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Asexuality: What It Is and Why It Matters
Article in The Journal of Sex Research · May 2015
DOI: 10.1080/00224499.2015.1015713 · Source: PubMed
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Asexuality: What It is and Why It Matters
Anthony F. Bogaert
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Asexuality: What It is and Why It Matters
Anthony F. Bogaert

3. Asexuality: What It is and Why It Matters
Anthony F. Bogaert
Department of Health Sciences, Department of Psychology, Brock University
In this review paper, human asexuality, a relatively understudied phenomenon, is discussed.
5 Specifically, definitions and conceptualizations of asexuality (e.g., is it a unique category
of sexual orientation?), biological and historical contexts, identity issues, discrimination
against asexual people relative to other minorities, origins, and variations including gender
differences, are reviewed. Whether asexuality should be construed as a disorder is also
discussed. The study of asexuality allows for a better understanding of an underrecognized
10 sexual minority but also affords a unique opportunity to examine and better understand
human sexuality.
In 2004, an academic paper on human asexuality
appeared in the Journal of Sex Research (Bogaert,
2004), along with a media report on the phenomenon
15 in New Scientist (Westphal, 2004). Since that time, a
heightened degree of academic and public interest in this
relatively understudied phenomenon has occurred,
including the publication of a number of theoretical
papers (e.g., Bogaert, 2006b; Chasin, 2011), empirical
20 papers (e.g., Bogaert, 2013; Brotto, Knudson, Inskip,
Rhodes, & Erskine, 2010; Prause & Graham, 2007), a
special issue of a journal (Przybylo, 2013), a review
paper (Van Houdenhove, Gijs, T’Sjoen, & Enzlin,
2014b), and many media reports (e.g., Bulwa, 2009),
25 including a full-length documentary (Chevigny,
Davenport, Pinder, & Tucker, 2011). There has also
been a book on asexuality written for both academics
and nonacademics (Bogaert, 2012b).
In the present article, many of the issues raised in
30 these recent academic publications and media sources
are reviewed. There is a particular emphasis on issues
reviewed in the recent book Understanding Asexuality
by Bogaert (2012b), which was a broad overview of
human asexuality. However, this article addresses
35 additional issues, including some raised in more recent
literature since the publication of this book. In the first
part of the present article, introductory and contextual
issues on asexuality are presented, including biological
and historical contexts, definitions=conceptualizations,
40 and prevalence. In the second part, issues related to
the development and psychological variations associated
with asexuality are presented, including its origins, gen-
der and other differences, and identity formation and
discrimination. In the third part, medical=clinical issues
45
are presented, along with a discussion of whether asexu-
ality should be construed as a disorder. Throughout
these sections, illustrations are presented on how the
study of asexuality informs the nature of human
sexuality, but a separate, later section will review these
50
examples and expand on them further. In doing so, this
paper addresses in part why studying asexuality is of
importance to sex researchers and clinicians: Aside
from gaining a deeper understanding of an understudied
sexual minority, it affords a better view of sexuality. In
55
part, this better view of sexuality may be achieved if
we attempt to see sexuality from a distance or from an
outsider’s perspective—in other words, ‘‘through the
lens of asexuality,’’ to the extent this is possible. Finally,
conclusions and future research directions are presented.
60
Note that this review is meant to address a fairly
wide range of issues and to be of interest to scholars
of different disciplines, but it is also one written by a
psychologist; thus, the psychology and closely related
biomedical=clinical aspects of asexuality are emphasized
65
throughout this review.
Introductory and Contextual Issues
Biological and Historical Context
In biology and related disciplines, the word asexual
usually describes organisms that do not use sex (e.g.,
70
male and female variations) to reproduce. Indeed,
asexuality has been the predominant form of repro-
duction for the majority of time that life has existed
on the earth (e.g., Cowen, 2005) and still exists in many
I would like to thank Kelsey Fallis and Katie Ross for their
comments on a previous draft of this manuscript. I would also like
to thank four anonymous reviewers for their suggestions.
Correspondence should be addressed to Anthony F. Bogaert,
Department of Health Sciences, Department of Psychology, Brock
University, St. Catharines, Ontario L2S 3A1, Canada. E-mail:
tbogaert@brocku.ca
JOURNAL OF SEX RESEARCH, 0(0), 1–18, 2015
Copyright # The Society for the Scientific Study of Sexuality
ISSN: 0022-4499 print=1559-8519 online
DOI: 10.1080/00224499.2015.1015713
3b2 Version Number : 7.51c/W (Jun 11 2001)
File path : P:/Santype/Journals/TandF_Production/Hjsr/v0n0/HJSR1015713/hjsr1015713.3d
Date and Time : 23/02/15 and 16:58

4. biologically simple organisms. However, some complex,
75 large-sized, but phylogenetically older animals—sharks,
for example—have the capacity to reproduce asexually
(e.g., Chapman et al., 2007). In the majority of phylo-
genetically younger animals, such as mammals (includ-
ing humans), there is no capacity to reproduce
80 asexually; reproduction only occurs sexually, through
a combining of genes from male and female variations
(Cowen, 2005).
Within sexually reproducing species, such as mam-
mals, there is often evidence that a percentage of
85 animals have no interest in, or attraction to, potential
sexual partners and are thus construable as asexual
(see section on definitions of asexuality). Lab-based
rodents, for example, have been noted for their sexual
variability. Some rodents are sometimes labeled ‘‘studs’’
90 for their hypersexualized behavior; others are labeled
‘‘duds’’ for their lack of sexual interest in partners
(e.g., Adkins-Regan, 2005). In sheep, another well-
studied group of domesticated animals, variation clearly
exists in their sexual interests=attractions (e.g., Perkins
95 & Fitzgerald, 1997; Roselli, Larkin, Schrunk, &
Stormshak, 2004). Using a controlled experimental
paradigm and special animal pens, researchers can study
rams’ sexual inclinations by allowing them access to
ewes in estrus or to other rams. The sexual inclinations
100 of the ewes are more difficult to study in such a con-
trolled setting. Most of the rams exhibit behaviors that
evince heterosexual attraction. However, a significant
minority of rams exhibit behaviors evincing marked
attraction to the same sex (i.e., other rams) or both sexes
105 (rams and ewes). There is also a significant minority of
rams showing no interest or attraction for either rams
or ewes. For example, Roselli and colleagues (2004) sta-
ted in their summary of research on these animals:
‘‘Over the past 2 years, 584 rams were tested. Of these,
110 12.5% were asexual’’ (p. 235).
Rams may provide an important animal model of
human sexuality in part because when same-sex attrac-
tions occur in these animals they seem to demonstrate
a pattern of behavior similar to same-sex behavior in
115 men (e.g., a percentage of rams actively pursue male
partners and demonstrate a seeming exclusivity toward
such partners; Perkins & Fitzgerald, 1997). As such,
other atypical orientations—no sexual attraction—in
rams may provide an important animal model of human
120 asexuality. Thus, there may be similar brain and other
developmental mechanisms giving rise to these atypical
sexual attractions in both species (see Origins section).
In a review of evidence of asexuality over human his-
tory, Bogaert (2012b) drew a number of conclusions.
125 One was that throughout humans’ ancestral history it
is very likely that a significant percentage in each gener-
ation did not mate, but this lack of sexual behavior with
partners in some individuals does not indicate they
necessarily lacked sexual interest or attraction for
130 others. Likely many factors beyond a lack of sexual
interest in (or attraction for) heterosexual partners have
contributed to a lack of partnered heterosexual behavior
throughout human history, including same-sex attrac-
tion, the often harsh exigencies of mating competition,
135
and the cultural influence on the importance of celibacy
(or abstinence from sex; see Abbott, 2001). The
latter factor—the importance of celibacy or sexual
abstinence—cannot be overstated in human cultural
history. In contrast to the often-held view in modern
140
Western society that the absence of sex is a disorder, his-
torically in many societies or within segments of society
(e.g., many religions) celibacy has been seen as a godly
virtue and something to which humans should aspire
(Sigusch, 1998).
145
A second conclusion was that much of the early
cultural record was spotty in providing evidence of his-
torical figures who were asexual, although there is some
evidence of asexuality among notable figures such as
Isaac Newton and Emily Bronte (but see White, 1999,
150
and Davies, 2004, respectively). The modern cultural
record is clearer in providing evidence of asexuality,
including famous mathematician Paul Erdos (Schechter,
1998).
A third conclusion was that, throughout human cul-
155
tural history, artists have depicted figures and characters
with an asexual aura in art and literature (e.g., Sherlock
Holmes). Modern popular media—for example, the
character Sheldon on the television show The Big Bang
Theory—also portray (quasi-)asexual characters. These
160
depictions of characters indicate that sexual variability,
including its extreme forms, have been recognized
throughout history. These depictions also illustrate that
art (e.g., literature) often requires variability among
characters to generate dramatic tension and that sexual
165
variability can be a key weapon in the artist’s arsenal
used toward creating this tension. The latter point is also
an example of how understanding asexuality—in this
case how it plays itself out in art—provides insight
into sexuality, along with the human inclination for
170
storytelling.
Finally, Bogaert (2012b) concluded that the history
of asexuality should include mention of the emergence
of modern asexual ‘‘identities,’’ and related, the recent
visibility of individuals and groups providing infor-
175
mation and support to those who may fall under the
broad aegis of ‘‘asexual’’ (e.g., David Jay as the found-
ing member of Asexuality Visibility and Education
Network [AVEN]; Bulwa, 2009; Chevigny et al., 2011).
Definitions/Conceptualizations
180
When is someone asexual? Or, in other words, what
best defines asexuality? In the previous section on bio-
logical and historical context, I suggested that asexuality
is construable as a lack of sexual attraction or a lack of
interest in others. Thus, this definition implies a lack of
185
lustful inclinations=feelings directed toward others. This
BOGAERT
2

5. lack of sexual inclinations=feelings toward others should
be of an enduring nature or imply an enduring dispo-
sition or orientation. For example, in Bogaert (2004;
see also Bogaert, 2013), asexuality was defined as ‘‘never
190 having felt sexual attraction to others.’’ This definition
of asexuality as a lack of sexual attraction or desire
for others has partly emerged in recent years in response
to theory (e.g., Bogaert, 2006b; Chasin, 2011) and
empirical work (e.g., Bogaert, 2004; Brotto et al., 2010)
195 on asexuality, along with earlier theoretical work on
sexual orientation (e.g., Storms, 1980). This definition is
consistent with how AVEN, the most influential online
community and Web site devoted to asexuality, defines
asexuality. A consistency with AVEN’s definition does
200 not provide any particular theoretical rationale for the
use of this definition, but it is notable that it resonates
with a number of influential asexual leaders and educators
and how they view the phenomenon.
As mentioned, usage of the term asexual as a lack of
205 sexual attraction for others has partly emerged from the-
ories of sexual orientation. For example, using Storms’s
(1980) two-dimensional model of sexual orientation,
heterosexual people are defined as those individuals
having high heteroeroticism (i.e., high on other-sex
210 attraction); homosexual people are those individuals
high on homoeroticism (i.e., high on same-sex attrac-
tion); bisexual people are defined as those individuals
high on both heteroeroticism and homoeroticism; and
asexual people are those individuals who are low on
215 both heteroeroticism and homoeroticism (i.e., low on
both same-sex and other-sex attraction). Note that
Storms’s model of sexual orientation has been argued
to be an advance over Alfred Kinsey’s traditional,
one-dimensional model of sexual orientation (i.e., a
220 scale from 0¼ Exclusive heterosexuality to 6¼ Exclusive
homosexuality; Kinsey, Pomeroy, & Martin, 1948) for
a number of reasons. These reasons include the former’s
emphasis on sexual attraction=eroticism (e.g., fantasies)
over behavior, along with its ability to accommodate
225 asexuals when two dimensions are used. However, Kinsey
did recognize the existence of asexual (or nonsexual)
people and the fact that they did not conform to his
one-dimensional model of sexual orientation, calling them
‘‘Xs’’ (Kinsey et al., 1948; Kinsey, Pomeroy, Martin, &
230 Gebhard, 1953).
A definition of asexuality that centers on a lack of
sexual attraction—including sexual fantasies—to either
sex would not necessarily imply that an asexual person
would lack sexual experience with either sex, although
235 behavioral definitions of asexuality have been forwarded
(e.g., Poston & Baumle, 2010) and there is evidence of
reduced sexual behavior with others for those lacking
sexual attraction (e.g., Bogaert, 2004). Thus, a definition
of asexuality based on attraction would not necessarily
240 include those who are chaste (e.g., prior to marriage)
or celibate—those who actively eschew sex altogether—
if they are still sexually attracted to others.
A lack of sexual attraction would not necessarily
imply a self-identification as asexual, although clearly
245
many people who lack sexual attraction would also
identify as such. Note that a self-identification of asexu-
ality would be defined as a labeling of oneself as asexual,
just as self-identification of a person with same-sex
attraction would entail labeling oneself as gay or les-
250
bian, etc. Why not give precedence to self-identifications
in defining=conceptualizing asexuality? A self-
identification as asexual is important from developmen-
tal and sociocultural perspectives, which are discussed in
a later section. Many major modern professional organi-
255
zations in the social sciences and in mental health also
recognize self-identifications and argue for sensitivity
to anyone who chooses to self-identify with a sexual
orientation–relevant label (e.g., the Diagnostic and
Statistical Manual of Mental Disorders [DSM] by the
260
American Psychiatric Association [APA]). Yet a number
of issues are associated with defining asexuality merely
by a self-identification as asexual, including an inconsist-
ent awareness of a self-label(s), hesitancies in coming
out, fluctuating allegiances to a label, and political
265
motivations (e.g., Bogaert, 2012b). Similar issues often
occur, of course, in defining traditional sexual orien-
tation (e.g., gay, lesbian, queer) using self-identification
labels given the potential complexity and multidimen-
sionality of sexual identity formation in sexual minori-
270
ties (e.g., Diamond, 2003a; Seif, 1999; Vrangalova &
Savin-Williams, 2012).
Using a definition that centers on a lack of sexual
attraction would not necessarily mean asexual people
lack sexual desire. Sexual desire refers to an urge for
275
sexual stimulation (including potentially an orgasm)
and may include both partnered and nonpartnered
stimulation (e.g., masturbation). It is notable, however,
that one alternative but related definition of asexuality
is in fact a lack of sexual desire. For example, Prause and
280
Graham (2007) found evidence that many self-identified
asexual people report very low (or absence of) sexual desire.
More research needs to be conducted on the complex
relationship between attraction and desire (Bogaert,
2013; Chasin, 2011), but recent evidence and theory
285
suggest the lack of desire in asexuals may be primarily
a lack of desire for others—not lack of desire per se;
thus again, a lack of sexual attraction=desire for others
may be a defining characteristic of asexuality (see
Brotto et al. 2010; Chasin, 2011; Van Houdenhove, Gijs,
290
T’Sjoen,, & Enzlin, 2014a). In short, when there is
evidence of a form of desire in asexual people, it is often
a ‘‘solitary’’ desire—a desire that is unconnected to
others or a nonpartnered desire. For example, there is
evidence that a significant number of asexual people
295
masturbate (e.g., Bogaert, 2013; Brotto et al., 2010),
and thus asexual people may not lack all forms of sexual
desire.
Having a lack of sexual attraction would also not
necessarily mean that these asexual individuals do not
ASEXUALITY
3

6. 300 have a romantic=affectionate attraction for others.
Indeed, it is important to make a distinction between
romantic attraction (e.g., ‘‘feelings of infatuation and
emotional attachment;’’ Diamond, 2003b), and sexual
attraction [‘‘lust lure (for others)];’’ e.g., Bogaert,
305 2012b). The traditional assumption is that one implies
the other, but this is not necessarily so (e.g., Diamond,
2003b). There is evidence that, in practical terms, one’s
romantic inclinations do not always align with one’s
sexual ones: We can have romantic inclinations toward,
310 say, men, even though our primary sexual attraction
is toward women (e.g., Diamond, 2003b). Similarly,
in relationship literature, there is often a distinction
made between love and sexual=passionate love (e.g.,
Fehr, 2013). Evidence from developmental psychology
315 and evolutionary=neuroscience studies suggests that
romantic=love and sexual attraction processes are
distinct, for example, lust=sex systems having an
phylogenetically older history and primarily residing in
different brain structures than the phylogenetically
320 younger romantic=love system (e.g., Diamond, 2003b;
Fisher, 2004), which may have evolved relatively
recently from our attachment processes=systems toward
parents (e.g., Hazan & Shaver, 1987).
In line with the distinction between romantic and
325 sexual attraction, evidence suggests that asexual people
are not necessarily aromantic (e.g., Bogaert, 2004,
2006b; Carrigan, 2011; Hinderliter, 2009). For example,
although having a lower percentage than sexual people,
a significant percentage of asexual people have been
330 found to be in long-term relationships (e.g., approxi-
mately 33%; Bogaert, 2004). However, even a nontrivial
percentage of nonpartnered asexual people may still be
romantic, as a lack of long-term relationships among
many asexual people may partly reflect their (perceived)
335 inability to attract or maintain a partner who may want
a sexual relationship. Thus, some asexual people may
still have heteroromantic inclinations, others homoro-
mantic inclinations, while still others have biromantic
inclinations. Indeed, given the assumption of a close
340 alignment between romantic and sexual inclinations,
some asexual people may report their sexual orientation
as gay, straight, or bisexual based on their romantic
attractions (e.g., Bogaert, 2012b, 2013; Chasin, 2011),
insofar as the concept of a ‘‘romantic orientation’’
345 may be less familiar to people than the concept of
sexual orientation. In sum, it is important to keep in
mind that an asexual person may be romantically
inclined, despite his or her lack of sexual inclinations.
Similarly, the converse may also be true: A sexual
350 person may evince little romantic inclinations, despite
having strong sexual inclinations. This point is also
relevant to a main theme of this article (see also Bogaert,
2012b), in other words, understanding asexuality
informs our understanding of sexuality, as asexual
355 people demonstrate that romantic inclinations can be
decoupled from sexual inclinations.
Finally, the definition of asexuality as a lack of sexual
attraction (or lack of sexual desire for others) does not
necessarily imply that asexual people lack physiological
360
sexual arousal experiences. The capacity for erection
and vaginal lubrication in asexual people may be fully
intact (e.g., Brotto & Yule, 2011). For example, one
asexual person indicates: ‘‘I did, you know, test the
equipment . . . and everything works fine, pleasurable
365
and all; it’s just not actually attracted to anything’’
(Brotto et al., 2010, p. 612).
Additional Conceptual Issues
A number of other issues=considerations related to
the definition of asexuality include the following. First,
370
Bogaert (2006b) argued that ‘‘subjective’’ sexual attrac-
tion is the relevant psychological component in defining
sexual orientation, including an asexual orientation.
Subjective refers to one’s own internal or mental experi-
ence and does not necessarily include evidence of
375
physiological arousal=attraction. Often physiological
attraction is assessed by measures of physiological arou-
sal (e.g., erection, vaginal lubrication) using psychophy-
siological devices, such as the penile strain gauge and
vaginal photoplethysmograph. Note that not all sexolo-
380
gists would give precedence to subjective attraction over
physiologically based attraction in defining sexual orien-
tation (including asexual orientation), but Bogaert’s
(2006b) rationale for subjective attraction was as follows:
First, using a subjective definition of attraction seems to
385
best capture the ‘‘psychology’’ of sexual orientation
(e.g., the study of the ‘‘mind,’’ including perceptions).
Second, it may be more linked to actual sexual behavior
than physiological arousal=attraction. For example, a
person who does not perceive sexual attraction toward
390
women despite exhibiting physiological arousal patterns
toward them (e.g., in the laboratory) is unlikely to
engage in sexual behavior with these partners. Notable
in this regard is that women’s subjective sexual attrac-
tion patterns often do not match their genital arousal
395
patterns, which show arousal to female targets that is
nearly equal to arousal to male targets (Chivers, Rieger,
Latty, & Bailey, 2004). Despite this, the large majority of
these women would report their subjective sexual attrac-
tion patterns (and would identify) as heterosexual.
400
(p. 244)
Thus, genital arousal patterns are important and
informative in understanding sexuality, particularly for
men, but these patterns should not necessarily trump
subjective attraction in determining sexual orientation.
405
A related issue is whether including asexuality as
a separate and unique category of sexual orientation is
a conceptual=theoretical error, modern models of sexual
orientation notwithstanding. Bogaert (2006b, 2012b)
argued that it is not a conceptual error and that asexu-
410
ality can be construed within a sexual orientation
BOGAERT
4

7. framework. Certainly asexuality can be described as
an absence of the three main designations of sexual
orientation—heterosexual, homosexual, or bisexual—
and even as an absence of an orientation altogether,
415 given that there is little or no sex-based orienting or
directionality to their sexuality (Bogaert, 2004). How-
ever, given that (subjective) sexual attraction arguably
defines sexual orientation (e.g., Bailey, Dunne & Martin,
2000; Bogaert, 2003; Money, 1988; Storms, 1980;
420 Zucker & Bradley, 1995), or is the psychological core
of sexual orientation (e.g., Bogaert, 2003), then if one
lacks (subjective) attraction for others, asexuality is
construable as a separate, unique category within
a sexual orientation framework (Bogaert, 2006b). Thus,
425 using a model similar to Storms (1980), asexuality is
construable as the fourth category of sexual orientation,
i.e., those evincing low or no (subjective) eroticism=
attraction to either sex, or those having an ‘‘orientation’’
to neither sex (see Figure 1).
430 In sum, in this article (see also Bogaert, 2006b, 2012b)
precedence is given to subjective sexual attraction (over
physiological attraction=arousal) in defining sexual
orientation; and asexuality can be understood within
a sexual orientation framework. Thus, if an individual
435 does not subjectively experience sexual attraction—his
or her mind is not registering (or attuned to) sexual
attraction to others—regardless of his or her physio-
logical experiences, he or she can be designated as
having an ‘‘asexual’’ orientation.
440 One possible counterargument against construing
asexuality as a separate category of sexual orientation
is that asexuality may be caused by an atypical biologi-
cal process (e.g., low levels of circulating hormones,
atypical prenatal mechanisms; see section on origins);
445 and, if these biological processes were altered, then the
true sexual orientation (heterosexual, homosexual,
bisexual) of an ‘‘asexual’’ person would be revealed.
Thus, it may be argued that it is wrong, or at least
premature, to indicate that an asexual person has a
450 unique orientation that differs from the traditional three
designations. However, this reasoning may contain
a logical error, because the origins of asexuality should
not be confused with the phenomenology of asexuality.
Moreover, more broadly, we should unconfound the
455
origins from the phenomenology (or lived experience)
of sexual orientation (see Bogaert, 2006b).
As an example, if a man is attracted to other men
because of an atypical biological process—including
a biological process that is atypical for his sexual
460
orientation and that process may be alterable—does this
negate the lived experience of his (subjective) attraction
to men? In short, he no longer has (or had) same-sex
attraction; thus is not, or was not, homosexual? It is
argued here—and likely most would agree—that, no,
465
he is still homosexual because his subjective attraction
is to men, regardless of the cause of that subjective
experience, even if the cause potentially differs from
the main processes underlying homosexuality for most
individuals, and even if that process might be alterable
470
at some point in time.
Aside from these conceptual=theoretical arguments,
recent research also gives support to the idea that
asexuality is understandable within a sexual orientation
framework. Specifically, the same biological factors
475
underlying differences in traditional sexual orientation
(e.g., gay versus straight) may also underlie asexuality
(e.g., Yule, Brotto, & Gorzalka, 2014a). Moreover,
results from one small study on arousal patterns in
asexual women (n ¼ 7) are consistent with a traditional
480
sexual orientation model of asexuality, not a sexual
dysfunction one (Brotto & Yule, 2011). Thus, there is
some additional empirical evidence from research
studies—albeit with one of the studies being of small
sample size—in favor of asexuality as a separate cate-
485
gory of sexual orientation, even if one is not convinced
by these theoretical arguments.
In summary, there are a number of definitions of
asexuality, although a lack of sexual attraction (or a lack
of desire for others) is, arguably, the most common defi-
490
nition in both recent literature and among individuals
who support the most popular chat=Web site (AVEN)
devoted to asexuality issues. Also notable is that a lack
of attraction is, at least to some degree, independent of
other facets of psychosexual functioning (e.g., sexual
495
desire, sexual behavior, physiological arousal, romantic
inclinations). It should also be noted that other
definitions of asexuality (e.g., no sexual desire, self-
identifications) have been forwarded. Moreover, given
that research on asexuality is relatively recent and that
500
the phenomena of asexuality are likely diverse, it is best
to construe a lack of sexual attraction as an open defi-
nition that may fluctuate over time (Bogaert, 2012b;
see also Van Houdenhove et al., 2014b). The degree to
which the definition does change over time may have
505
interesting implications for studying asexuality’s origins,
for clinical issues, and for how we view asexuality
as a unique category of sexual orientation.
Figure 1. Model of sexual orientation based on eroticism=attraction
toward the sexes (after Storms, 1980).
ASEXUALITY
5

8. Prevalence of Asexuality
How many people are asexual? Bogaert (2012b) sum-
510 marized the available data and discussed issues related to
prevalence rates of sexual minorities, including asexual
people. Of historical interest, Kinsey reported that
1.5% of his male sample were Xs (Kinsey et al., 1948),
whereas the number of asexual women in his sample var-
515 ied depending on whether they were married or not, with
1% to 3% of women designated as Xs if they were mar-
ried, and 14% to 19% designated as Xs among unmarried
women (Kinsey et al., 1953). Kinsey’s definition of
asexuality was largely, although not exclusively, beha-
520 vioral in nature (see Poston & Baumle, 2010), which, as
mentioned, differs to some extent from most modern
definitions (e.g., a lack of sexual attraction). In addition,
most modern researchers interested in the prevalence of
sexual minorities, including asexual people, typically rely
525 on information from national probability samples,
which better represent the population than convenience
samples do. In the first study examining this issue in
a national probability sample, Bogaert (2004) found that
1% of a British national sample (National Survey of
530 Sexual Attitudes and Lifestyles [NATSAL]-I) reported
that they had ‘‘never felt sexual attraction’’ to others.
Analyzing a subsequent national sample from Britain
(NATSAL-II), albeit with a sample having a more
restricted age range than the original sample, Bogaert
535 (2013) found that 0.5% of the sample reported never hav-
ing felt sexual attraction to others (see Aicken, Mercer, &
Cassella, 2013; for a similar figure in Australia, see
Smith, Rissel, Richters, Grulich, & de Visser, 2003). In
a national cross-sectional population-based sample of
540 high school students in New Zealand, 1.8% reported no
sexual attraction to either sex (Lucassen et al., 2011).
In a recent population sample of Finnish twins, 3.3%
of the women and 1.5% of the men reported having
experienced no sexual attraction within the past year
545 (Höglund, Jern, Sandnabba, & Santtila, 2014). The latter
two studies are limited in the age range of participants
(i.e., high school students) and in the time span of inter-
est in the questioning (i.e., one year), respectively.
There are also national samples containing data on
550 low or absent desire, and usually these figures are higher
than the figures reported previously for an enduring lack
of sexual attraction (e.g., 3% to 11% in Ventegodt, 1998;
14% to 33% in Laumann, Paik, and Rosen, 1999; 7% in
Parish et al., 2003; see Bogaert, 2008). However, some of
555 these studies may have limited applicability to the ques-
tions of prevalence of asexuality (even if one assumes
a ‘‘desire’’ definition of asexuality), given that some of
these studies did not assess a total absence of sexual
desire—only ‘‘low’’ desire. Moreover, like one of the
560 studies on sexual attraction mentioned (Höglund et al.,
2014), there is no way of knowing whether those who
have a low (or absent) desire do so beyond a limited
period specified in questioning (e.g., in the past year).
Bogaert (2012b) concluded that 1% may be a reasonable
565
‘‘working figure’’ for the prevalence rate of asexuality,
but at this point we cannot be sure of an exact figure
for a number of reasons (see also Van Houdenhove
et al., 2014b). The reasons for this ambiguity include
the complication of different assessments of asexuality,
570
reflecting the fact that there is not a consensus on
a single, definitive conceptualization of the phenom-
enon. There are also sampling and recruitment issues,
even in national or probability samples. For example,
many sexual surveys, even if well conducted, may under-
575
estimate the number of asexual people, because there
may be a lack of interest=motivation for asexual people
to participate in such sexuality-based surveys (Bogaert,
2012b). Interestingly, this issue raises again a main
theme of this review paper—that studying asexual
580
people affords a better understanding of sexuality—as
a methodological weakness may occur in our studies
of sexuality, potentially affecting our understanding of
sexual people. For example, those with (temporary)
low desire and those with other sexual dysfunctions
585
may actively avoid being recruited for sexual studies
for similar reasons (see related research on volunteer
bias in sexuality studies; e.g., Bogaert, 1996; Boynton,
2003; Strassberg & Lowe, 1995).
Development and Variation
590
Identity Issues
In a number of recent publications (e.g., Bogaert,
2012b; Emens, 2014; Gressgård, 2013; Scherrer, 2008;
Van Houdenhove, Gijs, T’Sjoen, & Enzlin, 2014c)
researchers have addressed issues related to the develop-
595
ment of an asexual identity. Some periods of time
throughout history are likely to be particularly relevant
to understanding the emergence of a minority identity,
as these time periods offer individuals heightened infor-
mation about themselves, such as how similar they are
600
to other minorities and=or how distinct they are from
the majority. Certain time periods may also offer strong
challenges to, along with increased opportunities for, the
advancement of minority human rights, and thus these
time periods are relevant to understanding identity
605
formation, as identities often serve political ends aside
from psychological ones. For example, the 1970s and
1980s (e.g., Stonewall; Q1
AIDS crises) may have been
particularly important for understanding the emergence
of identities associated with same-sex attraction (e.g.,
610
coming out as gay, lesbian, queer; see Terry, 1999).
Similarly, the current period in Western society may
be particularly important in understanding the emergence
of asexual identities (Bogaert, 2012b), as an unprecedented
array of information on sexualities is available through
615
the Internet; hitherto such information has likely been
essentially invisible in all societies. It is often more difficult
BOGAERT
6

9. to recognize the absence of something, sexual or otherwise,
than it is to recognize the presence of something. Asexual
identities may also have relevance in a modern context, as
620 they offer a political rallying point against being perceived
by the public and the clinical=medical community as
having a sexual disorder, such as hypoactive sexual desire
disorder (HSDD), in the face of the modern medicalization
of sexuality (Bogaert, 2012b; see also Cacchioni & Tiefer,
625 2012).
Similar to other sexual minorities, asexual people
stand in contrast to a heterosexual majority. As such,
sexuality is the key characteristic in what makes them
different from the majority group, and hence sexuality
630 may become a very relevant ‘‘personal construct’’ for
some asexual people, even if they have never engaged
in sex (Bogaert, 2012b). In addition, asexual people
may face similar discrimination challenges to other
sexual minorities. Thus, Bogaert (2012b) speculated that
635 some identity issues and stages of development—
recognizing one’s own attractions, identifying=labeling
oneself, public disclosures or coming out, and identity
pride (e.g., Cass, 1979; Coleman, 1982; Floyd & Stein,
2002; Troiden, 1989)—theorized to occur in lesbian,
640 gay, bisexual, and transgender (LGBT) people may also
occur in the development of some asexual people’s
identity formation.
On the other hand, in contrast to other sexual mino-
rities, asexual people are, by definition, not sexual beings
645 (e.g., lacking in sexual attraction for others and=or
potentially having no sexual desire whatsoever). Thus,
for at least some asexual people, sexuality is likely
a nonissue in their lives and thus does not take center
stage when their (broader) identities are being formed.
650 Consider this quote from one asexual person discussing
identity: ‘‘Outside of AVEN or conversations specifi-
cally about sexuality, I don’t really consciously think
of myself as asexual. Like being an atheist or non-
Hispanic or a non-driver (all apply), asexuality is some-
655 thing I’m not and never was, rather than something I am.
The label is mostly a useful marker. So, my asexual
identity is important in certain contexts, and I can’t
imagine my life if I weren’t asexual, but it is not specifi-
cally important to me’’ (Scherrer, 2008, p. 630).
660 Discrimination
A number of publications have addressed discrimi-
nation toward asexual people (e.g., Bogaert, 2012b;
Emens, 2014; MacInnis & Hodson, 2012). On one hand,
it may be the case that asexuals—as a relatively invisible
665 minority—may be assumed to be less at risk for overt
discrimination than other, more visible sexual minorities
(see Bogaert, 2012b for a discussion). On the other hand,
there is evidence that asexual people may suffer similar
challenges to other sexual minorities (see Scherrer,
670 2008). There may also be unique facets to asexuality that
bring special and intensified forms of discrimination. At
a structural level, there is evidence that many societies’
legal systems privilege sexual over asexual people
(Emens, 2014; Gressgård, 2013). For example, those in
675
conjugal partnerships (e.g., marriages) often have
additional rights and benefits over single individuals or
those in nonsexual partnerships. Although not all asex-
ual people are single and, of course, not all single people
are asexual, there is evidence that asexual people are less
680
likely to have had a long-term relationship than sexual
people (e.g., Bogaert, 2004); thus, this form of structural
discrimination against nonconjugal people may have
a heightened relevance to asexual people. On an indivi-
dual, psychological level, MacInnis and Hodson (2012)
685
found evidence that heterosexual people often view
asexual people with more disfavor than other sexual
minorities (e.g., gays, lesbians) and may characterize
them as ‘‘less than human.’’ The MacInnis and Hodson
study again illustrates how the study of asexuality helps
690
us to better understand sexuality, in particular how sex
influences prejudice along with, more broadly, how
people perceive the nature=essence of humanity.
MacInnis and Hodson (2012) write: ‘‘Sexuality appears
to be perceived as a key component of humanness.
695
The dehumanization measures employed did not
explicitly reference sexuality, yet asexuals were strongly
biased against on these measures. Thus, characteristics=
emotions representing humanness are clearly inter-
twined with sexuality and=or sexual desire’’ (p. 734).
700
Variation
Masturbation is an important activity in a number
of ways for understanding the significant variation that
likely exists among asexual people (Bogaert, 2012a,
2012b). For one, variability in masturbation demon-
705
strates that not all asexual people exhibit a complete
absence of activities construable as sexual. For example,
a significant number of asexual people masturbate
(e.g., Bogaert 2013; Brotto et al., 2010), although the
evidence, particularly data from a national sample, sug-
710
gests it is at a lower level than sexual people (Bogaert,
2013). The lower rate of masturbation among asexual
people relative to sexual people suggests that many asex-
ual people may find masturbation less intensely reward-
ing and pleasurable than sexual people. For example,
715
masturbation is less likely to occur at a high frequency
when it is not accompanied by intensely rewarding,
pleasurable feelings (e.g., Clifford, 1978). Indeed, when
masturbation occurs among some asexual people, this
activity may merely serve an utilitarian=health function.
720
In a study that included interviews and qualitative
analyses, one asexual person reported that masturbation
was used to ‘‘clean out the plumbing’’ (Brotto et al.,
2010, p. 611). However, the finding that a significant
number of asexual people masturbate is also consistent
725
with the notion that some asexual people may contain
a non-partner-oriented (or nondirected) sexual desire.
ASEXUALITY
7

10. In other words, for some asexual people, there may be
lustful feelings=sensations that are ‘‘diffuse’’ and with
no direction toward, or connection to, others. Finally,
730 and related to this last point, these findings reinforce
the need to be sensitive to different definitions of asexu-
ality (e.g., some who evince some solitary, nondirected
desire and some without desire altogether), although,
as mentioned, both of these variations may be compat-
735 ible with a definition of a lack of sexual desire for (or
attraction to) others, at least at some basic sexual level.
Masturbation in asexual people, particularly if in
conjunction with sexual fantasies (see Brotto et al.,
2010; Yule, Brotto, & Gorzalka, 2014b), also raises
740 questions about the possibility of some asexual people
having a paraphilia, an unusual sexual attraction
(Bogaert, 2008, 2012a, 2012b). Bogaert (2012a, 2012b)
suggested that some asexual people may have a
‘‘target-oriented’’ paraphilia, in which there is an inver-
745 sion, reversal, or disconnection between the self and the
typical target=object of sexual interest=attraction (e.g.,
Blanchard, 1991). For example, some asexual people
may be attracted to themselves, called automono-
sexualism (Bogaert, 2008), in which the target of their
750 sexual attractions may be turned inward onto them-
selves. A variation on automonosexualism occurs in
the phenomenon of autogynephilia, a target-oriented
paraphilia in which a man is sexually attracted to him-
self but as a woman (e.g., Blanchard, 1989; Lawrence,
755 2011). Some asexual people may have similar paraphi-
lias in that they themselves, or their identities, are dis-
connected from their sexuality; in other words, there is
no identity or ‘‘self’’ or ‘‘I’’ involved with their sexual
expressions (e.g., in their fantasies). This disconnect
760 between the ‘‘self’’ and a sexual target=object has
been termed autochorissexualism (Bogaert, 2012a). For
example, an asexual person writes this about his mastur-
batory fantasies on AVEN: ‘‘I almost invariably think
of fictional characters. My thoughts have never involved
765 people I know, and they have never involved myself’’
(Vicious Trollop, 2005). Similarly, another AVEN
participant writes: ‘‘It’s scenes in the third person;
I may have a generic male character which is kind of
me, but it’s still separate from me, mentally watched
770 rather than participated in’’ (Teddy Miller, 2005).
If these individuals have, arguably, some form of
sexual attraction to others, for example, by generating
sexual stimuli (e.g., fantasy) that contain other people
or perhaps view sexual imagery of people in pornogra-
775 phy, then it raises a question about whether these indivi-
duals do have a (traditional) sexual orientation—
whether they are ‘‘sexual’’ with an inclination toward
others and thus are not ‘‘asexual’’ as defined as lack
of sexual attraction (to others). As Bogaert (2012b; see
780 also Bogaert, 2008) suggested, this is an interesting
conceptual=definitional issue in sexuality, particularly
in understanding what is and what is not a sexual
orientation. Bogaert (2012b) also suggested, however,
there is an argument in favor of construing such indivi-
785
duals as asexual (including a lack of sexual orientation
to others), because they still lack a form of ‘‘subjective’’
attractiveness (to others), given that the ‘‘I’’ or ‘‘self’’ is
missing from their sexuality. In other words, there is no
‘‘self’’ sexually connected to others, even though there
790
may be some level of physical response (and some level
of brain regulation) responding to sexual stimulation.
Bogaert (2012b) concluded that more research needs
to be conducted on this potential sexual ‘‘disconnect’’
between the self and others in some asexual people,
795
including examining additional content in their sexual
fantasies (if they exist) or in their use of pornography,
along with their physiological arousal behavior.
Understanding identity-less sexuality in asexual
people may help illuminate typical processes in sexual
800
people. Thus, it reveals what is implicit in most sexual
expressions, in other words, that sexual individuals
usually have a ‘‘self’’ engaged in and connected to their
sexual objects=targets. In one’s sexual fantasies, for
example, sexual individuals usually assume the role of
805
a protagonist in engaging in sexual behavior with others.
Thus, although people’s fantasies may vary in the degree
to which the protagonist is proceptive (initiating=directing
the action) or receptive (responding to other’s actions)
and, related, whether the protagonist views others or
810
presents himself or herself as an ‘‘object of desire’’
(e.g., Bogaert, Visser, & Pozzebon, 2015), there still is
usually a ‘‘self’’ (or ‘‘I’’) as the protagonist in people’s
sexual fantasies. Yet as the fantasies mentioned suggest,
some asexual people evidently do not have this ‘‘I’’
815
connected to their sexuality.
Second, understanding identity-less sexuality puts
into relief other identity-related phenomena that charac-
terize human sexuality. For example, in many hetero-
sexual men’s sexual targeting of women, there is an
820
objectification where men may visualize female bodies
or parts of their bodies without a face or any semblance
of a personality; and thus their sexual targets can be
perceived to be devoid of any discernable identity.
Thus, identity issues are very relevant and worthy of
825
understanding in both the subject (e.g., ‘‘I’’ or ‘‘self’’
as a protagonist) in sexual activities, including fantasies,
and in the perception of the object=targets in human
sexual expressions. Much still needs to be understood
about how the self operates within sexual expressions,
830
and the study of asexuality may help illuminate these
processes.
There is also notable variation in asexuality based on
gender. For one, there is evidence more women than
men are asexual (e.g., Bogaert, 2004, 2013; Höglund
835
et al., 2014; Brotto et al., 2010). For example, Bogaert
(2004) found that approximately 70% of the asexual
people in NATSAL-I, were women (i.e., reported never
experiencing sexual attraction to others). In several
publications Bogaert (2004, 2012b, 2013) raised a
840
number of possibilities for why this gender difference
BOGAERT
8

11. in asexuality occurs. One of these possibilities was
related to masturbation. Men masturbate more than
women do, particularly during adolescence (e.g.,
Petersen & Hyde, 2010). Such self-stimulation may be
845 construed, at least partially, as ‘‘learning=conditioning’’
trials leading to enduring sexual attractions to others
(e.g., Bogaert, 2012b). If people of a particular gender
are regularly the object of one’s desire in fantasies
(e.g., self-induced imagery or imagery in viewed
850 pornography) during masturbation, then people of that
gender may become part of one’s permanent sexual
attractions. If so, in some women who do not mastur-
bate, or do so very rarely, there may be little develop-
ment of strong sexual attractions.
855 Another possibility is related to women’s sexuality,
relative to men’s, being more flexible, responsive, and
open to social=cultural influences (e.g., Baumeister,
2000). If so, women may have an increased likelihood
to developing asexuality if life circumstances are
860 atypical or perhaps not conducive to traditional
sexualization. An additional related consideration
includes the possibility that women are less socialized
to be sexual beings and=or have more atypical sexual
socialization experiences relative to men (e.g., Aubrey,
865 2004; Oliver & Hyde, 1993; Petersen & Hyde, 2010),
and thus an absence of sex (e.g., lacking in sexual
attractions to others) may be compatible with how
they describe their inclinations and their overall sense
of (sexual) selves.
870 In a number of publications Bogaert (2004, 2006b,
2012b) argued that our conceptualization and measure-
ment of sexual orientation might also play a role in
finding a gender difference in asexuality. As sexologists,
we have traditionally viewed sexual orientation in
875 a ‘‘target-oriented’’ way, in other words, people’s sexual
orientation is construed as being directed sexually
toward or to others, either men or women, or both if
bisexual. Our questions assessing sexual orientation also
imply this target-oriented view of sexual orientation.
880 For example, consider the often-used sexual orientation
question: ‘‘To whom are you sexually attracted?’’ This
type of question implies a ‘‘target’’ group of individuals
(men, women, or both) to whom we direct sexual inter-
ests. This question assumes our sexuality is inherently
885 directed toward others. However, such a conceptualiza-
tion may be unduly influenced by a male model of sexu-
ality, because men are usually more category specific in
their arousal (e.g., Chivers et al., 2004) and are more
proceptive (versus responsive) and objectifying in their
890 sexuality (e.g., Basson, 2002; Baumeister, 2000; Bogaert
& Brotto, 2014; Diamond, 2003b; Meana, 2010; Wallen,
1995) relative to women. Thus, men are, arguably, more
target oriented in their sexuality (e.g., Bogaert, 2004,
2012b, 2013) than women are. If so, traditional,
895 target-oriented questions of sexual orientation may not
resonate with some women and their subjective experi-
ence of sexuality. As a consequence, some of these
women may report not being sexually attracted to others
(hence asexual).
900
A second gender-related variation concerns gender
roles=identities. It is clear that some sexual
minorities—for example, gay and lesbians—on average
do not conform to traditional gender roles (e.g., Rieger,
Linsenmeier, Gygax, & Bailey, 2008). It is unclear, how-
905
ever, whether asexual men and women on average also
do not conform to traditional gender roles. For
example, to the author’s knowledge there is no research
examining how asexual people score on traditional mea-
sures of gender roles. Bogaert (2012b) did speculate that
910
asexual people are likely untraditional in some aspects
of gender roles, in part because sexual development
may make boys and men more traditionally masculine
and girls and women more traditionally feminine (see
Hundhammer & Mussweiler, 2012). In addition, there
915
is some evidence that an elevated percentage of asexual
people do not identify as either male or female, thus
having a nontraditional gender identity (Brotto et al.,
2010; Gazzola & Morrison, 2012). For example,
approximately 13% of the asexual people studied in
920
Brotto and colleagues’ (2010) research did not identify
as male or female. These figures reinforce a main idea
forwarded in this section on variability that asexual
people likely form a very diverse group—in other words,
‘‘one size does not fit all’’—but also that one of the
925
important variations may run along basic gender
identity lines.
There is also some noteworthy evidence that asexual
men and women may share some aspects of sexual func-
tioning with sexual individuals of their same gender. For
930
example, using psychophysiological measures of sexual
arousal, self-identified asexual women have been found
to evince patterns of arousal similar to other women;
in other words, they are non–category specific in their
response (see Brotto & Yule, 2011). To date, there is
935
no published research on patterns of psychophysiologi-
cal sexual arousal in asexual men. Similarly, evidence
suggests that both asexual men and women share some
patterns of masturbation with their biological sex
(men > women), with asexual men having an elevated
940
frequency of masturbation relative to asexual women
(e.g., Bogaert, 2013; Brotto et al., 2010). The fact that
asexual men masturbate more than asexual women sug-
gests that paraphilias—to the degree that they exist in
asexual people (e.g., Bogaert, 2012a)—may be elevated
945
among asexual men relative to asexual women. Such a
conclusion may be warranted for two reasons. First,
the content of one’s masturbatory fantasies is related to
one’s sexual attractions=inclinations (e.g., MacCulloch,
Snowden, Wood, & Mills, 1983; Storms, 1980). As such,
950
asexual men’s elevated rate of masturbation, some of
which is accompanied by fantasy (Yule et al., 2014b),
is not likely of typical content, given that asexual
people do not exhibit sexual attractions to people. Thus,
asexual men may have elevated paraphilic attractions
ASEXUALITY
9

12. 955 relative to asexual women, given that they masturbate
more than do asexual women, and such masturbation
may, at times, be accompanied by atypical fantasies.
Second, this conclusion is consistent with evidence that
men exceed women in the incidence of paraphilias
960 (Cantor, Blanchard, & Barbaree, 2009). However, an
increased incidence of paraphilias among asexual men
relative to asexual women remains a speculation, as
limited research exists on the content of sexual fantasies
(Yule et al., 2014b), along with other evidence of
965 unusual attractions, in asexual people.
As a final note in this section, a theme in this article
is, as mentioned, that understanding asexuality helps
us understand sexuality, and this is certainly true
in the context of gender differences in sexuality. For
970 example, we may understand better how women’s
sexuality, relative to men’s, may be less target oriented,
which may have implications for a number of aspects of
sociosexual functioning, including women’s reporting of
sexual attraction (or their lack of attraction) to others.
975 Origins
A number of research studies have addressed the
origins of human asexuality. One line of research focuses
on markers=correlates of early biological development,
similar to work on traditional sexual orientation
980 (e.g., LeVay, 2010; Wilson & Rahman, 2005). Bogaert
(2004, 2013) found evidence that asexual men and
women have, on average, a shorter stature than sexual
people. Bogaert (2004, 2013) also found evidence that
asexual women have, on average, atypical menstrual char-
985 acteristics relative to sexual women (see Ingudomnukul,
Baron-Cohen, Wheelwright, & Knickmeyer, 2007). These
correlates are suggestive of early biological influences
on asexuality, as both are potential markers of early
biological determinants, including prenatal factors
990 (e.g., Bogaert & Liu, 2013; but see Bogaert & McCreary,
2011). Yule and colleagues (2014a) found evidence
that non-right-handedness in both men and women
and the number of older brothers in men are associated
with asexuality. Handedness is particularly relevant to
995 explanations of early biological determinants in asexual
development, because it is a clear marker of prenatal
development (e.g., Hepper, Shahidullah, & White,
1991). Handedness patterns have also been linked to
other nonheterosexual sexual orientations and other
1000 sexual inclinations (e.g., Bogaert, 2001; Lalumière,
Blanchard, & Zucker, 2000), suggesting that asexuality
shares a common origin with these other sexual
orientations=inclinations. An elevated number of older
brothers may also be relevant to prenatal influences on
1005 sexual orientation development, as it has been linked
to homosexuality in men (e.g., Blanchard & Bogaert,
1996) and this linkage is likely the result of prenatal
influences (Bogaert, 2006a). The most well-articulated
prenatal explanation of the ‘‘older brother’’ (or ‘‘fraternal
1010
birth order’’) effect is the maternal immune hypothesis,
where a mother develops an immune response against
a male-specific protein important in brain development
after being exposed to one or more male pregnancies
(Blanchard & Bogaert, 1996; Blanchard, 2004; Bogaert
1015
& Skorska, 2011).
The biological research on low desire issues—such as
evidence of low circulating testosterone (e.g., Bolour &
Braunstein, 2005; Riley & Riley, 2000)—may be relevant
as well, if we are to define asexuality broadly and to
1020
include instances where individuals evince no or very
low desire (e.g., Prause & Graham, 2007), or if such con-
ditions ultimately contribute to a lack of (subjective)
sexual attraction and=or to an asexual identity in some
people. There is also some evidence that at least some
1025
asexual people (i.e., those who report no sexual attrac-
tion for others) have elevated physical health issues
(Bogaert, 2004, 2013), with some conditions potentially
impacting adult testosterone levels. On the other hand,
to the author’s knowledge, there is no direct research
1030
on those individuals who report a lack of sexual
attraction for others, or self-identified asexuals, having
lower levels of testosterone. In addition, assuming that
animal models are applicable to understanding human
asexuality, there is no or little evidence that ‘‘asexual’’
1035
(noncopulating) rodents differ from sexual ones in their
testosterone levels (e.g., Alexander, Stellflug, Rose,
Fitzgerald, & Moss, 1999). Moreover, as mentioned,
there is evidence that many asexual people still exhibit
solitary desire and masturbate (e.g., Bogaert, 2013;
1040
Brotto et al., 2010); thus, altered testosterone levels
may not be applicable in most cases.
Interestingly, some qualitative research on asexual
women (Van Houdenhove et al., 2014c) suggests that
a high percentage of asexual people may have ‘‘always
1045
felt different,’’ similar to the often-reported sense among
many gays and lesbians of always ‘‘being different’’
from the heterosexual majority (see Sage, 2013; Wilson
& Rahman, 2005). Such reflections suggest, although
they do not demonstrate, that the origins of asexuality,
1050
like other enduring sexual orientations, may reflect in
part very early influences, including potential prenatal
ones.
Bogaert (2012b) also speculated that some psychoso-
cial factors might be relevant, including atypical or
1055
extreme environmental conditions, such as early sexual
trauma. Such early sexual influences have been argued
to play some role in other atypical sexual inclinations
of an enduring nature (e.g., Seto, 2008). However, there
is little evidence that self-identified asexuals are moti-
1060
vated by avoidance=aversion issues (Prause & Graham,
2007), assuming, for example, that sexual trauma is
sometimes linked to avoidance=aversion issues. It is also
important to note that no research to date has examined
the impact of such environmental influences on
1065
asexuality directly, although there is some evidence that
broad societal or macrolevel environmental variables
BOGAERT
10

13. (e.g., lower socioeconomic status and education, higher
religiosity) may be correlated with asexuality (e.g.,
Bogaert, 2004). Assuming such influences do play a role
1070 in some forms of asexuality, again some sensitivity to
variability and different patterns of expression of
asexuality is warranted, as some asexual people may
be more ‘‘hardwired’’ while others may reflect respon-
sivity to certain strong environmental factors. If there
1075 are different ‘‘forms’’ of asexuality based on origins,
does this mean that the potential ‘‘hardwired’’ form is
the ‘‘real’’ form of asexuality while the more responsive
form is an ‘‘unreal’’ type? As suggested, the perspective
taken in this article (also Bogaert, 2006b, 2012b) is that
1080 such distinctions are dubious. It is necessary to uncon-
found the origins of asexuality from both the phenom-
enology of asexuality as an orientation and, relatedly,
with whether it may be construed as a disorder. Thus—
again using homosexuality as an example—if two people
1085 have an enduring subjective sexual attraction toward
the same sex, yet the origins of that subjective attraction
differ for these individuals, it does not negate the
‘‘realness’’ (or phenomenology) of their orientation as
homosexual for either one of them.
1090 Prause and Graham (2007) found evidence that
self-identified asexuals have lower sexual ‘‘excitatory’’
processes but not necessarily higher ‘‘inhibitory’’ ones.
Bancroft, Graham, Janssen, and Sanders (2009) have
argued in their dual control model that sexual function-
1095 ing is influenced by both excitatory (high) and inhibitory
(low) mechanisms. Thus, from a developmental perspec-
tive, processes related to lower excitatory (versus higher
inhibitory ones) may be particularly relevant to under-
standing asexuality. Both excitatory and inhibitory
1100 processes are likely influenced by multiple factors,
including biological and sociocultural ones. As such,
Prause and Graham’s (2007) research, although not
isolating a specific causal factor underlying asexuality
per se, may provide some direction for specific causal
1105 factors within a broad model of sexual functioning.
Bogaert (2012b) argued that understanding gender
differences in asexuality may also offer clues to under-
standing the origins of asexuality. Potential causal
explanations were raised in the gender section in this
1110 article, but here two more are discussed. As mentioned,
there is some evidence that an elevated percentage of
asexual people eschew identifying as either male or
female (e.g., Brotto et al. 2010). There is also evidence
of a somewhat higher rate of asexuality among trans-
1115 gender individuals (4%; Grant et al., 2011) relative to
the rate of asexuality in general populations (e.g., 1%,
Bogaert, 2004). From a biological perspective, these
findings suggest there may be both demasculinizing
and defeminizing prenatal mechanisms (e.g., alteration
1120 of hormones, male- and female-specific proteins) operat-
ing in some asexual individuals; and as a consequence
these mechanisms also ‘‘desexualize’’ the individual.
Implicit in this perspective is that biological processes
related to sexual differentiation not only create biological
1125
sex=gender but also underlie sexual orientation and,
ultimately, sexualize the individual (e.g., Bao & Swaab,
2011; Breedlove, 2010). From a psychosocial perspec-
tive, there may be socializing factors related to gender
that may make individuals more or less sexualized.
1130
For example, Bogaert (2012b) speculated that not
identifying with one or both of the two traditional
genders may reduce traditional sexualization, given that
gender roles contain sexual expectations that girls and
boys may internalize.
1135
Medical/Clinical Issues
Asexuality and Its Relation to Sexual Problems/
Disorders
What is the similarity between asexuality and various
forms of diagnosable sexual dysfunctions, such as
1140
HSDD as defined by the DSM-IV and the DSM-5, or
female sexual interest=arousal disorder (FSIAD) as
defined in the DSM-5? HSDD is defined by the DSM-
IV-TR as ‘‘persistently or recurrently deficient (or
absent) sexual fantasies and desire for sexual activity’’
1145
(American Psychiatric Association, 2000, p. 539). Note
HSDD, still diagnosable in men, no longer exists for
women in the DSM-5, but similar criteria for sexual
interest issues exist for FSIAD in the DSM-5. For
example, one of FSIAD’s criteria is ‘‘Absent=reduced
1150
interest in sexual activity’’; another is ‘‘Absent=reduced
sexual=erotic thoughts or fantasies.’’ A clinician must
make the judgment of what entails a reduced or absent
interest. A diagnosis also includes a symptom duration
of at least six months.
1155
Both HSDD and FSIAD can be divided into certain
subcategories or specifications, such as generalized ver-
sus situational and lifelong versus acquired. For HSDD
and related FSIAD variations=disorders, a diagnosis is
only applied if the patient=client is in distress. Certain
1160
medical conditions, along with depression and the use
of certain drugs known to lower sexual desire are
excluded from a main diagnosis of HSDD or FSAID.
Thus, if such conditions fully explain the low=absent
desire, a separate diagnosis is applied (e.g., FSIAD or
1165
HSDD due to major depressive disorder).
Notably, in contrast to previous DSM editions, the
wording in the DSM-5 now allows for someone to
‘‘self-identify’’ as asexual and thus not be diagnosed as
having lifelong HSDD or FSAID (e.g., ‘‘If a lifelong
1170
lack of sexual desire is explained by self-identification
as ‘asexual,’ then a diagnosis of female sexual interest=
arousal disorder would not be made’’ (American
Psychiatric Association, 2013, p. 434). Some recent
literature on theoretical issues (Bogaert, 2006b),
1175
research on distress in self-identified asexual people
(e.g., Brotto et al., 2010; Prause & Graham, 2007), as
ASEXUALITY
11

14. well as the work of asexual activists (e.g., Bulwa, 2009;
Hinderliter, 2013; Brotto, 2010), were likely influential
in the decision to add this provision to the DSM-5.
1180 Given the DSM-5’s recent exclusion criteria on
self-identification as an asexual, does there remain any
overlap between asexuality, as defined previously (e.g.,
as a lack of sexual attraction or a lack of desire for
others), and HSDD=FSAID and related diagnoses?
1185 There is indeed still potential overlap between asexuality
and forms=variations of HSDD=FSAID, at least on
a theoretical level (Bogaert, 2006b, 2012b; Flore, 2013;
Hinderliter, 2013). For example, people who have had
a lifelong absence of sexual thoughts=fantasies and=or
1190 sexual desire and are markedly distressed about this
situation (lifelong SIAD or HSDD) would not likely
have had any sexual attraction to (or desire for) others.
Thus, these individuals may be construable as asexual,
even if, for example, at this point in their lives they
1195 may not self-label or identify as such. In short, the
overlap or similarity between asexuality and a lifelong
HSDD and FSIAD (and related conditions) is notable,
at least theoretically.
On the other hand, there are also important differ-
1200 ences between some forms of asexuality and FSAID=
HSDD (along with related disorders). First, it is impor-
tant to remember that most forms of HSDD=FSIAD
are not necessarily lifelong in duration. As asexuality
is an enduring (e.g., lifelong) lack of sexual attraction
1205 or desire for others, it may not overlap with the most
frequently diagnosed forms of HSDD and FSIAD.
Second, it is important to remember that additional
conditions=criteria (e.g., marked distress) must occur
before a diagnosis of HSDD=FSIAD is established. If
1210 so, likely many people who have enduring lack of sexual
thoughts=fantasies and=or sexual desire (and hence are
asexual) would not be diagnosable with HSDD=FSIAD
because they are not distressed.
In summary, there is some theoretical overlap
1215 between lifelong HSDD and FSIAD and asexuality,
and some asexuals, broadly defined (e.g., lifelong lack
of sex attraction; lifelong lack of desire for others)
may still be diagnosed if, for example, they exhibit dis-
tress, while others (e.g., who have no distress or who
1220 self-identify) would not. Part of this overlap may cause
some confusion among clinicians as to when a diagnosis
of HSDD=FSIAD should apply—a confusion that
stems in part from a largely research-based definition
of asexuality that is centered on a lack of sexual attrac-
1225 tion to others while the DSM-5 largely focuses on
desires (e.g., HSDD) and an exclusion criterion based
on self-identification.
Is Asexuality a Disorder?
A broader but related issue is this: Should asexuality
1230 be viewed as a pathology or a disorder that needs cor-
recting? For example, was the DSM-5 committee wrong
in adding language to allow self-identified asexuals to not
be diagnosed as having a sexual problem? Conversely,
has the DSM not gone far enough, and thus should
1235
there be a full depathologizing of asexuality, as occurred
for homosexuality in 1973 in the DSM-II? In a series of
publications Bogaert (2006b, 2008, 2012b) addressed
empirical research and theoretical issues on whether
asexuality should be construable as a pathological state.
1240
He concluded that asexuality, per se, should not be
construed as a pathology. Some of the evidence and
arguments consistent with this perspective are given here
(see Bogaert, 2012b, for additional arguments).
One argument against pathologizing asexuality was
1245
that although only a small portion of the population is
asexual, statistical rarity, at least by itself, is a poor basis
for pathologizing a condition or variation. For example,
other sexual variations are also rare, but individuals
having these variations (e.g., gays and lesbians) are not
1250
construed as pathological merely because of their
minority status. Also, it is important to recognize that
statistically rare conditions in various domains of life
are, at least at times, valued and life-enhancing (e.g.,
exceptional musical talent).
1255
Another issue raised was whether distress and
other mental health issues in people lacking sexual
attraction=desire should be used to determine pathol-
ogy. As mentioned, most modern medical and psycho-
logical approaches, including those informing the
1260
diagnostic criteria in the DSM-5, often limit sexual
pathology=dysfunction (and the need for treatment)
to when these inclinations entail distress. Although
more research is needed, there is some evidence that
self-identified asexual people are not significantly
1265
distressed by their lack of sexual interest=attractions
per se (Brotto et al., 2010; Prause & Graham, 2007).
Some research has also addressed whether asexual
people have other mental health and interpersonal
problems. There is evidence that certain mental health
1270
issues, such as depression, anxiety, and interpersonal
problems, are elevated in asexual people relative to other
groups (Yule, Brotto, & Gorzalka, 2013; Brotto et al.,
2010). There is also some evidence of elevated rates
of asexuality among individuals with autism spectrum
1275
conditions (Gilmour, Schalomon, & Smith, 2012;
Ingudomnukul et al., 2007). However, it is also impor-
tant to note that elevated rates of mental health issues
in asexual people do not necessarily mean that all (or
even a majority) of asexual people have these issues.
1280
For example, the significant effects associated with
group differences in Yule and colleagues’ (2013) study
were typically small in terms of effect size. Research
on mental health issues in other sexual minorities is also
worthy of considering in this context. Lesbians, gays,
1285
and bisexuals have been found to have elevated mental
health issues, including sometimes experiencing distress
about their sexual orientation (e.g., Meyer, 2003). How-
ever, it is also true that many individuals with same-sex
BOGAERT
12

15. attraction have mental health within the normal range
1290 (e.g., Busseri, Willoughby, Chalmers, & Bogaert, 2006).
Moreover, modern medicine and clinical psychology
excludes homosexuality as a diagnosable disorder and
thus does not view homosexuality as pathological.
Similarly, even though mental health issues seem to
1295 occur in asexual people at an elevated rate, this does
not necessarily mean that we should use this information
to pathologize asexuality, generally speaking.
Also, the distress and mental health issues in sexual
minorities have an additional complication. Should we
1300 pathologize someone for feeling distressed (or having
other mental health issues) if it is a response to a society
that does not value them—and, indeed, may actively dis-
criminate against them? In other words, it is important
to consider the sources of the distress and mental health
1305 issues in sexual minorities. Distress and other mental
health issues may be very understandable (and even
rational) responses to a society that discriminates
against and devalues these individuals (Bogaert, 2012b;
Yule et al., 2013).
1310 An additional consideration is associated with the
origins of asexuality. If atypical prenatal development
(along with physical health considerations) underlies at
least some forms of asexuality (e.g., Bogaert, 2004; Yule
et al., 2014a), should such a linkage imply that asexu-
1315 ality is a pathology? Such associations are, of course,
important for understanding the origins of asexuality,
but it is also important to keep in mind a number of
qualifications relevant to this linkage. First, these
markers of physical health and atypical prenatal devel-
1320 opment, at least currently, account for only a modest
amount of variation in asexuality. Thus, even if research
demonstrates that a percentage of asexual people have,
for example, serious health problems, this does not
imply that all asexual people, or that asexuality per se
1325 should be pathologized. Second, and perhaps more
important, using a research finding that an unusual pre-
natal event is (causally) associated with a trait to imply
that someone with that trait currently has a disorder is
problematic. Again, research on other sexual minorities
1330 is worthy of considering in this context. For example,
there is evidence that unusual prenatal events—such as
developmental instability; maternal immune response,
maternal stress (e.g., Blanchard, 2004; Bogaert &
Skorska, 2011; Ellis & Cole-Harding, 2001; Lalumière
1335 et al., 2000)—may play a causal role in same-sex attrac-
tion, and yet we currently do not pathologize homo-
sexuality. In addition, returning to another example
mentioned previously, it is possible that some forms of
high musical talent are determined by unusual prenatal
1340 events (e.g., higher-than-typical exposure to testoster-
one; Manning, 2002), yet we do not pathologize high
musical ability. In short, it is important to caution
against confounding origins, atypical or otherwise, with
an understanding of what is construable as a current
1345 pathological state (Bogaert, 2006b, 2012b).
In addition, existing psychophysiological research
does not support the notion that asexual women have
what would be currently construable as a diagnosable
physical arousal disorder. For instance, Brotto and
1350
Yule’s (2011) research indicates that self-identified asex-
ual women have similar arousal responses to sexually
functional women (i.e., non-category-specific arousal).
Based on these findings, the authors suggest asexuality
should not necessarily be construed as a (physical
1355
arousal) disorder, as asexual women do not evince
abnormally low arousal responses. Instead, as men-
tioned, these authors suggest the patterns of arousal
responses in their data are consistent with a sexual
orientation model of asexuality in women. As a caution-
1360
ary note, to date there are no published data on the
psychophysiological arousal patterns of asexual men
and, as mentioned, Brotto and Yule’s (2011) study,
although interesting, contained only a small sample of
asexual women (n ¼ 7).
1365
As an additional argument against pathologizing
asexuality, Bogaert (2012b) suggested that, in a thought
experiment, if we view broadly and ‘‘deconstruct’’ sexu-
ality, it can be viewed as a debilitating behavior with
odd, even bizarre, rituals and movements. Bogaert
1370
(2012b) also provided evidence that sexuality is often
associated with extreme and risky behaviors along
with impaired cognitive functioning. Bogaert (2012b)
concluded that sexuality is construable as a form of
‘‘madness’’ (broadly defined). Bogaert also concluded
1375
that, although sexuality is often a source of intense pas-
sion and pleasure and a ‘‘condition’’ most sexual people
suffer from gladly, it should give us pause about what is
and what is not a disorder.
Why Asexuality Should Matter to Sexologists
1380
Why should the absence of sexuality be of interest to
sexologists, those scholars devoted to studying sexuality,
construable as the polar opposite of asexuality? For one,
it allows us to understand an understudied sexual
minority. In recent years, research on asexuality has
1385
increased (e.g., Przybylo, 2013), but asexual people are
still not well understood as a minority on the sexuality
spectrum. Related, asexual people highlight the broad
range of this spectrum and, more fundamentally, the
nature and extent of human variability of which both
1390
sexual and asexual people belong. Finally, and perhaps
equally as important for sexologists, is that under-
standing asexuality can increase our understanding of
sexuality. This idea is discussed in the following sections.
Through the Lens of Asexuality
1395
In the same way that studying homosexuality allows
us to examine and potentially better understand hetero-
sexuality and vice versa, the study of asexuality allows
ASEXUALITY
13

16. for a broader view and, potentially, a deeper under-
standing of sexuality. Examples were given throughout
1400 this review paper, and this conclusion—of providing a
deeper understanding of sexuality—should be seen as a
main theme throughout. One example was that studying
asexuality can provide insight into the difference
between romance and sexuality, for example, asexual
1405 people demonstrating that these processes are poten-
tially de-coupleable. It was also suggested that studying
asexuality allows for a better understanding of metho-
dological weaknesses present in the study of sexuality,
such as volunteer bias. Moreover, studying asexuality
1410 reveals insight into gender differences in sexual function-
ing: how, for example, an (implicit) target-oriented view
of sexuality and sexual orientation in particular—as an
attraction to something—may not apply as directly to
women as it does to men. It was also suggested that
1415 literature and other forms of dramatic arts=media often
require variability in characters to generate dramatic
tension and that use of sexual variability in charac-
ter—including ones with an asexual aura—is a literary
technique of creating this tension. Thus, how asexuality
1420 plays itself out in art provides insight into sexuality
and, more broadly, human nature. In addition, it was
suggested that prejudicial views against asexual
people—viewing them as ‘‘less than human’’—indicate
that sexuality is a key element that humans use (perhaps
1425 implicitly) to understand what comprises the nature
of being human. It was also suggested that studying
asexuality and considering whether it should be
construed as a disorder may reveal the strangeness (even
the ‘‘madness’’) of sex.
1430 Beyond the examples presented throughout this
article, Bogaert (2012b) also suggested that studying
asexuality—for example, taking an asexual person’s
perspective, to the degree that such a view is possible
for a sexual person—reveals how sex is deeply embed-
1435 ded in our worldview=culture. For example, for centu-
ries artists needed to walk a very fine line in how they
portrayed the human body, specifically to avoid appeal-
ing to prurient interests. Thus, artists often felt
compelled to avoid presenting an unclothed human
1440 body in a ‘‘naked’’ way, which implied some (explicit
or shameful) sexuality, and instead portrayed ‘‘nude’’
bodies, which were construable as a nonshameful
celebration of the human form (e.g., Clark, 1956). Yet
the ubiquity of the unclothed female body—be it in a
1445 ‘‘naked’’ or ‘‘nude’’ form in art, particularly as depicted
by heterosexual male artists—shows that our sensibil-
ities, including our artistic ones, are deeply influenced,
likely in hitherto unrecognized ways, by sexuality. Simi-
larly, in the news and popular media, the interest in sex
1450 scandals, even in an arguably postmodern Western
world presumably jaded by such information, provides
another example of how enduringly and intricately embed-
ded sexuality is within our psyches and culture. Bogaert
(2012b) also examined sexual humor: its ubiquity and
1455
function. Modern psychological models of humor are
often consistent with the notion that it may serve in
part as a (coping) mechanism that helps us negotiate
our way through tensions and complex social rules
(e.g., McGraw & Warren, 2010). Sexuality is an activity
1460
fraught with tensions and complex social-cultural rules
and thus lends itself particularly well to the subject of
humor. If so, one might speculate that asexual people
do not appreciate sexual humor given their lack of need
to negotiate the tensions and complex social-cultural
1465
rules associated with sex, or at least not to the same
degree as average sexual people. However, Bogaert
(2012b) suggested that many asexual people likely
appreciate, or at least understand to a degree, sexual
humor because everyone—sexual or not—is inundated
1470
by sexual references and information in our culture.
Given how embedded and influential sex is in our cul-
ture, along with how sexual humor is likely a coping
mechanism to deal with tensions and socio-cultural rules
surrounding sex, Bogaert (2012b) also suggested it is an
1475
interesting question to ask what our humor would be
like without sex.
Summary and Future Research
Although a wide range of sexual variability has been
recognized throughout human history, and asexual
1480
people were noted by pioneering sexologists such as
Kinsey, asexual people remain an understudied sexual
minority. In the present article, empirical research and
theoretical perspectives on human asexuality were
reviewed. This review concentrated on four main areas:
1485
introductory and contextual issues (i.e., biological and
historical contexts, definitions, and prevalence), psycho-
logical development and variations (i.e., identity and
discrimination, origins, variation based on gender and
masturbation), medical=clinical issues (DSM diagnoses,
1490
whether asexuality is a disorder), and why sexologists
should study asexual people.
Many research questions and scholarly issues remain
(e.g., Bogaert, 2012b; Van Houdenhove et al., 2014b),
and sex researchers as well as colleagues of allied disci-
1495
plines may be able to address a number of gaps in the
literature on asexuality in future work. First, conceptual
and definitional issues still exist, as there is no consensus
on how to best define asexuality. Such definitional issues
present challenges in a number of domains, including in
1500
the meaning and conceptualization of sexual orientation
and how sexual disorders such as HSDD and FSIAD
are construed and diagnosed. Methodological chal-
lenges include a heavy reliance on one Web site=forum
for participants (AVEN; see Brotto & Yule, 2009;
1505
Hinderliter, 2009), and the potential undersampling of
those who would likely never participate in a sex-related
study, including asexuals (Bogaert, 2012b). The study of
asexuality’s origins, identity formation, and variation
BOGAERT
14

17. also remains in its early stages. Using other sexual mino-
1510 rities as models of development (e.g., on origins, identity
formation) may be helpful to a degree, but asexual
people likely have unique aspects to their psychology
toward which researchers need to act sensitively. New
research on gender and masturbation=fantasies, along
1515 with other sources of variability among asexual people,
will also help to understand the range of asexual expres-
sions. Asexuality will also likely continue to challenge
medical scholars and clinicians as to what is or is not
a sexual disorder. In addition, more research is needed
1520 on the mental health of asexual people, along with
whether a potential increased incidence of mental health
issues occurs in asexual people, in part as a result of
a society that often mistrusts and devalues them.
Finally, the degree to which sexuality is embedded in
1525 our society will likely make the study of asexuality an
important counterpointing view for scholars of culture.
These and related future research questions=
endeavors will help to understand this understudied
sexual minority, but studying asexuality may also reveal
1530 a rich cache of untapped knowledge on sexuality,
including psychological and sociocultural aspects—a
main theme of this article. Thus, the asexual world is
worth exploring (or at least considering), even for those
primarily interested in understanding the sexual one.
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