender Identity
Andrea Burri1,2*, Lynn Cherkas2, Timothy Spector2, Qazi Rahman1*
1 Biological and Experimental Psychology Group, School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom, 2 Department
of Twin Research and Genetic Epidemiology, King’s College London, London, United Kingdom
Abstract
Background: Human sexual orientation is influenced by genetic and non-shared environmental factors as are two
important psychological correlates – childhood gender typicality (CGT) and adult gender identity (AGI). However,
researchers have been unable to resolve the genetic and non-genetic components that contribute to the covariation
between these traits, particularly in women.
Methodology/Principal Findings: Here we performed a multivariate genetic analysis in a large sample of British female
twins (N = 4,426) who completed a questionnaire assessing sexual attraction, CGT and AGI. Univariate genetic models
indicated modest genetic influences on sexual attraction (25%), AGI (11%) and CGT (31%). For the multivariate analyses, a
common pathway model best fitted the data.
Conclusions/Significance: This indicated that a single latent variable influenced by a genetic component and common non-
shared environmental component explained the association between the three traits but there was substantial
measurement error. These findings highlight common developmental factors affecting differences in sexual orientation.
Citation: Burri A, Cherkas L, Spector T, Rahman Q (2011) Genetic and Environmental Influences on Female Sexual Orientation, Childhood Gender Typicality and
Adult Gender Identity. PLoS ONE 6(7): e21982. doi:10.1371/journal.pone.0021982
Editor: Stacey Cherny, University of Hong Kong, Hong Kong
Received March 9, 2011; Accepted June 14, 2011; Published July 7, 2011
Copyright: � 2011 Burri et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: These authors have no support or funding to report.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: [email protected] (AB); [email protected] (QR)
Introduction
Understanding of the origins of sexual orientation can help
narrow competing developmental explanations for behavioral sex
differences in general and is of increasing importance to
researchers concerned with the physical and mental health of
sexual minorities [1,2]. Homosexuality appears to be a stable
sexual phenotype in humans with population-based surveys
suggesting lifetime prevalence of 2–4% in men and 0.5–1.5% in
women when measured as exclusive same-sex ‘‘feelings’’ (e.g.,
homosexual attractions and fantasies) [3,4]. The distribution of the
...
The document discusses whether being gay is something someone is born with or a behavior acquired through environmental influences. It reviews perspectives from both sides of the debate, citing scientific studies that have attempted to study biological factors like genetics, brain structures, and hormone levels, as well as psychosocial factors like childhood experiences and relationships. However, the document concludes that there is no clear evidence that definitively proves either the innate or learned nature of sexual orientation, as different studies have limitations and conflicting results. The issue remains controversial with arguments on both sides.
This study investigated whether the previously observed association between pedophilia and lower IQ scores is influenced by the source of patient referrals. The study analyzed data from 832 male patients referred to a clinic for sexual behavior evaluations. Patients were assigned to groups based on their erotic preferences for children or adults, as assessed by phallometric testing. Results showed lower IQ scores and increased rates of non-right-handedness were associated with pedophilia, regardless of whether patients were referred by lawyers, parole/probation officers, or other sources. This supported the conclusion that the link between pedophilia and cognitive function is real and not due to referral biases. The findings were interpreted as evidence that neurodevelopmental problems may increase
14Gender and SexualitySeverin SchweigerCulturaGetty Imag.docxaulasnilda
14Gender and Sexuality
Severin Schweiger/Cultura/Getty Images
Learning Objectives
After completing this module, you should be able to:
ሁ Outline the biological, social, and cognitive explanations for the emergence of gender identity.
ሁ Form evidence-based arguments on gender differences in development.
ሁ Summarize the developmental imperative of physical activity for boys and girls during childhood.
ሁ Compare and contrast school achievement and learning between boys and girls.
ሁ Describe differences and similarities among heterosexual girls, heterosexual boys, and LGBT
adolescents with regard to romantic relationships and identity formation.
ሁ Discuss the psychological effects of puberty.
ሁ Evaluate ethnic and national differences in sexual activity among adolescents; explain the
consequences of teenage pregnancy.
ሁ Identify different health outcomes of sex during adolescence, including categorizing STIs and the
effects of HIV among infected children worldwide.
Section 14.1The Development of Gender
Prologue
Recent stories have led to renewed discussion about sex and gender in society. Sasha Lax-
ton from Great Britain; Storm Stocker from Toronto, Canada; and Pop from Sweden have all
made headlines as their parents were determined to raise them without regard to gender. The
children’s rooms were painted in neutral colors; hairstyles, Halloween costumes, and cloth-
ing were chosen without perceived regard for gender standards; exposure to toys and other
activities were not limited by what was considered “normal” for a boy or a girl.
As a result, there has been considerable debate among parents, academics, and the media
about the potential detriment—and benefit—if children are not aware of how they are “sup-
posed” to behave. However, these families are also quite outside the mainstream. It takes
tremendous effort to rid a child of messages related to gender, including limiting exposure
to media, avoiding certain store shelves, and restricting access to preschool and other social
activities.
For most children, though, sex and gender are inescapably connected. It is extremely rare for
a child to be born with undifferentiated sex organs. Even so, those children still generally have
either XX or XY genes. Biological sex is therefore not particularly variable. By contrast, regard-
less of biological sex, gender is much more continuous. Some children are drawn quite strongly
to the behaviors and activities of one gender over another, whereas other children engage
freely in more varied activities. This module explores these issues, as well as concerns related
to adolescent sex and romantic relationships and their developmental consequences.
14.1 The Development of Gender
Recall the many different factors involved in the development of the self and the formation
of gender identity (see Module 12). Gender is a key component in the development of the
self. In psychology, gender refers to the meanings societies and ...
This document summarizes current research on mate selection in humans from an evolutionary psychology perspective. It discusses that past research has largely focused on heterosexual relationships and chimpanzee behavior, ignoring factors like same-sex relationships, gender fluidity in females, environmental influences, and the role of male power in shaping mating patterns. The document argues for a more comprehensive, feminist approach to evolutionary psychology that examines diverse species like bonobos and centers females, in order to develop theories that more fully explain human mate selection behaviors.
This document discusses theories of gender identity development. It notes that while biology and heredity play a role, environmental factors are also important. Gender identity generally forms early in childhood through social learning from caregivers. The document examines multiple theories for the development of sexual orientation, such as prenatal hormone exposure, the fraternal birth order effect, and genetic influences. However, none of the theories fully explain gender identity and sexuality remains complex with biological and social influences.
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Bio rhetoric, background beliefs and the bio of homo
Cognitive, behavioral and personality profiles
1. The Cognitive, Behavioral and Personality Profiles of a Male Monozygotic Triplet Set Discordant for
Sexual Orientation
Journal article by Scott L. Hershberger, Nancy L. Segal; Archives of Sexual Behavior, Vol. 33, 2004
The Cognitive, Behavioral, and Personality
Profiles of a Male Monozygotic Triplet Set
Discordant for Sexual Orientation.
by Scott L. Hershberger , Nancy L. Segal
INTRODUCTION
Few would dispute the importance of sexual orientation in persons' lives and, in recognition of this, researchers
have actively sought its origins during the last two decades. Much of this work has focused on how biological
mechanisms influence sexual orientation development, the results of which suggest that genes, brain anatomy,
and prenatal sex hormones influence sexual orientation in men (Hershberger, 2001). Researchers have used
two broad approaches to the biological origins of sexual orientation: neurohormonal and genetic. In one way or
another, all biological approaches to the origins of sexual orientation encompass either one of these views.
Neurohormonal Etiology
A neurohormonal etiology is based on the reasoning that sexual orientation depends on the early sexual
differentiation of hypothalamic brain structures. The differentiation of these brain structures, in turn, depends
on prenatal androgen. Masculinization of brain structures occurs because of relatively high levels of androgens,
whereas feminization of brain structures occurs in the absence of sufficient levels of androgens. These
differences led to the idea that homosexual men and heterosexual women have neural sexual orientation
centers that are similar to each other and different from those of heterosexual men and homosexual women.
The results of two different avenues of investigation strongly support this idea. In the first, studies have been
conducted examining the effects of prenatal patterns of sex steroid secretion on the development of sexually
dimorphic behaviors in nonhuman animals. Animals who have had their prenatal hormonal environments
experimentally altered to mimic the hormonal environment of the opposite sex frequently exhibit postnatal
sexual behaviors characteristic of the opposite sex (see Breedlove, 1994, for a review). For example, male rats
who have experienced prenatal androgen-deficient hormonal environments exhibit lordosis, lack of
aggressiveness, and avoid rough-and-tumble play. Conversely, female rats who have experienced unusually
high levels of androgen exhibit mounting behavior, increased levels of aggression, and avoidance of maternal
rearing behavior.
A second line of neurohormonal research studies humans whose prenatal sex steroid environment has been
atypical because of a physical disorder. The most frequently studied condition arising from an atypical prenatal
hormonal environment has been congenital adrenal hyperplasia (CAH), an inherited, autosomal recessive
disorder of adrenal steroidogenesis. CAH causes excessive production of adrenal androgens; in female
newborns, this results in full or partially masculinized external genitalia, whereas in male newborns, it appears
to have little or no apparent effect. CAH females exhibit unusually high levels of masculine-type behavior,
including "masculine" toy preferences, high rates of masculine gender identity, elevated rates of homosexual
fantasy and behavior, and low marital rates (Meyer-Bahlburg, 2001).
Genetic Etiology
Genetic differences among individuals could also trigger differences in sexual orientation, perhaps by inducing
differences in prenatal androgen levels or sensitivity to androgen. Behavior genetic studies, primarily using
twins, have been the most productive methods of exploring genetic influence on sexual orientation and
behavior. Twin studies generally compare resemblance between monozygotic (MZ) and dizygotic (DZ) twins
(Segal, 2000). To date, there have been nearly a dozen large studies comparing the concordance rates of MZ
and DZ twins for homosexuality. These studies generally converge on the conclusion that sexual orientation is
significantly influenced by genetic factors in men, but less so in women (Hershberger, 2001).
Twin studies are, however, vulnerable to some design problems that could compromise the interpretation of
their results. For example, concordant-dependent ascertainment, in which there is a greater likelihood of MZ
twins concordant for sexual orientation volunteering than those MZ twins who are discordant may occur. There
is also a greater likelihood in general of MZ twins volunteering than DZ twins (Neale, Eaves, & Kendler, 1989).
Moreover, there are at least three problems to which twin studies of sexual orientation are particularly
susceptible. First, the representativeness of the samples are open to question, because many of the studies
obtain participants through homophile publications, which may not have a readership reflective of the general
homosexual population (e.g., Whitam, Diamond, & Martin, 1993). Second, how sexual orientation is defined
affects the magnitude of the computed heritability (e.g., Hershberger, 1997). Third, certain analytic
approaches to estimating heritability require knowledge of the population base rate of homosexual orientation
(e.g., Bailey & Pillard, 1991). Perhaps the strongest studies of genetic influence on sexual orientation use large
population-based strategies for obtaining twins (e.g., twin registries; Kirk, Bailey, & Martin, 2000).
2. Importantly, population-based studies report heritability estimates of sexual orientation significantly lower than
studies that rely on advertising or word of mouth to obtain participants.
Sexual Orientation and Cognitive Ability
Finding that biology plays a significant role in sexual orientation is of considerable consequence for the
emergence of cognitive differences between homosexual and heterosexual men. If a hormonal explanation of
sexual orientation is correct, we would expect the cognitive attributes of male homosexuals to be femininzed,
more closely resembling heterosexual females than heterosexual males. Sex differences should, in this case,
generalize to sexual orientation differences.
The most dramatic sex difference in cognitive ability is found on measures of spatial ability, in particular tests
of mental rotation, with males typically outperforming females (Linn & Petersen, 1985; Voyer, Voyer, &
Bryden, 1995). To a lesser extent, men also perform better on measures of spatial perception, such as the
water-level test, which asks participants to predict the appearance of the water level in containers that are
presented in various orientations. However, negligible sex differences are found on tests of spatial visualization
(e.g., the Block Design subtest of the Wechsler Adult Intelligence Scale), a third type of spatial ability test
(Voyer et al., 1995). Males also tend to outperform women on tests of mathematical reasoning ability (Becker
& Hedges, 1984). In contrast, evidence exists for female superiority on tests of verbal fluency, an example of
which is to name as many words as one can that begin with the letter "F" during a brief period of time
(Halpern, & LaMay, 2000). Females are also found to outperform men on tests requiring rapid visual scanning
and matching, as well as on tests of location memory (Halpern & Crothers, 1997).
Evidence suggests that sex differences in cognitive abilities are prenatal in origin. According to one theory, high
levels of prenatal testosterone slow the development of the left hemisphere in men, resulting in hemispheric
lateralization for many cognitive tasks. In men, language functions are mediated by the left hemisphere,
whereas spatial functions are mediated by the right hemisphere; however, hemispheric lateralization is less
strong in women, as evidenced by the presence of language functions in the right hemisphere (McGlone,
1980). The presence of language functions in the right hemisphere appears to interfere with information
processes in women (thus accounting for their relatively poorer performance), but at the same time improves
their processing of linguistic information. Women can call upon either their right or left hemisphere for
interpreting linguistic information.
If prenatal hormonal effects on CNS development can be used to explain sex differences in cognitive ability,
then they can also be used to explain the origin of differences in cognitive abilities between homosexual and
heterosexual men. For example, Willmott and Brierley (1984) found that although there were no overall IQ
differences between heterosexuals and homosexuals, homosexual males had higher verbal IQs than did
heterosexual males and females. A similar result was obtained by Tuttle and Pillard (1991), who found that
homosexual males had higher vocabulary scores on the Wechsler Adult Intelligence Scale than did heterosexual
males. McCormick and Witelson (1991) found that homosexual males had greater verbal fluency than did
heterosexual males, but neither male group was as fluent as heterosexual females. On a computerized lexical-
decision-making task, heterosexual women and homosexual men performed comparably, and superior, to
heterosexual men (Wegesin, 1998). Rahman, Abrahams, and Wilson (2003) also showed that homosexual men
outperformed heterosexual men on synonym, category, and letter fluency tests.
Studies of spatial abilities show even more consistent results, with several investigators reporting that
heterosexual males outperformed homosexual males and heterosexual females (e.g., Cohen, 2002; Gladue,
Beatty, Larson, & Stratton, 1990; Rahman & Wilson, 2003; Sanders & Ross-Field, 1986; Tuttle & Pillard, 1991;
Wegesin, 1998; Willmott & Brierley, 1984). A number of studies have also found that homosexual men score
higher on the intellectual and openness to change factors (factors B and [Q.sub.1], respectively) of the 16
Personality Factor Questionnaire (16PF), both of which are significantly correlated with general intelligence
measures (see Duckitt & du Toit, 1990).
Other Sexual Orientation Differences
Sexual orientation differences have also been found on gender conformity, somatic measures, and voice and
speech characteristics. The greater recalled gender atypicality of homosexual men is one of the most robust
findings in sexual orientation research (Bailey & Zucker, 1995). If hormones influence the development of sex
dimorphic behavior and sexual orientation, an atypical gender identity would be expected among homosexual
males. Somatic measures show sexual orientation differences consistent with hormonal influences; for
example, homosexual men tend to weigh less than heterosexual men (e.g., Bogaert & Blanchard, 1996).
Somatic differences are also found for the hands: Homosexual men have elevated rates of non-right-
handedness (Lalumiere, Blanchard, & Zucker, 2000) and more dermal ridges on the left hand (Green & Young,
2000). Voice and speech differences between homosexual and heterosexual men are also consistent with sex
differences. For examples, a higher pitch is usually associated with feminine speech (Bachorowski & Owren,
1999); homosexual males are perceived to have higher pitched voices than heterosexual males (Gaudio,
1994).
This Study
The primary purpose of this study was to explore differences between the cognitive ability profiles of
homosexual and heterosexual males. In addition, comparisons were conducted on somatic measures, measures
of voice and speech, and masculinity-femininity, all of which were expected to show male sexual orientation
3. differences.
A unique approach to testing cognitive ability differences between homosexual and heterosexual men
presented itself when the first author was on the faculty of a large, Midwestern university. A set of triplets,
three brothers, who were attending the university, learned of the author's interest in biological influences on
sexual orientation and introduced themselves to him. The brothers were 21 years of age. Even with the
increase in multiple births caused by assisted reproductive technology, MZ triplets are still relatively rare,
representing 1 in 50,000 births (Reynolds, Schieve, Martin, Jeng, & Macaluso, 2003). In general, triplets have
been invaluable sources of information about the effects of heredity on human behavior, but these triplets had
two especially noteworthy attributes: (1) they were monozygotic and (2) they were discordant for sexual
orientation. One brother (henceforth to be referred to as HM) identified himself as homosexual, whereas the
other two brothers (henceforth to be referred to as HT1 and HT2) identified themselves as heterosexual.
Clearly, if cognitive abilities differ between homosexual and heterosexual men, one would predict that HM's
performance across a series of tests of cognitive abilities would exhibit a pattern different from those of HT1
and HT2. This represented a strong test of the hypothesis, for one would expect that the triplets' monozygosity
would diminish these differences. All three agreed to participate in a study examining this hypothesis, but were
unaware of specific predictions.
METHOD
Participants
It was instructive to examine the triplets' personal perspectives on developmental issues relevant to their
discordant sexual orientation. The second author acquired this material during telephone interviews conducted
separately with each triplet as part of an ongoing book project. The triplets, who were naturally conceived,
were born on July 18, 1975, making them 21 years of age at the time of the interviews. They were delivered
vaginally in a vortex position and born 3 and 4 min apart. Their birth occurred 6.5 weeks prematurely,
requiring incubation of all three infants in a high-risk nursery. They were healthy but, given the lung difficulties
associated with premature births, it became critical to monitor their early breathing; however, breathing
problems never developed.
The family was Caucasian and middle class. The mother was 30 years of age and the father was 35 years of
age at the time of their birth. The parents already had an older son who was 20 months of age at the time.
Having triplets was regarded as a positive experience by their mother and father. The infants were color coded
in blue (HT1), red (HM), and green (HT2), with respect to birth order, to tell them apart. Their birth weights
were 4 lb, 1 oz; 3 lb, 14 oz; and 4 lb, 0 oz, respectively. They arrived home individually, HM at 9 days, HT1 at
5 days, and HT2 at 7 days so as not to overwhelm their older brother. They developed no remarkable illnesses
or allergies, although colds and stomach flu occurred frequently. They were not nursed, but were administered
a variety of formulas with medications to relieve their colic that persisted for 6 months. They began sleeping
regularly at approximately 8 months of age.
Two sources of information were instructive: (1) home videotapes made of the triplets as young children and
(2) HM's recollections of childhood perceptions and feelings. "It's all clearer looking back," he remarked. In the
films, HM's mannerisms and reactions were perceived by family members as strikingly different from those of
his two brothers. In fact, their mother referred to him as her "sensitive, artistic one." His cotriplets were known
as the "stubborn one" and the "athletic one." Other commonly used descriptive terms were "delicate," "willful,"
and "cocky," respectively. There was a scene in one video in which one triplet (then age 6) is boxing with his
older brother, leaving HM and HT1 to spar with one another; however, HM was crying because he did not want
to participate.
When HM was "little," he recalled being at a ball game and visiting the restrooms at the stadium. There he
experienced a fascination with the opportunity to inspect the variety of male genitalia. He was aware that many
children "like to look," but his remembrance of this experience was extremely "vivid." It was a feeling that has
not abated. At age 17, he became fixated on a high school teacher much older than he. During his high school
years, HM coped, in part, by "hiding behind" his two brothers. When HM directly revealed his sexual preference
to his brothers in college, it did not completely surprise them.
Following high school graduation, the triplets attended the same university away from home where they
variously roomed together and apart during the next 4 years. HM majored in theater and psychology, HT1
majored in journalism, and HT2 majored in education and health. Their occupations at the time of the interview
were hospital consultant, project coordinator for telecommunications, and medical supplier, respectively. HM
was currently living at home and making plans to move out on his own. HT1 was married, and HT2 was
unmarried and living out of state.
The triplets' differing sexual orientations have not impaired the strong social bonds they have always felt for
one another. In this respect, they resembled the majority of other MZ twins and triplets for whom the social
relationship is profound and enduring (see Segal, 2000). All believed they were treated equally and fairly by
both parents.
Before commencing the study, the monozygosity of the triplets was confirmed through four sources of
information, ordered here from weakest to strongest: (1) the parents of the triplets were certain of their sons'
zygosity, having been informed of this by the attending physician; (2) responses to a standard zygosity
questionnaire, which included items about adult height, weight, eye color, hair texture, and hair curliness;
4. whether strangers, friends, or family members confused them; and whether they were as "similar as two peas
in a pod"; (3) the mother's report that the triplets shared the same placenta; and (4) blood samples that were
typed for 18 polymorphic markers.
Over the course of a semester, a number of cognitive ability, personality, and biographical measures were
administered to the triplets. The triplets also underwent audiometric, anthropometric, and speech and voice
measurement in various laboratories at the university. These assessments were completed by trained
individuals blind to the triplets' zygosity and sexual orientation status. One projective test of personality and
psychological functioning, the Rorschach, was administered by a trained clinical psychologist, who was also
blind to the triplets' zygosity and sexual orientation status. The first author and a clinical psychologist, different
from the one who administered the test, scored the Rorschach.
The first author obtained Institutional Review Board approval from his university where the data were collected.
Informed consent was obtained from the triplets prior to the beginning of the study. Permission was also
obtained from the triplets to submit a final report of the study's results for publication. Before its submission,
the triplets reviewed the present report of the study and approved its contents.
Measures
The measures used in this report are listed in Table I.
Sexual Orientation and Behavior
To more confidently label the triplets as either "homosexual" or "heterosexual," a sexual orientation and
behavior questionnaire was administered. This questionnaire consisted of items that asked respondents to
identify their sexual orientation, to describe their sexual fantasies and behaviors involving partners of both
sexes from 12 to 18 and from 19 to 21 years of age, to reveal the number of lifetime sexual partners of both
sexes, and indicate the age at which their sexual orientation was revealed to others if they ever did so.
Rorschach HS (Schafer Homosexuality Signs). Schafer (1954) proposed a set of nine signs of male homosexual
orientation. These signs are as follows: (1) reversal, combining, blurring, and arbitrary assignment of sex
characteristics; (2) feminine emphasis; (3) reference to perversions; (4) hostile, fearful conception of
masculine role; (5) hostile, fearful, rejecting characteristics of women; (6) preoccupation with feminine bodies
and pleasures; (7) anal perspective and preoccupation; (8) castration emphasis; and (9) general increase in
sexual imagery. The percentage of total responses (R) that are Schafer signs (HS%) can be used as an
indicator of male homosexual orientation. Schafer signs have been shown to successfully differentiate male
homosexuals from male heterosexuals (Andersen & Seitz, 1969; Hooker, 1958; Raychaudhuri & Mukerji, 1971;
Seitz, Andersen, & Braucht, 1974).
The Minnesota Multiphasic Personality Inventory--2: Homosexuality Scale. Panton (1960) proposed a
homosexuality scale (HSX), on the basis of his finding that 22 items from the original version of MMPI
significantly distinguished homosexual from heterosexual men. Subsequent studies also found that the HSX
scale distinguished homosexual and heterosexual men (Krippner, 1964; Pierce, 1972). In MMPI-2, 17 of the 22
items remained, which permitted the creation of an HSX score for each of the triplets.
Sixteen Personality Factor Questionnaire (16PF). Sixteen primary factors and five global personality factors are
measured by 16PF (Cattell, Eber, & Tatsuoka, 1988). Of particular interest were three scales that differed
significantly between men and women in the normative sample: warmth, dominance, and sensitivity. Thus, one
hypothesis might be that heterosexual and homosexual men differ significantly on these three scales as well;
however, it turns out that differences between heterosexual and homosexual men have been better
represented by profile differences across all 16 personality factors (Bernard & Epstein, 1978).
Anthropometric
A series of anthropometric measurements was obtained, including detailed measures of head and facial
dimensions and fingerprints. A graduate student in physical anthropology made these measurements, blind to
the zygosity and sexual orientation of the triplets. A colleague, Dr Lynn Hall, an expert on dermatoglyphics who
has published studies on finger ridge patterns and sexual orientation (e.g., Hall, 2000), measured the
fingerprint ridge count on both the left and the right hands of the triplets. She was also unaware of their
zygosity and sexual orientation.
Speech and Voice
Audio recordings were made of the triplets reading the first section of the Rainbow Passage (Fairbanks, 1960),
counting to 20, and reading lists of words containing the four vowels, /a/, /i/, /u/, /ae/; the three syllabi,
/pa/, /ta/, /ka/; and the three words, /kait/, /piknik/, and /dag/. From these recordings, several speech and
voice measures were extracted for each of the triplets using the Computerized Speech Lab-Model 4300B and
the DSP Sona-Graph, both manufactured by Kay Elemetrics.
Fundamental Frequency. Fundamental frequency (FO) is the vibratory rate of the vocal cords, as measured in
hertz (Hz), and is synonymous to the more common term, pitch. FFO is a function of the length and density of
the vocal cords, as well as the amount of stress placed on them during speech. This measurement reflects the
"physiological limits" (strength) of the voice. For adult men the average FO is 125 Hz during normal
conversation, whereas for adult women the average is 215 Hz (Colton & Casper, 1996). The sex difference for
fundamental frequency, which occurs for several other speech measures, has been primarily attributable to the
shorter (by 15%) vocal cords of adult women.
Formant Frequencies. Each vowel sound has several characteristic amplitude peaks (measured in Hz), two of
5. which are first formant (F1) and second formant (F2). F1 has the lowest frequency peak and F2 the second
lowest. The frequencies at which formants occur depend on the length of the vocal cords, the tongue position,
and the height of the tongue. Different vowels have been distinguished by different formant frequencies. For
neutral vowels, the average value of F1 has been 500 Hz in adult men, whereas the average value for F2 has
been 1,500 Hz. For adult women, the values have been 600 and 1,800 Hz, respectively (Pickett, 1999).
Speech Rate. The number of syllables produced in 1 s (syllables/seconds) is referred to as the speech rate.
Women have typically shown higher speech rates than have men (Feldstein, Dohm, & Crown, 1993; Nicholson
& Kimura, 1996; Wu & Childers, 1991).
Total Duration. Total duration is the total amount of time (in second) to produce one syllable, including
respiration and pauses.
Vowel Duration. Vowel duration is the length of time (in millisecond) to produce one vowel, less the time spent
on respiration and pauses.
Word Duration. Word duration is the length of time (in millsecond) to produce one word, syllable, or number,
less the time spent on respiration and pauses.
Men have typically shown longer total, vowel, and word duration times than women (Avery & Liss, 1996).
Because significant sex differences have been found for all of the above measures of speech and voice, sexual
orientation differences were predicted as well.
Masculinity-Femininity
Rorschach M (Human Movement Responses). Rorschach M scores are a count of human movement responses.
A response is scored as a human movement response if it is characterized by one of the following: (1) human-
like action attributed to a portion of a figure; (2) animals in human-like action; (3) caricature and statues in
human-like action; (4) human facial expressions; and (5) human-like facial expressions in animals.
Rorschach M% (Femininity). Evidence exists that the percentage of human movement responses (using R as a
base) can be interpreted as a measure of femininity. Coursol (1996). Kleinman and Higgins (1966), and
Raychaudhuri and Rabindra (1971) found that M% was significantly higher in adult females than in adult
males. Additionally, Raychaudhuri and Rabindra (1971) reported that M% predicted femininity in adult males.
Results reported by Benveniste (1995) and Voigt (1966) indicated interrater reliability for scoring responses as
human movement.
Rorschach B (Barrier Responses). Barrier responses are those attributable to concern for the vulnerability of
the human body, and more broadly, interest in erecting barriers between the respondent and the outer world.
A response was characterized as a barrier response if it included at least one of the following: (1) animals
wearing clothing; (2) humans wearing unusual clothing; (3) reference to the skin of an animal; (4) enclosed
openings in the earth (e.g., wells); (5) animals used as containers (e.g., milk in cow udders); (6) overhanging
or protective surfaces (e.g., umbrellas); (7) armored objects; (8) covered, surrounded, or concealed objects,
people or animals; (9) objects with container-like properties or shapes (e.g., chairs); (10) vehicles; and (11)
buildings. Most studies have reported interrater reliabilities for barrier responses above. 90 (e.g., Fisher &
Cleveland, 1958).
Rorschach P (Penetration Responses). Penetration responses include references to penetrating boundaries. A
response was characterized as a penetration response if it included at least one of the following: (1) open
human or animal mouths; (2) penetrating objects; (3) injured or degenerated objects, people, or animals; (4)
boundary-less openings (e.g., a bottomless lake); (5), transparent objects; and (6) all other types of openings
(e.g., the anus). As in the case of barrier responses, penetration responses have also been reliably identified by
different raters (e.g., Fisher & Cleveland, 1968).
[[|B-P|]/[B+P]] X 100 (Femininity). Several researchers have found that women obtain significantly higher
barrier scores than do men and that men obtain significantly higher penetration scores than do women (e.g.,
Fisher, 1964; Fisher & Cleveland, 1968; Hartley, 1967). Thus, a comparison between barrier and penetrations
scores might provide some indication as to the "femininity" of the respondent.
Bem Sex Role Inventory. The Bem Sex Role Inventory (BSRI; Bem, 1974) is a 60-item measure of masculinity,
femininity, and androgyny, in which respondents rank each item as to how well the adjective describes them.
Twenty of the items are stereotypically feminine, 20 are stereotypically masculine, and 20 are gender neutral.
The masculinity items can also be interpreted as measuring "instrumentality"; the femininity items can be
interpreted as measuring "expressiveness" (Lippa, 2002). Items are scored from 1 (never or almost true) to 7
(always or almost always true). Bem reported Cronbach's alpha reliabilities of .80-.86 for femininity and
masculinity, respectively. Comparable alphas have been reported from other studies (e.g., Ballard-Reisch &
Elton, 1992). The test-retest reliability of BSRI, over an 8-week period, has been .80 for femininity, .93 for
masculinity, and .86 for androgyny (Rowland, 1977). Other studies have shown that BSRI correctly assigned
individuals to their sex-role classification on the basis of external criteria (Myers & Finn, 1985).
The Boyhood Gender Conformity Scale. The Boyhood Gender Conformity Scale (BGCS; Hockenberry &
Billingham, 1987) consists of 20 items constructed to classify adult male respondents for sexual orientation on
the basis of their reported boyhood gender conformity or nonconforming behavior and identity. Each item is
scored from 0 (Never or almost never true) to 6 (Always or almost always true). Ten of the items are
"masculine," and the other 10 are "feminine." The 10 masculine items are reverse scored to be in the feminine
direction so that higher scores represent higher levels of gender nonconformity. In BGCS, the mean of the 20
6. items for homosexual males was 2.96, and for heterosexual males, the mean was 1.80. The authors reported a
test-retest reliability of .92 after a 2-week interval based on discriminant function scores obtained from a
discriminant analysis of 13 of the scale's items. Indicative of the scale's validity, the discriminant analysis
correctly classified homosexual and heterosexual respondents. Phillips and Over (1992) also found that BGCS
significantly discriminated homosexual from heterosexual respondents. The average of the 20 BGCS items was
reported for each triplet in this study.
The Minnesota Multiphasic Personality Inventory--2: Masculinity-Femininity Scale. The masculinity-femininity
scale (Mf-m) is a 56-item scale derived from the 567 items of MMPI-2. According to the authors of MMPI, this
scale measures respondents' nonconformity to gender roles (including homoerotic sexual fantasies) and to
several variables on which men and women differ (Hathaway & McKinley, 1989). The scale's mean based on
the normative sample is 26.01 (SD = 5.08).
Cognitive
Rorschach R (Response Productivity). R is the total number of responses given to the inkblots. Typically, more
than one response is given to each inkblot. If response quality is adequate, R can be interpreted as a measure
of general intelligence or creativity (Aronow & Reznikoff, 1976).
Rorschach A (Animal Content Responses). The Rorschach A is the total number of responses that include
references to animals.
Rorschach 1-A% (Intellectual Functioning). This score, which is a function of the percent of the total number of
responses (R) which are A, can be used as a measure of general intelligence (e.g., Klopfer, Ainsworth, Klopfer,
& Holt). Ramzy and Pickard (1949) reported an interrater reliability of .99. As evidence of its validity as a
measure of general intelligence, 1-A% correlates significantly with Raven's Progressive Matrices (Wysocki,
1957), the Wechsler Adult Intelligence Scale (Consalvi & Canter, 1957), and college performance (Rust & Ryan,
1953).
Water Level Task. The triplets completed a paper-and-pencil version of the water-level task (Wegesin, 1998).
The triplets were first shown an outline drawing of a jar capped with a cork. The jar was resting cork-side up on
a horizontal line that was identified as a "table." The triplets were told that the jar was half-full of water as
indicated by the horizontal line (the "water" line) parallel to the table. The triplets were told that on the
following pages the jar would be shown in various orientations and that they were to draw the water line as it
should appear using a pencil and a straight-edge. The jar was depicted in eight different orientations (1, 2, 4,
5, 7, 8, 10, and 11 o'clock) arranged in a random sequence. Each item was scored as correct (if a triplet's line
was within 4[degrees] of the horizontal); otherwise, it was incorrect.
Mental Rotation. The triplets were allowed a total of 6 min to complete the 20 items on the Mental Rotation
Test (Vandenburg & Kuse, 1978). This test required participants to identify which of four stimuli can be
produced by mentally rotating a target stimuli. Each test item had two correct and two incorrect choices. On
each item, participants received 2 points if they marked both correct choices and 1 point if they marked only
one correct choice. All other responses received a score of 0 for the item.
Shipley-Hartford Vocabulary Test. The Shipley-Hartford Vocabulary Test is a paper-and-pencil test composed of
a list of 40 target words. The correct synonym to each target word was selected from among a group of four
words beside each target word.
The Educational Testing Service Kit of Factor-Referenced Cognitive Tests. All 72 tests of the ETS Kit of Factor-
Referenced Cognitive Tests (Ekstrom, French, & Harman, 1976) were administered. These 72 tests were
constructed to act as "marker" tests for 23 factors of cognitive ability. The psychometric characteristics of the
Kit have been examined extensively (e.g., Ekstrom et al., 1976).
RESULTS
Each triplet was certain about his sexual orientation upon entering the study. This was confirmed by the sexual
orientation results presented in Table II; however, several responses were of note. First, HM experienced a
notable change in his Kinsey rating for sexual feelings and behavior between the period from 12 to 18 years of
age (Kinsey 2) and from 19 to 21 years of age (Kinsey 6). This change represented a change of sexual feeling
and not a change of sexual behavior. Before the age of 19, HM had entertained the idea that he might possibly
be bisexual on the basis of the partial heterosexual content of his fantasies and his desire to have female
dating partners, but he now dismissed this possibility at the time of testing, fully endorsing an exclusive
homosexual orientation. When the first author interviewed HM, he had the impression that HM's relationships
with girlfriends were not substantively serious, not progressing beyond flirtation. HM first had sex with another
male at 18 years of age; he has never had sex with a female. At 19 years, HM first defined himself as
exclusively homosexual in feeling and behavior. It was interesting to note that although HM reported having
sex with 14 different male partners, he had not had sex in the past year.
A second notable result reported in Table II was HT1's strong endorsement of the "desirability of having male
sexual partners." This appeared anomalous, considering his Kinsey score of 1 for sexual feelings and behavior.
When asked specifically whether he "had ever been sexually attracted to a man or boy," HT1 responded "not
sure." HT1 has never had sex with another male, although he did report having had nine different female
sexual partners, only one of which was during the past year. This single female partner, whom he eventually
married at 24 years of age, was from a committed relationship. Thus, the reason as to why HT1 would report
at 21 years of age that the idea of having sex with another male was "desirable," especially when in a
7. committed relationship with a female, was unclear.
Another notable anomaly of HT1's scores in Table II is his high HSX score. As explained in the Discussion, this
result is probably related to HT1's relatively high MMPI-2 masculinity-femininity score in Table V; it is very
likely that HSX scores partly reflect gender nonconformity, perhaps as much as they reflect sexual orientation.
Table II also reports Schafer homosexuality (HSX) scores for the triplets that are consistent with their self-
identified sexual orientations: HM's score was the highest; HT1's and HT2's scores were considerably lower and
more similar to each other's than either was to HM's score. The two raters who scored the Rorschach for
Schafer signs differed by only four responses for HM, and by only two responses for HT1 and HT2; thus the two
raters' scores were averaged.
Table III shows the anthropometric measurements. Given their monozygosity, it was not surprising that they
showed little difference on most of the physical traits. The only exception was the difference between the right-
and left-hand ridge counts. HT1's left-hand ridge count was much greater than that for his right hand, whereas
for HM and HT2, the right-hand ridge count was greater, although disparity between the two hands was much
less. Thus, whereas the results for HT1 and HM were as predicted, the results for HT2 were not: In fact, HT2,
who on most indicators was the most masculine of the triplets, had a ridge count disparity most consistent with
the disparity of a homosexual male.
Table IV reports sexual orientation differences for the speech and voice measures. As predicted, with the
exception of /a/, the fundamental frequency (FO) means indicated that HM spoke with a higher pitched (in a
female direction) voice than did his brothers. For example, HM's mean oral reading frequency was 176.9 Hz,
whereas HT1's and HT2's frequencies were 155.0 and 148.4 Hz, respectively. Also as predicted, HM had higher
formant frequencies (agin in the female direction) on a greater number of vowels than did his brothers. For
instance, HM's F1 frequency for /a/ was 520 Hz, whereas HT1's and HT2's F1 frequencies were 500 and 460
Hz, respectively. However, there were a few exceptions reported in Table III: HM's F1 frequency was lower
for /i/ than are both of his brothers' frequencies, is lower than HT2's frequency for F1 on /ae/, and is equal to
at least one of his brothers' frequencies on F1 for /u/. On the other hand, there was little difference among the
brothers for the speech rate of oral reading. Lastly, total duration, vowel duration, and word duration have
been shown to be longer in women than in men. Consistent with these findings were the sexual orientation
differences shown in Table IV, with HM mostly having longer duration times than HT1 and HT2.
The results from measures of masculinity-femininity are provided in Table V. Clearly, HM consistently obtained
scores indicating a greater degree of femininity compared to his brothers. In addition, the brothers maintained
a consistent ordering for each measure: HM was most feminine, HT1 was in the middle, and HT2 was least
feminine. As for the Schafer signs, the two raters were in substantial agreement in scoring the Rorschach for
human movement, femininity, barrier, and penetration responses. At most, the two raters disagreed by three
responses on any of the scores; in such cases, their two scores were averaged.
Fig. 1 plots the 16PF profiles of the three brothers. The prediction was that the 16PF profile of HM would differ
from the profiles of HT1 and HT2. This was indeed the case for 10 of the 16 personality factors. In contrast to
his brothers, HM (represented by the bold line) could be characterized as more intelligent (B+), more affected
by feelings (C-), more expedient (G-), more tenderminded (I+), less conventional (M+), more guilt prone
(O+), more open to new experiences ([Q.sub.1]), more self-sufficient ([Q.sub.2]), less controlled emotionally
([Q.sub.3]), and more tense and frustrated ([Q.sub.4]). On the basis of a scoring system suggested by Krug
(1981), HM could be described as moderately extraverted, highly anxious, low in tough-mindedness,
moderately independent, and low in self-control. This pattern has often been seen particularly in those who
have a mild degree of conflict in interpersonal relationships. This pattern suggested that HM liked to be around
people, but found them difficult to accept at face value; and was outgoing, but intimidated by social situations.
Low tough-mindedness was also indicative of low masculinity/high femininity. Individuals with HM's profile have
scored highest on the 16PF career theme scale of nurturing-altruistic (e.g., physician) and have scored lowest
on the mechanical-operative scale (e.g., machine operator).
The profiles of HT1 and HT2, while more similar to each other than to the profile of HM, showed some
differences. HT1 could be described as someone who took a practical approach to life, was not very flexible,
and was highly dependent, whereas HT2 had a less practical approach to life, was more flexible, but was still
highly dependent. Both HT1 and HT2 were more masculine than HM. Individuals with HT1's and HT2's profiles
have scored highest on the 16PF career-theme scales of procedural-systematic (e.g., navy officer) and
venturous-influential (e.g., sales manager), and lowest on nurturing-altruistic (e.g., Cattell et al. 1970).
Correlations among the triplets' 16PF profiles also provided evidence of personality differences between HM and
HT1/HT2. The correlations between the profile of HM with the profiles of HT1 and HT2 were -.27 and -.43,
respectively, whereas the correlation between the profiles of HT1 and HT2 was .48. To examine whether sexual
orientation differences were related to sex differences, two difference scores were computed for each of the
16PF scales: (a) the difference between HM and the average of HT1 and HT2 and (b) the difference between
males and females from the normative sample results reported by Cattell et al. (1970, p. 70). The correlation
between sexual orientation differences and sex differences across the 16PF scales was .35.
[FIGURE 1 OMITTED]
Table VI provides the results of several cognitive ability measures. These results are in line with our
predictions: On the water level and mental rotation tasks, HM did least well; on the vocabulary test (analogous
8. to the negligible difference found between men and women), the triplets did not differ greatly. Interestingly,
the Rorschach variables indicated that HM was more intelligent than were his two brothers, or at the very least,
more creative.
To compare the cognitive ability profiles of the triplets, multidimensional scaling was used to construct a set of
coordinates for each of the 23 ETS factors of cognitive ability. Determined by coordinate values, the ordering of
the triplets on a dimension indicated how similar the triplets were to each other on the cognitive ability factor.
From these coordinates, distances were computed between each of the triplets. Our hypothesis was that the
distance between HM and both HT1 and HT2 would be greater than the distance between HT1 and HT2. The
similarity coefficients in the association matrix used for the scaling were computed by taking the ratio of each
triplet's performance to each of the other triplets' performance, resulting in six similarity coefficients for each
cognitive ability. These six coefficients were placed into an asymmetric 3 X 3 association matrix, with the three
brothers defining the rows and columns of the matrix. Zeros were placed in the main diagonal of the matrix,
indicating that a triplet was not to be compared to himself.
Table VII details the results of the multidimensional scaling. Visual inspection of the table indicated that HM lies
further away from HT1 and HT2 than HT1 and HT2 did from each other. This was confirmed by the average
computed for each of the distances: The two average distances between HM and his two brothers were
significantly greater than the distance between HT1 and HT2.
To further emphasize the differences between the cognitive ability profiles of the homosexual and heterosexual
triplets, Fig. 2(a) and (b) graph the three profiles together, with the bold line representing HM's performance
and the dashed lines, HT1's and HT2's performance. The differences between the homosexual and heterosexual
profiles were striking: the correlations between the profile of HM with the profiles of HT1 and HT2 were -.90
and -.89, respectively, whereas the correlation between the profiles of HT1 and HT2 was .60. To examine
whether sexual orientation differences were related to sex differences, two difference scores were computed for
11 of the 23 cognitive ability factors: (a) the difference between HM and the average of HT1 and HT2 and (b)
the difference between males and females from the normative sample results reported by Ekstrom et al. (1976,
pp. 11-15). (Ekstrom et al. only reported normative data by sex for 11 of the cognitive ability factors.) The
correlation between sexual orientation differences and sex differences across the 11 cognitive abilities was .43.
DISCUSSION
The bases of sexual orientation have been explained with reference to multiple explanations, variously
emphasizing genetic, biological, and experiential effects, as indicated above. It is impossible to determine the
precise blend of causal factors eventuating in discordant sexual preferences among this MZ male triplet set.
The finding that HM (but not his two brothers) showed signs of gender nonconformity as a child was consistent
with previous findings in the twin literature. Specifically, gender nonconformity has been reported by both
cotwins in male and female MZ twin pairs concordant for homosexuality, but only by homosexual cotwins in
discordant pairs (Bailey & Pillard, 1993). The fact that this behavior appeared quite early in HM suggests either
prenatal hormonal differences among the triplets and/or a genetic predisposition environmentally triggered in
only one cotriplet as possible explanations.
While predictable from a neurohormonal theory of sexual orientation, the dramatic difference between the
cognitive profiles of the homosexual and heterosexual cotriplets was still surprising, given the triplets' genetic
identity. Because significant genetic effects have been found for most cognitive abilities (Sternberg & Kaufman,
1998) and for sexual orientation (Bailey & Pillard, 1995), cotwins and cotriplets are generally very similar in
sexual behavior and cognitive ability. If one accepts that sexual orientation explains some of the cognitive
ability differences between cotwins and cotriplets, then what explains sexual orientation differences between
them? Genes are not the sole influence on the development of sexual orientation, and it might well be that
differences in androgenic exposure prenatally are attributable to unique intrauterine conditions not under
genetic control for prehomosexual cotwins or cotriplets. In fact, in some respects, twins and triplets, especially
MZ, are subject to prenatal environmental effects that differ from those of their cotwins or cotriplets, the most
well known of which is birth weight (Martin & Hershberger, 2001). It is not at all unusual to observe greater
differences in birth weight between MZ than DZ twins.
Various theories have been proposed to explain how siblings occupying the same womb, either simultaneously
or sequentially, might be exposed to different prenatal androgenic patterns. One theory proposed that the twin
sisters of twin brothers or the twin brothers of twin sisters are exposed to the androgenization pattern of the
opposite sex (Miller, 1994); the evidence for this theory in humans is tenuous at best, although strong in
nonhuman animals (Rose et al., 2002). A theory similar to the opposite-sex hormonal exposure theory has
concerned the possible variations in hormonal exposure that accompany different intrauterine positions (Ryan
& Vandenbergh, 2002). Again, the evidence for the validity of this theory in humans has been questionable. In
nonhuman animals, however, Clark, Vonk, and Galef (1997) have found intrauterine position to be associated
with a number of sexually dimorphic characteristics: postnatal responsiveness to and levels of testosterone,
fertility, sexual virility, sexual position, paw preference, social dominance, and muscle size. For human
singletons, strong evidence exists that a late fraternal birth order in men is associated with homosexual
orientation (Blanchard & Bogaert, 1996). It has been hypothesized that this fraternal birth order effect results
from the progressive immunization of some mothers to Y-linked minor histocompatability antigens (H-Y
antigens) by each succeeding male fetus, and its subsequent effect on the future sexual orientation of each
9. succeeding male fetus (Blanchard, 2001).
[FIGURE 2 OMITTED]
Another explanation for sexual orientation differences could lie in the timing of zygotic splitting. (4) MZ twins
result when a single fertilized zygote divides between the 1st and 14th days after conception (Bryan, 1992). If,
during this period of time, one of the halves of the zygote itself splits, MZ triplets result. Thus, it is possible for
several days to pass before the second splitting occurs. Given that the results were generally ordered as HM,
HT1, HT2, we can speculate that HM and HT1 resulted from the first zygotic split, and HT1 split to create HT2.
This time lapse between the first and second splitting might place HM on a developmental course different from
the other two triplets. One way in which the developmental course may differ for HM is described by
developmental instability theory (Gangestad, Bennett, & Thornhill, 2001). Developmental instability theory
suggests that homosexuality might be due to general developmental disruption, which produces a shift from
the developmental trajectory of sexual orientation from the typical heterosexual preference (Lalumiere et al.,
2000). These "developmental disruptions" (e.g., chromosome mutations), experienced by HM alone, are
offered as an alternative to exposure to atypical hormone patterns as an explanation of homosexuality.
The placental status of the triplets may also create developmental differences between one triplet and the
other two. Under our scenario, HM and HT1, sbecause they resulted from early zygotic splitting, will likely have
separate placentas (giving the appearance of one). It is very rare for triplets to share a placenta (Luke &
Eberlein, 1999). On the other hand, the later zygotic split that hypothetically produced HT2 from HT1 may have
resulted in a fused placenta, especially if the split occurred towards the end of the 14-day period following
conception (Bryan, 1992). Late splitting is associated with opposite-handedness and we know that HT1 is left-
handed. The separate or fused status of twins' placentas has been found to be related to twin concordance or
discordance for some traits (e.g., schizophrenia: see James, Phelps, & Bracha, 1995; personality; see Sokol et
al., 1995). Therefore, the sexual orientation difference among the triplets may have arisen from the status of
their placenta. Unfortunately, the placental characteristics of HM, HT1, and HT2 cannot be reliably determined.
Speculation suggests that developmental disruption from zygotes splitting and/or maternal immunization to H-
Y antigens (from having delivered a male child, then three triplets) affecting HM could be contributing factors.
HM was the lightest at birth, although he differed by 2 oz from HT2.
Although genes or hormones or both play a substantial role in the development of sexual orientation, the
correlation between genes and nonshared environments are important, as well (e.g., Kendler, Thornton,
Gilman, & Kessler, 2000). Nonshared environments are environmental experiences unique to an individual.
Genotype-environment correlation (CovGE) refers to a correlation between the genetic and environmental
influences affecting a trait. As in any other correlation, where certain values of one variable tend to occur in
concert with certain values of another variable, a significant CovGE represents the nonrandom distribution of
the values of one variable (genotype) across the values of another variable (environment). CovGE may be
consequential for sexual orientation development, because when CovGE is present, we would expect different
phenotypes to be selectively exposed to environmental experiences based upon their differing genetic
propensities.
One area in which CovGE is likely to be of importance is the behavior of parents towards their children.
Although the triplets asserted that they were equally and fairly treated by their parents, it is likely that, given
their differing behavioral styles and corresponding nicknames, their mother and father did not treat them
exactly alike, but modified their parenting practices in response to the behaviors expressed by each of their
three sons. A substantial body of studies supports the view that parents respond to, rather then create,
behavioral differences among twins and siblings. This would be a form of "reactive" genotype-environment
covariance (Reiss, Neiderhiser, Hetherington, & Plomin, 2000). Even if parents tended to treat MZ twins alike
or different, this would probably be of little consequence for the development of sexual orientation. A
substantial body of research has suggested that, in general, treating MZ twins alike or different has not been
related to behavioral similarities and differences (Loehlin & Nichols, 1978; see also Segal, 2000). Research
specific to the relation between differences in parental treatment and sexual orientation has been focused
largely on the "rejecting father" theory of sexual orientation development, whereby fathers have been closer
and warmer towards their future heterosexual male children than their future homosexual male children, who
were kept at an emotional and physical distance (Ellis, 1996).
One interesting measurement issued suggested by this study, and in others that attempt to measure both
sexual orientation and masculinity-femininity, was the construct distinctiveness of sexual orientation and
masculinity-femininity scales. Recall that HT1, who reported that he found the idea of having sex with other
men desirable, had an MMPI-2 masculinity-femininity score very similar to HM's score. Lack of construct
distinctiveness was especially likely when the two scales have been created from subsets of items from some
larger, more general scale: Because both the masculinity-femininity scale and the HSX (homosexuality scale)
were derived from items from MMPI-2. HSX scale may simply have been another measure of masculinity-
femininity.
Several observations about the scales' items suggest that HSX may, in part, have been a measure of
masculinity-femininity. First, the two scales share five items in common: liking the work of a librarian,
collecting flowers or growing houseplants, indulging in unusual sex practices, frequently worrying, and liking
the work of a building contractor. Furthermore, each of these five items was scored in the same masculine-
10. feminine direction on both scales. For instance, a "true" response to liking the work of a librarian was scored in
a feminine direction on both HSX and MMPI masculinity-femininity scales. In addition, although five items may
not have appeared to be a large number to have in common, considering that the masculinity-femininity scale
consisted of 56 items (5/56 = 8.93%), when looked at in terms of the 17 items on HSX, it was substantial: five
items were 29.41% of the total number of items on HSX. On the other hand, the fact that the HSX scale does
not contain many of the "obvious" occupation and hobby/interests items that are in the MMPI-2 masculinity-
femininity scale (and which are found on most measures of masculinity-femininity) supports the construct
distinctiveness of the two scales: for example, in addition to asking about liking the work of a librarian or a
building contractor, the masculinity-femininity scale has items asking about liking to be a singer or a florist.
Altogether, the masculinity-femininity scale has 11 occupation and 7 hobby/interests items. In addition, if the
HSX scale were simply another measure of masculinity-femininity, one would expect that of all the masculinity-
femininity items, item 62 of MMPI-2, "I have often wished I were a girl," would have distinguished homosexual
from heterosexual males in Panton's (1960) original study. Given the difficulty in distinguishing the meaning of
responses to sexual orientation scales from masculinity-femininity scales, studies should, as in the present one,
use several measures of each. If only a single measure of each construct is possible, then at the very least, the
two measures should not have items in common; that is, they should not be derived from the same scale.
In summary, this study has shown that MZ cotriplets, despite their genetic identity, manifested substantial
differences in sexual orientation, cognition, personality, and gender conformity. The common source of these
interrelated differences was thought to be attributable to differences in prenatal androgen exposure. Further
insight into the origins of sexual orientation could be obtained if the how and why of differences in prenatal
androgenization between MZ twins or triplets become the focus of intense study.
Table I. Study Measures
Category Measure
Sexual orientation and Self-identification; fantasies; number of sex
behavior partners; sexual orientation disclosure;
Rorschach Schafer homosexuality signs;
Minnesota Multiphasic Personality Inventory--
2: Homosexuality Scale; 16 Personality Factor
Questionnaire
Anthropometric Height, weight, and shoe size; Nose and head;
height, breadth, and length; Handedness;
Fingerprint ridge count
Speech and voice Fundamental frequency; Formant frequencies;
Speech rate; Total, vowel, and word duration
Masculinity/femininity Rorschach: human movement responses,
femininity, barrier responses, and penetration
responses; Bem Sex Role Inventory; Boyhood
Gender Conformity Scale; Minnesota Multiphasic
Personality Inventory--2: Masculinity-
Femininity Scale
Cognitive Rorschach: response productivity and
intellectual functioning; Water-level task;
Vandenburg and Kuse Mental Rotation Test;
Shipley-Hartford Vocabulary Test; Educational
Testing Service Kit of Factor-Referenced
Cognitive Tests
Table II. Measures of Sexual Orientation
Measure HM HT1 HT2
Sexual feelings and behavior:
12-18 years of age (a) 2 1 1
Sexual feelings and behavior:
19-21 years of age (a) 6 1 0
Sexual fantasies with male
partner: 19-21 years of age
(%) 98 8 5
11. Sexual fantasies with female
partner: 19-21 years of age
(%) 2 92 95
Number of lifetime male sexual
partners 14 0 0
Number of lifetime female sexual
partners 0 9 12
Desirability of having male
sexual partners (b) 5 5 3
Desirability of having female
sexual partners (b) 3 5 5
Current self-identified sexual
orientation Homosexual Heterosexual Heterosexual
Number of HW Rorschach responses 10 6 4
HW% of Rorschach responses 25.00 23.08 16.67
Number of HS (Schafer) Rorschach
responses 30 13 8
HS% of Rorschach responses 50.00 38.46 29.17
MMPI-2 HSX 9/17 11/17 8/17
(a) 0 = Sexual feelings and activity only with females; 1 = Most sexual
feelings and activity with females, but an occasional fantasy or contact
with males; 2 = Most feelings and activity with females, but some
definite fantasy or activity with males; 3 = Sexual feelings and/or
activity about equally divided between males and females; 4 = Most
sexual feelings and activity with males, but some definite sexual
feelings/activities with females; 5 = Most sexual feelings and activity
with males, but an occasional fantasy or contact with a female; 7 =
Sexual feelings and activity with males only.
(b) 1 = Totally disgusting; 2 = Slightly unpleasant; 3 = Neutral; 4 =
Somewhat sexually exciting; 5 = Very sexually exciting.
Table III. Anthropometric Measures
Measure HM HT1 HT2
Stature (cm) 170.1 172.1 171.5
Nose height (cm) 5.2 4.9 4.8
Nose breadth (cm) 3.4 3.5 3.4
Morphological facial height (cm) 12.2 12.1 12.1
Head height (cm) 25.1 25.1 24.4
Head length (cm) 20.3 20.5 20.2
Head breadth (cm) 14.7 15.1 14.8
Bizygomatic diameter (cm) 13.6 13.7 13.8
Bigonial breadth (cm) 10.4 10.4 10.6
Head horizontal circumference (cm) 23.5 23.7 23.5
Minimum frontal breadth (cm) 10.4 10.7 10.4
Weight (kg) 78.84 81.65 82.56
Shoe size (cm) 24.13 24.13 22.86
Handedness Right Left Right
Finger ridge count--right hand 70 110 61
Figner ridge count--left hand 83 64 91
Table IV. Measures of Speech and Voice
HM HT1 HT2
Measure M SD M SD M SD
Fundamental frequencies
(Hz)
Oral reading 176.9 35.8 155.0 27.9 148.4 32.3
Count to 20 183.3 27.2 141.9 7.4 137.6 21.7
14. ACKNOWLEDGMENTS This work was supported, in part, by an American Fellowship (2003-4) from the
American Association for University Women (Segal), and a grant from NIMH: R01 MH63351 (Segal).
Received March 5, 2003; revision received September 4, 2003; accepted October 30, 2003
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Scott L. Hershberger, Ph.D., (1,3) and Nancy L. Segal, Ph.D. (2)
(1) Department of Psychology, California State University, Long Beach, California.
(2) Department of Psychology, California State University, Fullerton, California.
(3) To whom correspondence should be addressed at Department of Psychology, California State University,
1250 Bellflower Blvd., Long Beach, California 90840; e-mail: scotth@csulb.edu.
-1-
Questia Media America, Inc. www.questia.com
Publication Information: Article Title: The Cognitive, Behavioral and Personality Profiles of a Male
17. Monozygotic Triplet Set Discordant for Sexual Orientation. Contributors: Scott L. Hershberger - author, Nancy L.
Segal - author. Journal Title: Archives of Sexual Behavior. Volume: 33. Issue: 5. Publication Year: 2004. Page
Number: 497+. COPYRIGHT 2004 Plenum Publishing Corporation; COPYRIGHT 2004 Gale Group