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https://doi.org/10.1177/2372732217720700
Policy Insights from the
Behavioral and Brain Sciences
2017, Vol. 4(2) 194 –201
© The Author(s) 2017
DOI: 10.1177/2372732217720700
journals.sagepub.com/home/bbs
Importance of Biobehavioral Research to Policy
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For gender/sex policy, science shows no one aspect of sex
(hormones, genes, genitals, gonads) trumps others—gender
identity matters most.
Key Points
Sex is a category made up of several variables, none
taking precedence over the others.
Science recognizes that gender matters more for most
policy than sex does.
Biological similarities between mothering and father-
ing support gender-neutral policy, but reproductive
biology (pregnancy, birth, lactation) supports policy
that attends to sex as well.
Attempts to define who can compete as women (or
men) in sports are not based in scientific evidence, but
do lead to stigma and shame, and these include recent
policies about testosterone.
Policies that use birth or current genitals to delimit
who can access single-sex spaces or services are not
based on scientific evidence about the biology of sex
and gender.
Over time, fewer spaces have been reserved for men
or for women, questioning the scientific basis for con-
tinuing sex-segregated spaces.
Introduction
Biological sex is increasingly cited as a basis for making pol-
icy. This policy is used to define sex and gender, differentiate
men and women from each other, and clarify who is allowed
to access single-sex spaces, services, or benefits. As policy
makers define what they mean by sex or gender, and who
counts as a woman or a man (or boy or girl), it is increasingly
clear that these categories are not as obvious as often per-
ceived. But, what is the biological science that these policies
have, or might have, as a basis? This review describes how
science of the biology of sex is relevant to three major policy
areas: parenting (including leaves), sports, and public spaces.
Sex and Gender: What Are They and What Is
the Difference?
Sex and gender can be used in overlapping ways. Because
gender is less likely to evoke sexuality than sex is, gender is
sometimes used in place of sex. Sex and gender are also used
separately. Sex refers to femaleness, maleness, and sex diver-
sity: Evolved bodily features including genitals, secondary sex
characteristics, genes, hormones, gonads (testes, ovaries),
reproductive capacity, and more (Canadian Institutes of Health
Research [CIHR], 2015; Johnson & Repta, 2012; van Anders,
2015). Sometimes nonexperts use biological sex, which has
thus entered some policy language, but scientists generally do
not because it is redundant and carries no scientific meaning
720700BBSXXX10.1177/2372732217720700Policy Insights From the Behavioral and Brain Sciencesvan Anders et al.
research-article2017
1University of Michigan, Ann Arbor, USA
Corresponding Author:
Sari M. van Anders, Department of Psychology, Department of Women’s
Studies, and Program in Neuroscience, University of Michigan,
530 Church Street, Ann Arbor, MI 48109, USA.
Email: smva@umich.edu
Biological Sex, Gender, and Public Policy
Sari M. van Anders1, Zach C. Schudson1, Emma C. Abed1,
William J. Beischel1, Emily R. Dibble1, Olivia D. Gunther1,
Val J. Kutchko1, and Elisabeth R. Silver1
Abstract
Policy debates have focused on who can participate in or access single-sex activities or services. This article describes how
science of the biology of sex is relevant to three major policy areas: parenting (including leaves), sports, and public spaces.
We focus on what scientists know about sex and gender (and gender/sex, where gender and sex are intertwined), and the
role of various biological factors, including hormones such as testosterone and estradiol as well as genetics, gonads, genitals,
and more. The policies under debate often use “biological sex,” but this fails to account for scientific understandings of sex
and gender, misrepresents sex as single-faceted and binary, and overlooks scientific consensus about the importance of
gender and identity.
Keywords
testosterone, genitals, sports, parental leaves, transgender, bathrooms
van Anders et al. 195
beyond just sex. Gender refers to masculinity, femininity, and
gender diversity: sociocultural characteristics including roles,
norms, social structures, laws, and more. Sex and gender are
multifaceted, which means each of them is made up of a set of
variables (Deaux, 1985; Johnson & Repta, 2012; van Anders,
2015).
Overlapping sex and gender can refer to people who are
transgender (whose gender or sex is different from what they
were assigned at birth), cisgender (whose gender or sex is the
same as birth-assignment), gender nonbinary (whose identi-
ties and experiences are not women or men, males or
females), or intersex (whose bodies are perceived, usually at
birth, as not matching expectations for a sex; related phe-
nomena are sometimes called DSDs: divergences/disorders
of sex development).
The scientific consensus is that humans reflect both gen-
der and sex and sociocultural and biological factors (R. J.
Nelson & Kriegsfeld, 2016; van Anders, 2015) and are phys-
ical beings who exist in a complicated social web. This web
reflects that people have gender and many other identities
and experiences. For example, women of different race/eth-
nicities do not necessarily experience being women in the
same way; this is called intersectionality (Crenshaw, 1991).
Accordingly, assumptions that humans come in a gender
binary of two flavors—male and female—ignore the reality
that a multitude of identities influence people’s experiences.
Social identities, experiences, and norms can impact
physical bodies. For example, engaging in masculine-normed
behaviors actually increases testosterone levels in women
and men, and living in low-income, high-pollution areas can
negatively impact sperm development (Najafi et al., 2015;
van Anders, Steiger, & Goldey, 2015; van Anders & Watson,
2006). Sometimes, knowing what is sex (physical) and what
is gender (social) is difficult, because they intertwine and
influence each other. In this case, another term—gender/
sex—can be useful in referring to men, women, boys, girls,
and gender-diverse people, not just males, females, mascu-
linity, or femininity (van Anders, 2015).
How Do Hormones and Other Biological Factors
Relate to Sex and Gender?
When it comes to sex and gender, there are a host of biologi-
cal processes (R. J. Nelson & Kriegsfeld, 2016). Early in ges-
tation, genes code for a gonadal region on the fetal protokidney
to develop into testes or ovaries. All fetuses start with two sets
of reproductive accessories (e.g., uterus, vas deferens) that
are either retained or made to disappear depending on the
presence of testicular hormones. Genitals develop in response
to or absence of exposure to testosterone, into a vulva/vagina
or penis/scrotum, from the same materials. After this, fetuses
develop in the same way regardless of chromosomal, repro-
ductive, or genital sex, and, beyond these differences, babies
and children show no physical differences by sex until
puberty.
At puberty, the gonads, which have been inactive since
early in gestation (except for perhaps two brief periods early
in life, the purpose of which are unknown; Collaer & Hines,
1995) start excreting hormones such as testosterone, estra-
diol, and progesterone. These hormones facilitate developing
and maintaining secondary sex characteristics, some that are
the same by sex (e.g., acne, armpit hair growth, pubic hair)
and some that differ (e.g., patterns of fat distribution, facial
hair growth, menstruation, sperm development). Throughout
adulthood, some continuing sex-related processes are hor-
monally mediated, such as menopause, baldness, sperm-
deterioration, and lactation.
Steroid hormones such as testosterone (an androgen) and
estradiol (an estrogen) are often seen as “opposite” but are
chemically similar. Testosterone is convertible to estradiol,
and can act via estrogen receptors (R. J. Nelson & Kriegsfeld,
2016). Otherwise, each hormone binds to its specific hor-
mone receptor(s). Steroids are released from the gonads
(ovaries; testes), but androgens are also released from the
adrenal glands, which are better known for releasing stress-
related hormones. Steroid hormones can also be converted
from precursor chemicals in fatty (adipose) tissue. These
hormones are not at set, static levels in the body, but reflect a
dynamic interplay between genetic and social factors as well
as environmental and psychological ones (van Anders,
Goldey, & Bell, 2014).
Hormones also affect the brain and influence the likeli-
hood of certain behaviors. In humans, however, the effect of
hormones on behavior is surprisingly weak (Carré & Archer,
2017; van Anders & Watson, 2006). So, while people often
assume that testosterone is what makes men masculine, and
estradiol is what makes women feminine, scientific evidence
about behavior is wanting. This is not for lack of effort; many
studies have attempted to uncover links between testosterone
and aggression, for example, or estradiol and emotionality,
but research demonstrates null associations or only very
weak ones (Hines, 2004; Jordan-Young, 2010). In fact, sci-
entific evidence in humans is much stronger for effects of
behavior on hormones, than for hormones on behavior (van
Anders et al., 2015; van Anders & Watson, 2006). That is not
to say biology does not influence gender/sex behavior, but
instead that influences are difficult to ascertain, and could
not be direct or universal.
Hormones, genitals, gonads, and genes are often used to
define “the gender binary” (usually a sex binary, given the
biological foci). However, a number of factors make up sex,
including genes, reproductive accessories, gonads, hor-
mones, genitals, reproductive potential, secondary sex char-
acteristics, and more, and these do not always co-occur.
Scientists acknowledge no single or objective way to define
sex (Fausto-Sterling, 2000; R. J. Nelson & Kriegsfeld, 2016;
196 Policy Insights from the Behavioral and Brain Sciences 4(2)
Rosario, 2009; van Anders, 2015) and hold that, while sex
can matter, it should not take precedence over gender.
Gender-, Sex-, and Parenting-Related
Policies
Parental leaves, pregnancy leaves, and adoption policies are
often directed toward women or differ by gender/sex. Policy
often builds on women (mothers) as primary caregivers,
which could reflect a host of factors including that preg-
nancy, gestation, and birth are female reproductive events
(excepting transgender men and not universal to all women).
Some policies in the United States recognize this reproduc-
tive sex difference (e.g., most paid parental leaves in the pri-
vate sector, Paid Leave for the United States, 2016) but not
others (e.g., U.S. federal law).
For example, the Family and Medical Leave Act of 1993
(FMLA) offers 12 weeks of unpaid job-protected leave for
reasons including birth/adoption. Any parent—mother or
father—can use the leave to take care of their new child. This
leads to a surprising inequity: Female reproductive biology
(gestation and birth) is not recognized over and above the
need for time to parent. In contrast, policies in some other
countries provide time for parenting as well as pregnancy
(e.g., the Employment Standards Act in Canada [ESA],
2000). Female reproductive biology has been used in other
specific policy areas: excluding women from workplaces or
activities based on pregnancy status or potential (e.g., fetal
protection laws; see Goodwin, 2014). Thus, policies can
apply equally by gender but inequitably by sex.
Policy around parenting often builds on the widespread
perception that women are naturally more caring and loving
than men (Prentice & Carranza, 2002), largely based in ideas
about the biological hardwiring of maternal versus paternal
care (e.g., Taylor, 2003). But, in contrast to the pervasive
idea that women’s bodies are flooded with nurturant hor-
mones like estradiol, which men’s bodies are lacking, we
now know that men and women have indistinguishable lev-
els of estradiol, except during pregnancy or ovulation (R. E.
Nelson, Grebe, O’Kane, & Singh, 2004). And, hormones like
progesterone, which are intimately tied to gestation, are
linked to protective aggression in many species (Mann,
Konen, & Svare, 1984).
A pervasive idea holds that testosterone inhibits parenting
and is higher in all men than in women; in reality, testosterone
levels overlap considerably between women and men
(Sapienza, Zingales, & Maestripieri, 2009). And, what scien-
tists define as parenting has come under scrutiny, since it his-
torically focused only on what mothers did and, even then,
only a selected set of behaviors (van Anders, Goldey, & Kuo,
2011). For example, nurturant parenting behaviors decrease
testosterone levels in men, but hearing baby cries increases
testosterone (van Anders, Tolman, & Volling, 2012). Lower
testosterone correlates with more intimate and caring parent-
ing (Storey, Walsh, Quinton, & Wynne-Edwards, 2000) but
higher testosterone is associated with sensitivity to threat
(Josephs, Newman, Brown, & Beer, 2003). And, greater
involvement in nurturant forms of child care has been linked
to lower testosterone in fathers (Gettler, McDade, Feranil, &
Kuzawa, 2011), while greater involvement in resource-provi-
sioning forms of child care has been linked to higher testos-
terone (Muller, Marlowe, Bugumba, & Ellison, 2009).
Scientific evidence including hormones and brain stud-
ies (e.g., Swain, 2011) challenge policy built on the notion
that men are biologically unprepared to be fathers (unlike
women, who are allegedly natural mothers), or that women
and men are biologically different and complementary par-
ents. This science challenges policy that advocates for chil-
dren to be raised by a mother and father as opposed to
single parents, same-sex parents, or caring others (Patterson,
2006).
Lactation and breastfeeding are elements of parenting that
are sex-specific. Breastfeeding is recommended for babies
until 2 years of age or beyond by the World Health
Organization (WHO, n.d.), and it benefits mothers as well
(Victora et al., 2016). However, health providers and work-
place policies both routinely discourage breastfeeding
directly or indirectly (Marinelli, Moren, Taylor, & The
Academy of Breastfeeding Medicine, 2013; Schmied, Beake,
Sheehan, McCourt, & Dykes, 2011) by not acknowledging
or facilitating a woman’s right to choose to breastfeed/lac-
tate, or the medical recommendations for doing so. An Equal
Employment Opportunity Commission (EEOC) discrimina-
tion complaint against Frontier Airlines by its pilots (Freyer,
2016) charges inadequate lactation-break time (which can
lead to illness or infection in the mother). Not until 2010 did
U.S. federal law require employers to provide lactation
breaks in the Patient Protection and Affordable Care Act
(ACA; Murtagh & Moulton, 2011), and attempts to repeal
the ACA call this into question.
Summary: Implications From Biology for Policy
About Parenting, Gender, and Sex
The science of sex and gender are important for parenting-
related policies, like lactation breaks, access to adoption,
and parental leaves. However, parental leaves are distrib-
uted in a way that fails to take reproductive biology into
account: Although both women and men benefit from
leaves for the time-intensive parenting of babies, sex-spe-
cific events exclusive to women (or transgender men) often
go unrecognized. Science has demonstrated that caregiving
is biologically similar across women and men, challenging
policy that assumes men are biologically unprepared to par-
ent or that women and men are naturally complementary
parents.
van Anders et al. 197
Sport Policy, Gender, and Sex
Sports organizations have long had reason to make gender/
sex-based policy: They excluded women from sport entirely
until relatively recently. Including women in sport has been
accompanied by policy based on concerns described as fair-
ness for or protection of women. These include ensuring that
men do not cheat by competing in women’s sports, because
men generally outperform women. What are these policies
based on?
Policies about who can compete as women are often
called “sex testing” or “gender verification,” though they
apply only to women. They use biology-based criteria
(Westbrook & Schilt, 2014) that have included physical
examination of women athletes’ genitals (often called “geni-
tal parades”) and genetic testing. None of these policies have
caught cheaters; instead, they have identified women who
were intersex or had DSDs. These DSDs, which can include
phenomena such as long clitorises, do not enhance athletic
performance but their often-publicized discovery exposes
identified athletes to shame and stigma (Karkazis, Jordan-
Young, Davis, & Camporesi, 2012).
Other aspects of DSDs, like androgen physiology, concern
policy makers. Although testosterone levels overlap by gen-
der/sex, men show higher average levels than women. In part
for this reason, after other attempts at sex testing failed, con-
temporary policies about who can compete in women’s sports
have been based on maximum acceptable levels of testoster-
one in women. This is based on the assumption that higher
testosterone enhances athletic ability, and accounts for a sex
gap in athletic performance (Allen, 2016; Karkazis & Jordan-
Young, 2015; Wood & Stanton, 2012). What is the science?
The science about testosterone and athletic performance
shows—despite decades of concerted effort—no association
between endogenous (naturally present) testosterone and
athletic success, in either men or in women. No evidence
shows that endogenous testosterone accounts for the differ-
ences in men’s and women’s athletic success (e.g., Court of
Arbitration for Sport [CAS], 2015; Filaire, Bernain, Sagnol,
& Lac, 2001; Frx et al., 2000; Hloogeveen & Zonderland,
1996; Karkazis et al., 2012). Papers that claim otherwise
have used opinion pieces or even Senate hearings rather than
scientific evidence to buttress their claims (e.g., Wood &
Stanton, 2012). One hyperandrogenism policy had argued
that women with “excessive production” of endogenous tes-
tosterone were ineligible to compete as women (International
Association of Athletics Federations [IAAF], 2006). But the
Court of Arbitration in Sport (CAS) recently struck it down,
disagreeing with the IAAF when they could produce no evi-
dence that endogenous testosterone directly contributed to
athletic success, much less that it was the main influence
(CAS, 2015).
How could scientists prove that testosterone has no effect
on athletic success? In actuality, science cannot prove null
effects. Instead, reviews of literature in which articles
repeatedly fail to show an association between testosterone
and athletic success lead objective scientists to conclude that
there is no link; this represents the current science.
Why does belief in testosterone as the determining factor
in (men’s) athletic success persist in the absence of evidence?
One reason is the conflation of endogenous androgens with
doping or exogenously altered androgens, which reflect
pharmacological manipulations that affect testosterone pro-
duction. This matters because exogenously altered andro-
gens affect muscle mass (Bhasin, Woodhouse, & Storer,
2001) and are banned to prevent cheating. But, no evidence
shows that endogenous androgens act on the body in the
same way as exogenous androgens do, and some evidence
shows that they act differently. For example, endogenous and
exogenous testosterone have opposite effects on androgen
receptors (Sader et al., 2005), for reasons that are yet unclear.
Other reasons explain why endogenous testosterone can-
not account for athletic performance. At elite levels of ath-
letic competition, some men and women have low levels of
testosterone, much lower than population averages (CAS,
2015; Karkazis & Jordan-Young, 2015). And, some women
competing in elite athletics have no functioning testosterone.
These are women with androgen insensitivity syndrome
(AIS), who have a Y chromosome that does not code for
functioning androgen receptors. Policy recognizes that they
are women competing with no functional testosterone (e.g.,
IAAF, 2006; International Sports Federation, 2014), yet they
build muscle, compete, and win. Similarly, men with low tes-
tosterone levels compete against other men, and win, and
endogenous testosterone levels do not correlate with ability
to succeed at sports. If testosterone accounted for athletic
performance, none of this could be the case.
The scientific literature opposes common belief. But little
is actually known about endogenous testosterone levels in
women, leaving much room for speculation and ideology to
fill the place of biology (Fausto-Sterling, 2000; van Anders
et al., 2014). Regardless, androgen-based policies have
assigned a maximum testosterone level for women to com-
pete as women in sport, often describing it as the “normal”
lower limit of men’s endogenous testosterone (Allen, 2016).
However, men do not have a normal lower limit of testoster-
one: Levels reach as low as those in women and overlap
between women and men more than presumed (Sánchez,
Martinez-Patiño, & Vilain, 2013). Only more recently have
scientists begun to explore the dynamic variability in testos-
terone (van Anders et al., 2014).
Little scientific basis supports policies about hormone lev-
els and transgender inclusion in sport (Jones, Arcelus, Bouman,
& Haycraft, 2017). For example, exogenous reductions in tes-
tosterone (as with transgender women in sport) are not always
accompanied by reductions in performance; sometimes, there
are actually increases (Harper, 2015), but few studies even
exist. Similarly, no scientific evidence supports assumptions
that estradiol or female reproductive biology account for
198 Policy Insights from the Behavioral and Brain Sciences 4(2)
women’s lower levels of athletic performance, as Serena
Williams’s recent triumph while pregnant exemplifies (Clarey,
2017).
Summary: Implications From Biology for Policy
About Athletics, Sex, and Gender
Policy makers have tried a number of sex-related factors to
determine who can compete as women. Like past attempts,
the most recent attempt—testosterone levels—has failed to
increase fairness or catch cheaters, but has subjected women
to stigma as well as additional layers of policy described as
discriminatory (CAS, 2015; Karkazis et al., 2012; Westbrook
& Schilt, 2014).
Policy for Sex and Gender in Public
Spaces and Documents
Policies regulate who is allowed to enter single-sex spaces in
the United States, highlighting that who counts as a man or a
woman is no longer self-evident. Some policies use gender,
like California’s proposed Gender Recognition Act (GRA;
California State Legislature, 2017). Others use sex, like
Mississippi’s struck-down Protecting Freedom of Conscience
from Government Discrimination Act (Mississippi Legislature,
2016) or North Carolina’s House Bill 2 (HB2; General
Assembly of North Carolina, 2016). But what counts as sex
varies, with genitals often used (e.g., Mississippi Legislature,
2016). However, scientists do not see genitals as defining sex,
nor do they see sex as the definitive aspect of womanhood and
manhood (Fausto-Sterling, 2000; van Anders, 2015).
Some policies (e.g., HB2) use birth certificates to define
whether a person is a man or a woman, as a seeming proxy
for birth sex. However, most U.S. jurisdictions allow indi-
viduals to change their sex on their birth certificates (only
Idaho, Kansas, Ohio, Tennessee, and Puerto Rico do not).
These changes might require genital surgery, a court order, or
a health professional statement (Transgender Law Center,
2017), and differences by location and over time highlight
definitions of sex as dynamic, subjective, and variable (van
Anders, Caverly, & Johns, 2014). Gender-matching birth
certificates facilitate individuals using public spaces that
match their identity, which fits with recommendations by
groups that range from major medical associations to human
rights organizations to the U.S. Federal Government.
Although some policies still focus on genitals, many
transgender people cannot access, cannot afford, or do not
want genital surgery, and many do not see it as important to
their gender. Indeed, a growing cultural and policy consen-
sus understands that genitals are private and do not define
gender (California State Legislature, 2017; Transgender Law
Center, 2017). For example, California’s GRA removes bio-
medical treatment as a requirement for birth certificate
changes.
Some policies seem designed to restrict transgender peo-
ple from using spaces that match their gender/sex (e.g.,
Krieg, 2016), yet increasingly struggle to do so. For exam-
ple, Mississippi proposed legislation (HB1523; Mississippi
Legislature, 2016) that referenced “an individual’s immuta-
ble biological sex as objectively determined by anatomy and
genetics at time of birth.” However, few people know their
genetic sex or have had it identified at birth. And, many peo-
ple have chromosome formations other than “XX” or “XY,”
with estimates such that more than 600,000 Americans would
be unidentifiable according to this policy (Blackless et al.,
2000). An estimated four million more Americans have ana-
tomical sex that does not coincide with their genetic sex
(Blackless et al., 2000). Moreover, anatomy is clearly muta-
ble, changing with age, hormonal state, reproductive status,
and surgical interventions related to gender transition or oth-
erwise (e.g., testicular or penile cancer).
The focus on genitals leads some policy makers to claim
that transgender women are men, and men in women’s bath-
rooms are dangerous to women (e.g., Ura, 2015; see also
Westbrook & Schilt, 2014). Consequently, “trans bathroom
policies” misleadingly enter public debate as issues of men’s
violence against women. For example, student Gavin Grimm
used a boys’ bathroom for weeks with no incident, but his
school banned him from doing so because he is transgender;
parents complained that allowing Grimm to use the boys’
bathroom would allow cisgender boys to dress as girls and
use the girls’ bathroom for sexually predatory behavior
against girls (G.G. v. Gloucester County School Board, 2015).
The focus on men’s violence against women in public bath-
rooms is built on assumptions that men’s biology makes them
naturally dangerous to women. However, men’s violence
toward women is not based in male biology: Testosterone,
which many assume explains men as more aggressive than
women, is only weakly linked to aggression, if at all (Archer,
Graham-Kevan, & Davies, 2005), and scientists have docu-
mented how cultural norms causally link to men’s violence
(Jakupcak, Lisak, & Roemer, 2002). And transgender women
are women; attributing men’s biology or behavior to transgen-
der women is wrong as science and as a basis for policy.
Bathroom policies hurt transgender individuals. It is trans-
gender women who are attacked in women’s bathrooms, by
cisgender women and men (James et al., 2016), and avoiding
gender-policed bathrooms can lead to a host of problems like
urinary tract infections or mental health issues (e.g., G.G. v.
Gloucester County School Board, 2015; James et al., 2016).
Bathroom policies also hurt all women: Because genitals are
rarely seen, any woman or girl who seems insufficiently
womanly, female, feminine, or girlish can have her access to
women-only spaces like bathrooms challenged (Browne,
2004). Because of cultural norms that link whiteness and fem-
ininity (Chin Evans & McConnell, 2003), ethnic minority
women and others seen as not appropriately representative of
women might be deemed especially suspect. These policies
van Anders et al. 199
burden women to publicly present in ways that others decide
reflect their private genital configurations.
Summary: Biological Implications for Policy About
Public Spaces, Gender, and Sex
Efforts to delineate who is allowed in single-sex spaces
reveal definitions of women and men. Much of this policy
seems to be aimed at restricting transgender people, espe-
cially women, from access to public spaces. Doing so has
focused on sex over gender, especially on birth genitals.
Genitals, however, are not the de facto defining feature of
sex; scientists recognize that sex has multiple features and
that sex is not primary over gender, including for defining
who can access public spaces.
Conclusion
Policy uses a variety of definitions of gender and sex, and
there is no one scientific way to define sex, which means that
there is no “getting sex right” for defining women and men
(Cruz, 2010). Indeed, scientists and legal scholars recognize
that gender identity and legal recognition are more relevant
than sex for policy is most cases (Stirnitzke, 2011).
Many arenas once segregated by gender/sex are no longer
so, including schools, workplaces, gyms, clubs, bars, and
(some) religious institutions. One may therefore question the
use of biology to justify ongoing segregation by gender/sex,
because biology does not support a gender binary and, instead,
highlights that sex is multifaceted. Policy based on bioscience
should reflect science that is accurate, up-to-date, and reflec-
tive of biology’s role relative to other social factors.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect
to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, author-
ship, and/or publication of this article.
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