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Feminist Critiques of Neuroimaging Sex/Gender Difference Research
Rebecca Fritz
Program of Gender Studies
University of Notre Dame
May 3, 2018
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Abstract
Many neuroscientists have used the neuroimaging technology of today in an attempt to
discern the neurological differences between men and women. However, neuroimaging
sex/gender difference research often ignores the input of scholars in the humanities, social
sciences, psychology, etc. This review brings together the fields of feminist scholarship and
neuroscience by reviewing feminist critiques of this research. Ambiguous definitions of sex and
gender as well as the entrenchment of stereotypes and preconceptions skews neuroscience
towards a limited understanding of sex/gender categories. Further, low sample size, prevalence
of false positives, within-group analysis, and publication/citation bias decrease the reliability,
validity, and statistical power of these studies. Finally, results are interpreted in such a way that
the influence of neuroplasticity goes largely unaccounted for, and structure and function are
assumed to be directly related, causing a restricted and essentialist view of sex/gender. Further
integration of gender knowledge into neuroscience may ameliorate these weaknesses.
Keywords: sex/gender, neuroimaging, publication bias, neuroplasticity
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Introduction
The rapidly flourishing field of neuroscience has seen immense growth in recent decades.
With the development of functional magnetic resonance imaging machines, scientists’
knowledge about the brain is more expansive than ever before, and continues to grow. Recently,
this field of scientific inquiry has set its sights on a common debate: differences between men
and women. Many neuroscientists have used modern technology to try to discern the
neurological differences between men and women. Typically, these studies require men and
women to be exposed to the same stimuli, while neuroimaging (NI) technology gathers data on
their brain activity during exposure. For clarity, this specific field of neuroscientific inquiry will
be referred to as “NI sex/gender difference research” throughout this review. A discussion of the
use of “sex/gender” is provided as one of the first topics in the body of this review.
Neuroscience (broadly) and NI sex/gender difference research (specifically) largely
ignore the input of scholars from the humanities, social sciences, psychology, etc. In particular,
gender studies and feminist scholars have developed a large body of work on gender, sex, other
intersecting identities, and their differences that reflect the power structures of our society. While
the broader movement of feminism contains countless definitions of this term within it, a
generally feminist approach to science is one that carefully considers the constructed nature of
gender categories and uses knowledge of these categories to evaluate both the ideas that society
and culture glean from them, and their intersection with the human element of scientific inquiry
(Valentine, 2008).
Given that neuroscience is enamored with determining neurological sex/gender
differences, it seems logical that such inquiry should include input from the fields of academia
that focus specifically on understanding sex and gender. Thus, the paper will review critiques
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grounded in feminist theory and gender studies of neuroscience research practices within the
field of NI sex/gender difference research. The critique will be broken up into two sections:
definitions and preconceptions, and interpretations of results. In first section, the review will
cover definitions of sex and gender, biases that affect the research questions that get asked, the
prevalence of false positives, the danger of small sample sizes, the use of within-group analyses
to make conclusions between groups, and publication/citation bias. The second section will
discuss why NI sex/gender difference research must carefully consider the principle of
neuroplasticity and work to challenge the assumption of a causal relationship between neural
structure and function/behavior.
Feminist Critiques
Definitions and Preconceptions
Definitions of sex and gender. Feminist scholars highlight one main critique of
neuroscientific research on sex/gender differences that is rooted in an analysis of the
methodology employed in neuroscience studies. A thorough review of the critiques of
neuroscientific methodology in these studies must begin with questioning terms used by
neuroscientists. Nikoleyczik (2012) rightfully points out a major flaw in a number of cognitive
science and neuroscience studies regarding sex and gender: The studies themselves frequently do
not define the terms sex and gender. This may be because “gender” and “sex” are commonly
understood to be self-explanatory, though feminist scholars and scholars of sex and gender
would strongly disagree (Nikoleyczik, 2012). According to Nikoleyczik (2012), most papers that
study sex/gender-based neurological differences not only fail to define the terms “sex” and
“gender,” but also use these terms interchangeably and often prioritize an explanation related to
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hormones or evolutionary theory over an understanding of gender as a powerful and influential
socio-cultural concept.
Feminist scholars and social scientists alike often take a social constructivist approach to
understanding sex and gender. Nikoleyczik (2012) provides a feminist, social constructivist view
of gender as “a cultural inscription on the naturally sexed body” (p. 234). That is to say, gender
is not a naturally occurring phenomenon, but is created by culture and imposed on individuals by
culture (Nikoleyczik, 2012). Sex, too, can be considered to be socially constructed; feminist
scholars argue that sex is neither a determinant of gender nor completely separate from
conceptions of gender (Nikoleyczik, 2012). While some feminist scholars disagree on the exact
definition of sex (Jordan-Young & Rumiati, 2012; Nikoleyczik, 2012), the general consensus is
that sex is irrevocably influenced by cultural definitions of gender (Jordan-Young & Rumiati,
2012); the medical categorization of physical anatomy is rendered meaningless without careful
consideration of how gender may impact these definitions and categories (Nikoleyczik, 2012).
To be sure, the terms “gender” and “sex” are difficult (perhaps impossible) to fully separate, and
similarly difficult to define in such a way that all parties fully agree (Nikoleyczik, 2012).
However, within feminist academic circles, scholars agree that these terms have distinct
meanings and must be treated as distinct concepts (Jordan-Young & Rumiati, 2012).
According to gender and feminist scholars, sex is considered to be a constructed category
based on anatomical features, such as the presence of a penis, while gender refers to “culture-
bound conventions, roles, and behaviors” (Nikoleyczik, 2012, p. 234). Furthermore, gender is
multi-dimensional and performative; gender identity, how one perceives oneself within the
gender binary, and gender expression, how one presents oneself according to preset cultural
expectations of specific genders, are two ways in which gender may be manifested. In the field
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of NI sex/gender difference research, it is not clear which dimension of gender is meant when the
term “gender” is used (Nikoleyczik, 2012). Gender and feminist scholars argue that both
categories are informed by social and cultural values and a heavy reliance on a binary system.
However, without an understanding of the distinction between gender and sex, the research
questions posed by sex/gender-difference neuroscience lack a comprehensive and culturally
conscious perspective, allowing for vague and sometimes misleading results. Within the
biological and medical scientific community, one’s gender is often assumed to follow from one’s
sex category, which is not always an accurate assumption.
This assumption is also known as essentialism, or the claim that “there are natural kinds
whose members share a common essence” (Haslam & Whelan, 2008, p. 1297). In the case of
gender, an essentialist perspective is one that treats sexual anatomy as a signifier for a certain
category – gender – and the members of that category share deep-seated similarities because of
this observable external similarity (Haslam & Whelan, 2008). Neuroscientists in NI sex/gender
difference research often employ an essentialist perspective in their work, which is demonstrated
by the collapse of the distinction between sex and gender. By failing to provide adequate
definitions of the terms, neuroscientists suggest that sex and gender are interchangeable and thus
indistinguishable from one another. This reduces gender to mere anatomy and limits possible
knowledge about the nuances of gender and sex as complex sociocultural constructs.
While I understand and advocate for a separation of the definitions of sex and gender, the
treatment of these concepts by neuroscience makes it incredibly difficult to utilize appropriately
nuanced and accurate definitions of these terms while reviewing the current literature. To avoid
further confusion on this matter, the term “sex/gender” will be used throughout this review when
referring to studies that are focused on discerning the differences in brain activity and patterns
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between men and women, because the research that will be critiqued fails to provide operational
definitions for these crucial terms.
Biases influencing empirical inquiry. Included in this broad topic of methodological
critique is an analysis of the specific research questions that are developed, and for what purpose.
In the neurological research of sex/gender differences, researchers have a tendency to prioritize
questions that emphasize possible disparity of responses between men and women (Roy, 2012).
While this may indeed be a critique applicable to science on the whole, it is especially important
to acknowledge the the implications of this tendency when the brain is the focus, considering the
sensitivity of discussions of sex/gender and gender. In her recent article, “Neuroethics, Gender
and the Response to Difference,” Roy (2012) argues that scientists interested in doing this work
must identify what their true goal is in pursuing this knowledge. Roy (2012) makes an important
distinction between conducting research to explore sex/gender-based neurological difference for
the sake of attaining a greater understanding of individual difference, or for the sake of creating a
divide between men and women. To drive her point home, Roy (2012) considers the historical
19th-century practice of phrenology, which was a specific study of the brain that relied on skull
size to determine one’s intelligence, character, and mental capacity. This pseudoscience allowed
for racist and sexist beliefs to be supported by medical research, thereby legitimizing the practice
of discrimination against certain races (Roy, 2012). White Europeans, who were responsible for
the introduction of phrenology, based their inquiries on a preconception that non-white and non-
male individuals were less capable and less intelligent than their white male counterparts. Thus,
the claims borne of this discipline focused on skull size were used to denigrate other races.
The characteristics of the producers of scientific and empirical knowledge have remained
largely unchanged; the field of neuroscientific research is still composed primarily of white men,
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as are a number of other fields of scientific inquiry. Thus, Roy (2012) has reason to be concerned
that new technologies for studying the brain could be used as tools of oppression for already
marginalized groups, such as women. Evidence proclaiming significant differences between
female and male brains has the potential to crystallize notions of female inferiority (Bluhm,
2013; Roy, 2012). The example of phrenology illustrates how scientific research (whether or not
it is truly scientific, so long as it is held up as scientific fact) can and will be used in service of
the machinery of white heteropatriarchy, particularly if said scientific research is created by the
society’s privileged groups, which it often is.
In this way, neuroscience cannot be considered to be untouched by social and cultural
factors. Despite the tendency to hold up the natural sciences as a paragon of objectivity, “the
facts, theories and practices that emerge from brain research are always cultural and historical
products, with particular political and economic trajectories” (Vrecko, 2012). That is to say,
neuroscience is and always will be colored by sociocultural, human factors (Vrecko, 2012). For
example, the pervasive nature of gender scripts, or how we expect individuals to act based on
their gender presentation, affects neuroscientific research as much as it affects interpersonal
interactions. In this review, NI sex/gender difference research is recognized as a product of
cultural and historical understandings of what certain anatomical features mean for an
individual’s gender identity, and by extension, their specific strengths, weaknesses, personality
traits and so on.
For example, in a number of studies examined by Roy (2012), researchers explored the
neural-based responses to visual sexual stimuli in men and women (Gizewski et al., 2006;
Hamann, Herman, Nolan, & Wallen, 2004; Takahashi et al., 2006). In these studies, participants
were separated into male and female groups, which clearly demonstrates that the studies
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themselves relied on the prevailing assumption that men and women respond differently to visual
sexual stimuli (Roy, 2012). The studies did not question the previously constructed groups or the
preconceptions of the researchers (Roy, 2012). For example, Gizewski et al. (2006) claim in their
introduction that men respond more strongly to visual erotic experience “according to common
experience” (p. 102). To be fair, Gizewski et al. (2006) also cite a number of scientific articles to
support their assumption. However, the inclusion without questioning of a source that - as it is
presented - seems to rely solely on anecdotal evidence indicates that Gizewski et al. (2006) are
not interested in questioning the stereotypes and assumptions that the previous literature has
passed down.
Another study described by Roy (2012) serves as an example of how preconceptions can
cause researchers to interpret results in a way that is more favorable to normative cultural
understandings of sex/gender. Takahashi et al. (2006) posited their study as a way to understand
domestic violence, which is undoubtedly an important global issue that should be addressed
(Roy, 2012). Results indicated that men show more activation in the hypothalamus and
amygdala, which the authors claimed to be centers of production of sexual and aggressive
behaviors (Roy, 2012). The brain areas referenced as the cause of male aggression – the
hypothalamus and the amygdala – serve a number of purposes in the brain. For example,
scientists widely recognize the amygdala as also responsible for the fear response; however, this
interpretation was left out of the analysis of the the study’s results. Roy (2012) criticized the
study, arguing that they failed to contribute any new meaningful information to the discourse
surrounding domestic violence. Instead, the study in question served to uphold the problematic
and dangerous stereotype that men have an innate tendency toward violence (Roy, 2012). Studies
such as the ones that Roy (2012) examined suggest that male aggression/violence is biological, a
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claim allegedly supported by the activation of the amygdala and the hypothalamus when jealousy
is experienced. When men are seen as “biologically” aggressive and violent, that behavior is
often excused, which puts women and gender/sexual minorities at risk. Thus, the researchers’
division of participants into sex/gender categories with differences justifies the dominance of a
specific sex/gender in cultural and social settings.
According to the critique presented by Roy (2012), neuroscientists’ obsession with
discovering neurological sex/gender-based differences does not bode well for women or
gender/sexual minorities, groups that are often marginalized to begin with under the regime of
white patriarchy. A number of consequences can be imagined here; neuroscientific research has
the capacity to influence legislation, reify cultural norms, and even shape personal
understandings of selfhood (Vrecko, 2010). In the previously given example of domestic
violence, results indicating “natural” male aggression may afford perpetrators of abuse the
benefit of the doubt, or legal advantages that may not be deserved. Since the research questions
themselves guide the course of scientific discovery, feminists have critiqued the frequent use of
division of the sex/genders in the development of neuroscientific inquiry. In the specific field of
NI sex/gender difference research, division by sex/gender category lends itself well to a cultural,
political, legal, and social reinforcement of preexisting stereotypes and roles.
False positives. Questions about the use of divisive language in research aside, feminist
scientists and scholars have also offered a number of other critiques of this field’s
methodological approach. Like any field of empirical research, neuroscience is capable of
producing errors. One such error is the Type I error, or a false positive. A false positive occurs
when researchers incorrectly reject a null hypothesis: in other words, when statistical
significance is found for a result when there is no true difference, or the result is due to chance
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(Simmons, Nelson, & Simonsohn, 2011). False positives are, according to Simmons et al.
(2011), quite costly mistakes. Once false positives are found, they persist throughout the
literature, often causing further research into a fruitless inquiry and wasting time and resources
(Simmons et al., 2011).
A psychologist known for writing on the intersections of gender and neuroscience,
Cordelia Fine, regularly provides critique of NI sex/gender differences research. Her work
integrates gender knowledge with a comprehensive understanding of statistics and data analysis,
making her critiques less philosophical than those posed by critics discussed thus far. Fine’s
perspective focuses on the specific methodologies used in the design of studies and the analysis
of results, as well as the factors that influence publication. Fine (2013) suggests that false
positives may be a large issue in sex/gender-difference neuroscientific research. NI sex/gender
difference research often seeks to discover one specific difference between men and women, and
its inquiries are fairly easily imagined and tested (Fine, 2013). Fine (2013) reminds consumers of
neuroscientific NI sex/gender difference research that the conventional measure for statistical
significance indicates that five out of one hundred significant results occur due to chance. As
Fine (2013) puts it, “if twenty researchers routinely test for sex differences then, even if there is
no real difference between the populations, one researcher will find a statistically significant
difference” (p. 371). That is to say, in the field of NI sex/gender difference research, where
evidence based on small sample sizes is used to claim a significant difference between the
sex/genderes, the result of a single study is not necessarily reliable (Fine, 2013). Fine (2013)
argues that the prevalence of false positives is not as widely recognized and attended to within
the field of NI sex/gender difference research as it perhaps should be, in the interest of upholding
the integrity of the research.
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One explanation for the occurrence of false positives in NI sex/gender difference research
is presented by Hyde (2014), who discusses at length the statistical analyses often utilized in NI
sex/gender difference research. For context, Hyde (2014) favors the idea of identifying gender
similarities: the hypothesis that the genders are more alike than they are different deserves to be
tested, and researchers should focus on discovering similarities instead of difference. A number
of theories support this idea. For one, while some evolutionary scientists may argue that the
process of sexual selection naturally creates gender differences, the strength of natural selection,
a genderless process, outweighs that of sexual selection (Hyde, 2014). Sociocultural and
cognitive social learning theories suggest that as social and cultural conditions improve for
marginalized genders, all genders will feel more comfortable pursuing gender-unconventional
pathways and skills (Hyde, 2014). Thus, it will be important in the future to test extensively for
gender similarities, as these theories expect to see the similarities grow (Hyde, 2014).
Unfortunately, the statistical methods used in NI sex/gender difference research rely on the
scientific convention of searching for difference, producing evidence that the genders are more
different than they are alike – the opposite of the gender similarities theories (Hyde, 2014). The
predominant method takes a linear combination of a number of variables, which, according to
Hyde (2014), yields results that are difficult to interpret and whose difference is maximized. This
maximization of difference in a specific statistical method is one example of how false positives
may occur within NI sex/gender difference research.
Sample size. Sample size is another factor that makes studies particularly vulnerable to
false positives (Rippon, Jordan-Young, Kaiser, & Fine, 2014; Simmons et al., 2011). Small
sample sizes make results difficult to generalize to the larger population and renders the
statistical power of the study in question much lower than if the sample size were larger (Rippon
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et al., 2014). In the context of NI sex/gender difference research, the gender similarities theories
as well as measured empirical data suggest greater similarity between the genders than difference
(Hyde, 2014; Rippon et al., 2014). Given this well-supported conclusion, researchers must
consider the amount of overlap between the genders (Rippon et al., 2014). Considering the
amount of overlap between the genders, the effect measured in most cases will likely be marginal
(Rippon et al., 2014). Thus, a large sample size is necessary to adequately measure reliable
differences (Rippon et al., 2014).
In order to illustrate the prevalence of small sample sizes in the field of NI sex/gender
difference research, Fine (2013) conducted a meta-analysis of sorts. The study involved
searching several databases for articles whose titles included the phrase “sex difference” in order
to investigate the typical sample sizes for different studies in NI sex/gender difference research.
Fine (2013) collected thirty-nine articles that fulfilled her criteria. After careful analysis of the
studies’ sample sizes, she found that the average number of males included in the studies was
19.0 and that the average number of females included in the studies was 18.5 (Fine, 2013). In
studies that made sex-by-age comparisons, greater sample sizes were required for statistical
analysis, so the average number of male and female participants increased to 32.7 and 26.3,
respectively, among these studies (Fine, 2013). In studies that examined sex-by-group effects,
the mean sample sizes were 11.9 males and 11.4 females per subgroup (Fine, 2013). When Fine
(2013) eliminated the sex-by-group and sex-by-age comparative studies, the mean sample sizes
for studies that looked solely at sex/gender comparisons were 13.5 and 13.8 for male and female
participants, respectively.
Fine (2013) argues that the sample sizes used in this research endeavor are insufficient to
generalize to the larger population. According to her analysis, “the majority of studies had (a
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mean of) fifteen or fewer participants of each sex in each of their groups of interest” (Fine, 2013,
p. 374). Fine (2013) also found that it was equally as likely for a study to have fewer than ten
participants as it was for a study to have greater than twenty participants, regardless of the nature
of the comparison. Given that these studies are representative of the field of NI sex/gender
difference research, as they all referred to sex/gender differences as their primary topic in the
title of the article, it may be concluded from Fine’s (2013) analysis that the sample sizes used to
assess sex/gender differences neurologically may not be sufficient to draw significant
conclusions that apply to the general public.
Within-group analyses. Another statistical failing of the field of sex/gender differences
research is its reliance on within-group analyses (Bluhm, 2013; Rippon et al., 2014). Within-
group analyses determine average measures of a variable in the groups that are tested and
compare the average measures, instead of comparing between groups directly (Bluhm, 2013).
Researchers in the field of sex/gender difference neuroscience often conduct within-group
analysis and report differences between sex/genders based on this analysis, when no direct
comparison has actually been made between the groups (Bluhm, 2013; Rippon et al., 2014). For
example, a NI sex/gender difference study claiming a significant difference may show that in the
male group tested, there was a level of activity in a certain brain area that reached significance,
while in the women no significant activity was found (Bluhm, 2013). In this case, the
neuroscientists have assumed that, because that brain area was significantly active in men and
not in women, that brain area is more active in men than in women in a certain situation (Bluhm,
2013). This may or may not be true, depending on the degree of significance in both groups;
their activity levels may actually be quite similar (Bluhm, 2013). This kind of analysis disguises
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differences within groups and produces statistical significance when it may not be accurate to
claim (Bluhm, 2013).
When variability within groups is minimized or masked altogether, understandings of the
groups are limited. It is a restrictive approach not only to sex/gender, but science as well. The
findings of such studies are destined to generalize, producing limited knowledge about the
research question. Furthermore, the failure to base claims of group differences on a comparison
between groups is irresponsible and misleading. Within-group analysis may also be a
contributing factor to the prevalence of false positives within the field of NI sex/gender
difference research.
Publication and citation bias. Even after studies have been conducted and reported on,
the method by which this information is published and circulated is biased towards a certain kind
of result. Fine (2013) notes the problem of publication bias in the field of NI sex/gender
difference research; very few studies reporting no difference between groups – including the
sex/genders – are published in academic journals or held up as important discoveries. Instead, an
analysis of the literature suggests that the field is significantly more interested in reporting on
difference between the sex/genderes (Fine, 2013). It is, after all, the field of NI sex/gender
difference research, not sex/gender similarity research. At any rate, this publication bias only
serves to reinforce the preexisting hypothesis that there are significant neurological differences
between men and women, instead of approaching the inquiry of sex/gender difference
holistically and also allowing for the dissemination of studies that discover no significant
difference, but instead significant similarity, especially when differences are expected (Fine,
2013).
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It has recently been shown that none of the differences found in the field of NI sex/gender
difference research have been consistently repeated (Wallentin, 2009, cited in Dussauge, 2012).
Clearly, the field has trouble demonstrating reliability – likely for all of the reasons discussed
thus far. This fact also suggests that the evidence of the field of NI sex/gender difference
research could simply reflect a haphazard assortment of differences found, as a result of the
publication bias in favor of studies that claim statistically significant differences between the
sex/genders.
A deeper dive into this phenomenon reveals that publication bias is, in a way, cyclical in
nature. Fine (2013) claims that once a certain study is published and becomes part of the
accepted literature on the topic, other researchers may cite it in ways exaggerate the magnitude
of the major finding of the study. In the specific example of NI sex/gender difference research
and publication bias, researchers looking to use previously published studies as citations may
focus on evidence within a study that supports the idea of neurological sex/gender differences,
instead of acknowledging other findings that illustrate or support neurological similarities
between men and women (Fine, 2013).
Independent of her sample-size meta-analysis, Fine (2013) investigates one such study by
Shaywitz et al. (1995) by considering closely how the study has been cited by other researchers.
To be clear, the study by Shaywitz et al. (1995) found statistical evidence of sex/gender
differences in the functional organization of the brain with regards to phonological processing –
that is, the comprehension of spoken and written language. However, the study also revealed no
difference between men and women with regards to brain activity for orthographic and semantic
processing (Shaywitz et al., 1995). Orthographic processing refers to the use of the visual system
to form, store, and recall words, and semantic processing refers to the mental relationships
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formed between words based on their definitions. Furthermore, several meta-analyses were
conducted that presented compelling evidence regarding gender differences in phonological
processing contradictory to the Shaywitz et al. (1995) study. In her investigation into publication
and citation bias, Fine (2013) determined that the Shaywitz et al. (1995) study had been cited
ninety-two times in a two year period, and that seventy-five of those citations could be included
in Fine’s analysis. Studies were excluded if they were not written in English, if they
misrepresented the premise or inquiry of the study, or if they did not use the results of the
Shaywitz et al. (1995) study to speak about gender/sex/gender specifically (Fine, 2013).
The investigation revealed that only three of the seventy-five citations referred to the
failure to find sex/gender differences in orthographic and semantic processing in the Shaywitz et
al. (1995) study (Fine, 2013). To the authors’ credit, several studies did clarify that the
sex/gender difference applied specifically to phonological processing (Fine, 2013). However, the
remaining citations neglected to report the overwhelming absence of significant differences in
the study, and instead focused on the small section of the study that did, in fact, report difference
(Fine, 2013). The exposure of these practices suggests that even after the influence of publication
bias, there is a kind of citation bias, which is enacted when other scientists and researchers
choose specific results to highlight in their own studies (Fine, 2013). At times, this may result in
a misrepresentation of the evidence gathered in the original study. In the case of sex/gender
differences, this citation bias creates a cycle where researchers depend upon previous findings of
difference, however weak they may be, to fuel their own inquiries and conclusions about
neurological sex/gender differences. This cycle upholds traditional understandings of gender and
forces neurological research to remain constricted by the gender and sex binary, which, in
essence, is to remain constricted in a system of patriarchal power.
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A system that depends on a binary of both sex and gender necessarily upholds the
dominance of one group over another, while erasing any variability of the categories it has
created. Patriarchy is fueled by the subjugation of other sex/gender categories, just as white
supremacy relies on the disenfranchisement of people of color (and in fact, these two systems are
intimately linked). That is to say, dominant groups under white patriarchy hold a vested interest
in creating clear and distinct gender boundaries, because it simplifies the process of maintaining
power. When groups are clearly divided, they are easier to control.
Interpretation of Results
The feminist and methodological critiques of neuroscientific research with specific
regards to sex/gender differences have been presented and explained above, but this is not the
extent of scholarly critique. Although feminist scholars are by no means the only academics in
the business of critiquing neuroscience, a significant portion of feminist critique centers on the
interpretation of the research in question: specifically, NI sex/gender difference research.
Interpretations of scientific results are often informed by a pre-existing theory, that
carries with it certain assumptions. The following section will discuss which theories are
employed in interpretations of NI sex/gender difference research, which are not, and what
assumptions these theories rely upon. The theories discussed are that of neuroplasticity and the
relationship between structure and function.
Neuroplasticity. The first of the critiques of interpretation relates to a failure to take
neuroplasticity into account when researching neurological sex/gender differences. The concept
of neuroplasticity – a widely accepted phenomenon amongst neuroscientists – indicates the brain
will be responsive to the influences of the environment (Fine, Jordan-Young, Kaiser, & Rippon,
2013; Kraus, 2012). Neuroplasticity is the notion that the brain has the capacity to change over
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the course of one’s lifespan (Kraus, 2012). The brain responds to environmental factors and life
experiences, and adjusts accordingly. Feminists hold up this principle of neuroscience as an
opening for critique of NI sex/gender difference research. In terms of gender and sex,
neuroplasticity suggests that the gendered and sexed components of one’s environment shapes
one’s brain; thus, neuroscientists should be critical of results that indicate neurological
differences based on biological sex, since those differences could be created by the individual’s
experience living in a gendered and sexed body (Fine, Jordan-Young, Kaiser, & Rippon, 2013;
Kraus, 2012). Again, this point does not belong solely to gender and feminist scholars, but it is a
consistent with feminist critique.
If the brain has the capacity to change over the course of one’s life in response to specific
experiences and exposure to any given stimuli, then it becomes incredibly difficult to determine
whether any neurological activity can be determined solely by biological factors associated with
sex/gender. In this way, the principle of plasticity challenges deterministic brain studies, or those
that link brain structure or function in a specific scenario to a constructed identity such as gender,
sex/gender, race, etc (Kraus, 2012). Kraus (2012) emphasizes that the concept of plasticity
suggests the importance of the influence of social structures on the brain; human growth and
development should not be seen as completely determined by neurological and biological agents
and processes but also influenced by the social and environmental factors at play. Focusing too
much on the importance of biology in understanding gender bolsters the essentialist perspective
that neuroscience currently holds regarding gender.
In another critique centering on plasticity, Fine (2013) compares the reliance on fMRI
studies to produce reliable knowledge about neurological sex/gender differences to taking a
picture with a camera. Just as no information can be gleaned from a “snapshot” of the past, no
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information can be gleaned from fMR images about what factors occurred in the past to shape
the brain in this specific way (Fine, 2013). Thus, the use of imaging studies to conduct NI
sex/gender difference research necessarily ignores the principle of neural plasticity. At present,
neurological studies of sex/gender differences based on imaging have no way of accounting for
the effects of past experience on brain development and function.
In fact, many feminist scholars argue that the significant results that may be produced in
NI sex/gender difference research are a result of an individual living in a gendered and
sex/gendered environment (Fine, 2013; Fine et al., 2013; Kraus, 2012). Per the definition of
gender from Nikoleyczik (2012), which argues that gender is inscribed on the body, feminist
scholars argue that gender may also be inscribed on the brain through gender-related
experiences. To support this idea, Fine (2013) draws on the example of stereotype threat.
Stereotype threat can be defined as a phenomenon that indicates individual performance on
certain tasks is influenced by the prevalent stereotypes about that individual’s identity (Fine,
2013). For example, young girls perform better on mathematical tasks when the task de-
emphasizes the stereotype that girls are bad at mathematics (Fine, 2013). Were there to be
neurological imaging NI sex/gender difference research done on these young women, it is quite
possible that there would be a significant difference in the brain activity of those girls who were
exposed to the stereotype and those who were not. Given an all-female sample, if differences in
mathematical ability were found, it would be clear that these differences were not due to
sex/gender. However, NI sex/gender difference research often excludes the possibility that
individuals’ brains may be affected and shaped by factors other than biological sex by not
designing research that explores the effect of plasticity.
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To further illustrate this point, scholar Ginger Hoffman describes brain activity as ever-
changing and impermanent (Hoffman, 2012). She writes that when a person shifts their gaze
from one object to another (for example, when shifting one’s gaze from one’s computer to one’s
desk drawer to look for a pencil), that person’s brain activity looks different (Hoffman, 2012).
Based on this example, Hoffman argues that “assessing brain activity at any given point in time
in no way implies that that activity will be there forever, or even a long time” (Hoffman, 2012, p.
34). This echoes previous discussions of plasticity; it is clear that many feminists and
neuroscience researchers do not find the current model of measuring brief neural patterns in
response to specific stimuli to be an accurate or reliable method for researching neurological
sex/gender differences. According to Hoffman (2012), a wealth of research indicates that
environmental differences in childhood and early development have the ability to promote as
well as inhibit brain development. Hoffman (2012) concedes that the brain may not be infinitely
malleable, and that this question is one to be explored further by neuroscientific research.
However, a difference shown in an fMRI study does not imply any sort of fixedness (Hoffman,
2012).
Assumed relationships between structure and function. Similar to the reductive nature
of ignoring properties of neuroplasticity, the field of NI sex/gender difference research also
assumes a linear connection between brain structure and human behavior or function (Jordan-
Young & Rumiati, 2012; Roy, 2012). In her article, “Neuroethics, Gender and the Response to
Difference,” Roy (2012) advocates for a more complicated understanding of the human brain.
Roy’s (2012) critique rests on the idea that neuroscientists in this field ignore the principle of
neuroplasticity; she warns against assuming that differences in anatomy suggest differences in
behavior. In other words, when neuroscientists ignore the importance of neuroplasticity in
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understanding gender, they encourage an understanding that brain function is determined by
brain structure. Roy (2012) argues that instead, neuroscientists should entertain – and even
explore – the notion of a more complex relationship between structure and function, suggesting
NI sex/gender difference research studies that explore how multiple structures may be linked to a
specific function, or how multiple functions may be linked to a specific structure.
Similarly, Jordan-Young & Rumiati (2012) work to dismantle the “hard-wired” paradigm
that permeates popular understandings of NI sex/gender difference research. The authors argue
that the paradigm is unethical and misleading for a number of reasons, including the argument of
neuroplasticity discussed above. The “hard-wired” paradigm presents human behavior as a direct
output of neural activity in specific brain structures heavily – and perhaps solely – shaped by
biological sex (Jordan-Young & Rumiati, 2012). In this way, the paradigm reduces possible
relationships between sex/gender and behavior to an overly-simplistic, linear, and essentialist
connection. By considering the brain to be “hard-wired,” neuroscientists also assume gender to
be “hard-wired” in a way that drastically limits the range of human expression and experience.
Furthermore, when brain structure and function are assumed to be directly related,
reverse inferences are often made. According to Rippon et al. (2014), reverse inferences occur
when “activation in particular brain regions is taken to equate to a specific mental process and,
by extension, differences in activation can be taken to indicated differences in ability or
efficiency” (p. 8). In other words, reverse inference allows one to map stereotypes onto measured
effects (Rippon et al., 2014). Thus, the assumption of a direct relationship between structure and
function increases the likelihood of the field of NI sex/gender difference research to be used to
reinforce stereotypes and disenfranchise certain groups.
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Conclusions
The field of NI sex/gender difference research, a growing area of neuroscience, aims to
explore possible neurobiological bases of sex/gender in humans. For a topic that deals with
complex, sensitive topics such as sex and gender, it is shocking how little knowledge from
gender and feminist scholars – the academics who spend their time, energy, and resources
conceptualizing sex and gender in responsible and comprehensive ways – is incorporated into the
field. Integration of these fields, or at least dialogue between them, would allow for more
responsible science in the area of NI sex/gender difference research.
Feminist scientists and scholars critique NI sex/gender difference research on the basis of
definitions, preconceptions, and interpretations. First, neuroscientists typically fail to
differentiate between sex and gender (Nikoleyczik, 2012), two terms that have quite different
meanings within the field of gender studies (Jordan-Young & Rumiati, 2012). Neuroscientists
also use surprisingly small sample sizes in these studies, which leaves the research more
vulnerable to false positives, or Type 1 errors (Fine, 2013; Rippon et al., 2014). Within-group
statistical analyses presented as comparisons between groups misrepresent measured differences
as more meaningful than they may actually be (Bluhm, 2013). Finally, even after the studies are
developed, conducted, and written up, publication is more likely to be afforded to studies that
present difference instead of similarity (Fine, 2013; Hyde, 2014). The same pattern of focusing
on differences holds true for citations as well (Fine, 2013).
Feminist scientists and scholars also point out that NI sex/gender difference research
ignores neuroplasticity as a possible explanation for differences between the sex/genders (Kraus,
2012). An understanding of neuroplasticity suggests that behavior and function cannot be
essentialized to one’s assigned sex at birth, since the brain constantly changes and grows in
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response to life experience (Kraus, 2012). Furthermore, the same idea – that biological and
anatomical qualities serve as the reasons for certain behaviors or brain function – upholds the
neuroscientific assumption that brain structure is directly related to function. A more complex
understanding of the relationship between structure and function would be a more responsible
and comprehensive approach to grasping concepts of neurological function (Roy, 2012).
Given the historical and continuing obsession with determining differences between the
sexes, it is understandable that neuroscience as a field of inquiry is interested in addressing these
differences. However, neuroscientists have a responsibility to treat this problem with care, and
could learn a great deal about the relationship between the brain and sex and gender if they
consider the perspectives of the scholars that devote their career to studies these categories.
Inclusion of gender knowledge in sex difference research has the capacity to inform the field in a
constructive and positive way that allows for responsible science to be produced within the
setting of a white, capitalist patriarchy.
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