The document summarizes key concepts from Chapter 3 of Myers' Psychology textbook regarding the nature and nurture of behavior and gender. It discusses how genes contain the biological blueprint in DNA and chromosomes, and how evolutionary psychology studies the evolution of behavior. Behavior genetics examines the influence of heredity and environment on behaviors and traits. While genes and hormones influence gender, culture and social learning also strongly impact the formation of gender roles, identity, and expression.

1. Myers’ PSYCHOLOGY
(7th Ed)
Chapter 3
The Nature and Nurture
Of Behavior
James A. McCubbin, PhD
Clemson University
Worth Publishers

2. Genes: Our Biological
Blueprint
 Chromosomes
 threadlike structures made of DNA that
contain the genes
 DNA (deoxyribonucleic acid)
 complex molecule containing the genetic
information that makes up the chromosomes
 has two strands-forming a “double helix”--held
together by bonds between pairs of
nucleotides

3. Genes: Our Biological
Blueprint
 Genes
 biochemical units of heredity that make up the
chromosomes
 a segment of DNA capable of synthesizing a
protein
 Genome
 the complete instructions for making an
organism
 consisting of all the genetic material in its
chromosomes

4. Genes: Their Location
and Composition
Nucleus Chromosome Gene
Cell DNA

5. Evolutionary Psychology
 Natural Selection
 the principle that, among the range of
inherited trait variations, those that lead to
increased reproduction and survival will most
likely be passed on to succeeding generations
 Mutations
 random errors in gene replication that lead to a
change in the sequence of nucleotides
 the source of all genetic diversity

6. Evolutionary Psychology
 Evolutionary Psychology
 the study of the evolution of behavior
and the mind, using the principles of
natural selection
 Gender
 in psychology, the characteristics,
whether biologically or socially
influenced, by which people define male
and female

7. Evolutionary Psychology
 Men preferred attractive physical features
suggesting youth and health
 Women preferred resources and social status

8. Behavior Genetics
 Behavior Genetics
 study of the relative power and limits of
genetic and environmental influences on
behavior
 Environment
 every nongenetic influence, from
prenatal nutrition to the people and
things around us

9. Behavior Genetics
Identical
twins
Fraternal
twins  Identical Twins
 develop from a single
fertilized egg that splits in
two, creating two
genetically identical
organisms
 Fraternal Twins
 develop from separate eggs
 genetically no closer than
brothers and sisters, but
they share the fetal
Same Same or
environment
sex only opposite sex

10. Behavior Genetics
 Temperament
 a person’s characteristic emotional
reactivity and intensity
 Heritability
 the proportion of variation among
individuals that we can attribute to
genes
 may vary, depending on the range of
populations and environments studied

11. Behavior Genetics
 Interaction
 the dependence of the effect of one
factor (such as environment) on another
factor (such as heredity)
 Molecular Genetics
 the subfield of biology that studies the
molecular structure and function of
genes

12. Environmental
Influence
 Two placental arrangements in identical
twins

13. Environmental
Influence
 Experience affects brain development
Impoverished Rat brain Enriched Rat brain
environment cell environment cell

14. Environmental
Influence
 A trained brain

15. Environmental
Influence
 Culture
 the enduring behaviors, ideas, attitudes,
and traditions shared by a large group of
people and transmitted from one
generation to the next
 Norm
 an understood rule for accepted and
expected behavior

16. Environmental
Influence
 Personal Space
 the buffer zone we like to maintain
around our bodies
 Memes
 self-replicating ideas, fashions, and
innovations passed from person to
person

17. The Nature and
Nurture of Gender
 X Chromosome
 the sex chromosome found in both men and
women
 females have two; males have one
 an X chromosome from each parent produces
a female child
 Y Chromosome
 the sex chromosome found only in men
 when paired with an X chromosome from the
mother, it produces a male child

18. The Nature and
Nurture of Gender
 Testosterone
 the most important of the male sex hormones
 both males and females have it
 additional testosterone in males stimulates
 growth of male sex organs in the fetus
 development of male sex characteristics during
puberty
 Role
 a set of expectations (norms) about a social position
 defining how those in the position ought to behave

19. The Nature and
Nurture of Gender
 Gender Role
 a set of expected behaviors for males and
females
 Gender Identity
 one’s sense of being male or female
 Gender-typing
 the acquisition of a traditional masculine or
feminine role

20. The Nature and
Nurture of Gender
 Gender and Culture

21. The Nature and
Nurture of Gender

22. The Nature and
Nurture of Gender
 Social Learning Theory
 theory that we learn social behavior by
observing and imitating and by being
rewarded or punished
 Gender Schema Theory
 theory that children learn from their cultures
a concept of what it means to be male and
female and that they adjust their behavior
accordingly

23. The Nature and
Nurture of Gender
 Two theories of gender typing