Sources of the Gender Gap

Rebecca Y Hu

Sources of the Gender Gap: An analysis of the disparities in mathematical and spatial abilities between sexes

Rebecca Y Hu

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Rebecca Y Hu

Abstract The cause of discrepancy in mathematical and spatial reasoning abilities between males and females is currently a central area of contention in fields ranging from psychology to sociology.

This disparity is clearly manifested through male dominance in math- and science-related occupations and superior male performance in mathematical and spatial reasoning tests. This paper explores the two main sources of this widely acknowledged discrepancy—one that addresses the inherent neurological differences between sexes and the other that emphasizes the impact of social and cultural expectations in forming and maintaining gender roles and stereotypes. Both confer considerable influence on the observed gender gap, which can lead to adverse effects—such as stereotype threat and gender discrimination—as well as positive outcomes—such as the balance of duties and responsibilities within families. Although society as a whole should strive to standardize equal gender access to education and resources, we should also acknowledge the inherent emotional and behavioral differences that exist between men and women.

I. Introduction One of the most prominent debates in psychology and social studies today is the source of distinction between sexes in abilities that involve mathematical, spatial, or logical reasoning. Larry Summers, former president of Harvard University, aptly summarized the ‘nature’ side of the argument in 2005 when he proclaimed that women are innately less able to succeed in math and science careers (Dillon 2005). His claim stems from a broader assertion that the presence of innate biological differences between sexes is the main cause of this distinction. These differences range from disparities in the volumetric measurements of brain parts to varied patterns of neural activation (Ngun et al. 2011). Opponents of this theory, on the other hand, ascribe the gender gap mainly to the presence of discrimination and other societal pressures. According to this point of view, the gender roles and stereotypes imposed on women by their society, especially in regards to their role in STEM (science, technology, engineering, mathematics) fields, directly impact their abilities to practice and present their mathematical and spatial abilities (Kiefer and Sekaquaptewa 2007).

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II. Presence of Gender Disparities in Everyday Life Early sex differences. Even among young children relatively untainted by the pressures of gender role conformity, the presence of increased mathematical and spatial ability among males is pronounced. Young boys, starting at just four years of age, become especially well equipped with the innate mental machinery to perform tasks involving mental rotation (Levine et al. 1999). This phenomenon clearly demonstrates the gender difference in both skill of and preference towards mathematics-centered activities. Additionally, in a study testing the different approaches to problem solving in 18- to 24-month-old toddlers, boys are proven to rely much more heavily on geometry and spatial recognition than girls (Lourenco et al. 2011). These data provide substantial support for the argument attributing sex differences to innate biological structures. Since these children are young and are relatively free of the burden of conforming to gender stereotypes, any differences present between the sexes would most likely be derived from structural disparities in the brain. However, because natural skill might lead to increased exposure and rehearsal, the data might also lend credence to the claim that this subtle gender difference early on in life pushes males to exercise these activities more often, creating a positive feedback loop between innate and nurtured abilities.

Occupational gap. The gender gap in mathematical ability is most clearly manifested by comparing the proportion of men and women in STEM field occupations. Even today, there is a distinct underrepresentation of women in the highest levels of scientific and mathematical fields (Ceci et al. 2009). This may be due to either the presence of less interest among women in STEMrelated activities or a dearth of resources for women interested in such fields. Additionally, a statistical analysis of the wages earned by men and women reveal that salary disparities continue to exist between the sexes (Gibelman 2003). Gibelman (2003) posits that much of this disparity is due to the continued presence of gender discrimination in the workplace despite the implementation of decade-old policy aimed at reducing gender bias in the office environment.

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Standardized testing scores. A comparison of standardized tests scores indicates that males consistently perform better in math subjects, which points to their superior mathematical ability. Unsurprisingly, this disparity widens even further in higher levels of schooling—i.e. high school and beyond (Hyde et al. 1990). This implies that gender stereotypes may play a role in creating a negative image of women in STEM fields, thus triggering a negative feedback loop that hinders women from pursuing their mathematical or scientific interests. Literature also suggests that the results of these tests remain relatively consistent over time for individuals. In fact, a study done by Lachance and his colleagues (2006) demonstrates that achievement levels in kindergarten are usually accurate predictors of the achievement levels attained in third grade and beyond. These findings indicate that there is an unmistakable gender gap in STEM achievement that may be initially due to biological differences but that are solidified through social pressuring and reinforcement.

Implications. The gender gap is a phenomenon that makes a constant presence throughout life. It first appears among young children, in the form of increased spatial and mathematical abilities among boys, and extends to educational settings and eventually the workplace. This consistency suggests that there may be multiple factors at play. Initially triggered by subtle differences in brain structure, this discrepancy may foster a preference and talent in males toward STEM-related activities. In this way, a positive feedback loop is created, in which biological factors affect social and intellectual functions and preferences, which eventually strengthen neural networks and connectivity. Thus, not only are neurological differences and social norms themselves factors that lead to this apparent gender gap, but the interaction between the two factors can reinforce this disparity between sexes.

III. Biological Differences Between Men and Women

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Differences in brain size. Male brains are, in general, approximately 10% larger than female brains (Zaidi 2010). Contrary to popular belief, this phenomenon does not account for an increased level of intelligence in males but rather develops as a result of the larger neural network designed to control the larger body size of males (Zaidi 2010). There also exist differences in the proportion of white matter and gray matter between men and women—female brains generally have a higher percentage of gray matter whereas male brains show a higher percentage of white matter (Gur et al. 1999). However, the total volume of gray matter remains higher in men. Because sheer tissue volume, rather than the proportion of tissue in relation to brain volume, is associated with higher mental performance, men are able to perform difficult mathematical and spatial tasks with relative ease compared to women (Gur et al. 1999).

Differences in particular regions of the brain. Aside from the difference in the overall volume of the brain, men and women also share differences in the size of particular regions of the brain, especially those involved in mathematical and spatial calculations. For example, the interiorparietal lobe (IPL), a region highly associated with mathematical ability, is significantly larger in males. More specifically, males possess a much larger IPL in their left hemisphere than in their right hemisphere—the left IPL is shown to be involved intricately in spatial visualization and mental rotation of objects whereas the right IPL is involved mainly in spatial relationships (Zaidi 2010). A study that localized brain activity through fMRI signaling shows that the amount of brain activation per degree of mental object rotation is more than 200% higher in males than in females (Keller and Menon 2009). These statistics point to a clear biological superiority in males to execute STEM-related activities. Additionally, male and female brains differ in the pattern of cortical lobe division—women have a much larger frontal lobe, which correlates with a heightened level of emotional sympathy and decision-making, whereas men have a larger parietal cortex, which translates into an increased sense of space perception (Zaidi 2010). Thus, in comparable situations, women are more tuned in to their emotional inclinations whereas men are more likely to exercise their computational and logical functions.

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Right brain dominance in males. In general, women experience a higher level of cortical connectivity and cognitive efficiency in their neural networks (Gong et al. 2009). However, even the distribution of neural network efficiency is different between sexes: women have a higher efficiency in the left hemisphere of the brain whereas men experience higher right brain efficiency (Gong et al. 2009). Furthermore, males experience a greater lateralization of function in their right hemisphere, specifically in regions including the superior temporal, inferior frontal, and inferior occipital cortices (Tomasi and Volkow 2012). Because the right hemisphere expresses dominant control over spatial perception and function, the structural pattern of neural connections in the male brain induces more efficient spatial processing.

Differences in learning approaches. Aside from the structural differences in the brain, studies have shown that men and women use different parts of their brain in response to the same task or activity. For example, women prefer to use regions of their brain that specialize in emotional and verbal processing whereas men prefer regions that correspond to spatial and mechanical function (Zaidi 2010). This explains why males show more interest in tasks that involve hands-on modeling or spatial diagrams of problems—their brains are wired to receive and interpret information in ways that involve systems building. On the other hand, females approach problems through analysis of emotional and verbal cues—thus, they are hardwired to offer emotional support and sympathy in these situations (Zaidi 2010).

Implication of results. These findings generally lend credence to the claim that men possess certain neurological characteristics that allow them to more efficiently process mathematical and spatial calculations. However, these data do not and should not lead to the generalization that all men possess a heightened sense of mathematical and spatial reasoning compared to all women—indeed, these results are meant to present an average of the differences between sexes. Moreover, a number of studies that show differences in neural response activity between sexes actually demonstrate no clear difference in behavioral response; thus, the disparities between the physical components of the brain doesn’t necessarily lead to a consistent difference in the level of neuronal function (Zaidi 2010). Nevertheless, speaking on a general level, there is

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much scientific evidence that bolsters the claim that men are biologically more wired to engage in STEM activities and occupations than women. These innate differences may consequently lead to societal pressures that dictate differing gender roles and stereotypes, thus expanding the biological gender disparity.

IV. Social Pressures and Stereotypes Leading to These Differences Gender inequality. Cross-cultural studies demonstrate a negative correlation between the size of the gender gap and the percentage of women in the workface (Hyde and Mertz 2009). These data reflect the impact of overall gender inequality on the barriers to math and science. The US, as one of the more gender equal nations of modern society, boasts a dramatic improvement in recent years of mathematical performance among females (Hyde and Mertz 2009). This improvement is largely due to the standardization of resources—such as STEM-focused specialties and majors— between genders and the emphasis on math and science curriculum for females in high school and higher-level education. These findings indicate that much of the gender gap in STEM-related occupations is due to an inequality in the distribution of resources between genders, which is a direct consequence of society’s differing perceptions of the intellectual capacity and social standing of males and females.

Cultural expectations and pressures. Due to their heightened level of emotional sensitivity, females are more susceptible to the pressures of societal conformity. In particular, their academic interests and learning approaches are highly influenced by their educational and familial environments. For example, in countries where the education system is standardized across genders, the gender gap is highly diminished because women face less anxiety towards their gender identity (Ayalon and Livneh 2013). This demonstrates the impact of the educational setting on shaping women’s perception of their own academic capabilities. Additionally, because girls don’t engage in as much hands-on and system-building activities in their daily schedule as boys, increased exposure in hands-on lab experience greatly boosts the level of academic achievement

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among females (Hyde 2006). Family settings, particularly the maternal perspective on gender roles, can also greatly influence girls’ perceptions of their mathematical and reasoning abilities. A strong positive correlation exists between parents’ estimates of their children’s academic ability and their children’s actual abilities—as measured through standardized tests (Hyde 2006). Additionally, because females usually look to their mothers as role models, evidence suggests that mothers who perpetuate gender stereotypes increase the level of vulnerability in their daughters to stereotype threat (Tomasetto et al. 2011). Thus, because women and girls are more emotionally sensitive and experience a more significant psychological impact by societal norms, they are easily affected in settings that discourage or even decline to promote female involvement in mathematical and scientific activities.

Social influences on neural circuitry. Aside from impacting women’s psychological states, social influences and expectations can actually lead to fundamental changes in the wiring and patterning of neuronal circuitry. Studies of brain plasticity demonstrate the ability of the anatomy and neural networks of brains to change over time (Zaidi 2010). As certain neural pathways and certain regions of the brain are activated more often, plasticity of the brain leads to both the strengthening of these pathways and the enlargement of these brain areas. Specifically, according to the Hebbian theory, “neurons that fire together wire together,” affecting the overall structure and function of the neural circuitry (Brunel 1996). In contrast, synapses that are not frequently used eventually become eliminated from the neural pathway. Thus, environmental variables can actually influence and change the biological wiring of the brain, demonstrating the effect that social pressures have on both psychological and biological bases. Because males are more inclined to utilize and execute the parts of their brains relating to mathematical and spatial reasoning, these parts of their brains become enlarged and strengthened over time. The variable cortical thickness across sexes during adolescent development also demonstrates the effect of social pressures on brain anatomy (Giedd et al. 2012). In males, cortical thickness increases during

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adolescence in parietal regions as a result of increased neural activation, again reflecting the impact of exposure to STEM-related tasks on the biological restructuring of the brain.

Stereotype threat. Stereotype threat refers to the anxiety—in this case, by women—that is brought about through fear of fulfilling or perpetuating some negative stereotype. As the source of the self-fulfilling prophecy, stereotype threat visibly confers adverse effects on women (O’Brien and Crandall 2003). In a study conducted by O’Brien and Crandall (2003), female subjects reminded of gender stereotypes before a math test perform significantly poorer on difficult problems than those not exposed to such a psychological trigger. However, the same results are not present in men, as men do not experience the same stereotypes regarding their academic ability.

These results suggest the possibility of a negative feedback loop—stereotype threat leads to poor testing performance, which leads to low self-confidence, which leads to even poorer testing performance. In another study, women are arranged into two groups to watch clips of scientific conferences—in one group, the clip shows an extremely low ratio of women, while in the other, the clip shows a relatively balanced ratio of women to men. Unsurprisingly, those exposed to the unbalanced ratio feel the realistic effects of the gender barrier and are in turn more hostile and vigilant (Murphy et al. 2007). The results of these studies demonstrate the immediate—if not fully conscious—impacts brought about by stereotype threat and reflect the deep root that these gender stereotypes have in modern culture.

Gender roles. From a young age, boys engage in activities that involve more physical and spatial reasoning, foreshadowing the “masculine” role that they will eventually take on as the main provider of the family. For example, even during infancy, boys prefer games that involve physical activity and spatial perception, whereas girls prefer games that involve verbal participation and emotional reasoning (Nazareth et al. 2013). This early transition into gender roles eventually leads to the characterization of women as the caretaker of the family. Thus, in order to juggle

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responsibilities between work and family, women often prefer to work fewer hours and take on part-time jobs in order to achieve that balance (Ceci and Williams 2011). Moreover, due to the demanding and time-intensive nature of many STEM disciplines, women generally prefer careers in non-math-intensive fields (Ceci et al. 2009). For example, many STEM-related fields penalize women with children by offering lower and fewer promotion rates and frown upon family obligations such as maternity leave (Ceci et al. 2009; Williams 2006). Nonetheless, in many of these situations, women usually make the conscious decision to drop priorities in work and focus on family. In fact, many current beliefs about gender discrimination in grant funding, hiring, and journal review are largely proven false (Ceci et al. 2009). Although women can often be susceptible to the negative effects of gender stereotype, many consciously embrace certain aspects of these gender roles in order to create the balance between family life, work life, and social life. Thus, the existing gender roles can simply be a reflection of the difference between genders in their values and life goals that lends itself to a positive balance in familial and societal function.

Other contributing factors. There are many other third-level confounding factors that may lead to the gender gap. First of all, men are universally agreed to be much more aggressive than women (Zaidi 2010). Aggressive attitudes usually lead to higher societal and occupational status, which can explain the overwhelming majority of men in top positions in math- and science-related fields. A second factor relates to women’s susceptibility to emotional turmoil—because women are more emotional and undergo a more rapid regulation of serotonin and dopaminergic pathways, they are more likely to become depressed than men (Zaidi 2010). Most occupations in the STEM field are often quick-paced and do not allow for emotional dips; thus, most women are unable to handle the rigor of such work (Cosgrove et al. 2007). Finally, women generally have much lower selfesteem than men and are often reluctant to accept positions of authority (Chusmir and Koberg

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1991). Again, this difference in personality indirectly explains the high proportion of males in top STEM positions.

V. Conclusion Discussion. Both biological and social factors contribute to the widespread discrepancy between sexes in mathematical and spatial ability and to the occupational gender gap. Much of the gender disparity is in fact due to an interaction between these two factors—the combination of which presents itself in the form of a current lack of female representation in STEM-related fields.

However, to say that all men are better than all women at math and science is a drastic oversimplification. Just as people of different racial and ethnic backgrounds cannot be generalized into one characterization, we should be mindful of the spectrum of individual differences when referencing the general disparities between men and women. In fact, despite all their differences, male and female brains are overwhelmingly more alike than different (Giedd et al. 2012).

Future goals. Future policies aimed at reducing this gender gap should focus on standardizing math and science curriculum across genders and offering women a support system for gender identity discussion (Hyde 2006). These policies include creating a curriculum for spatial learning, implementing a math and science requirement for girls in high school, placing emphasis on problem solving strategies in math classes, and educating girls about the dangers of stereotype threat (Johns et al. 2005). In general, we should aim at creating an equal playing field for men and women in terms of opportunities and resources for STEM. We should also keep in mind that, as evinced by the neurological differences between sexes, men are inherently much more inclined to mathematical and spatial activities than women. Additionally, not all effects of the gender gap are negative—in fact, many women by nature prefer to work in non-math-intensive occupations and create a more balanced lifestyle for themselves. Thus, the push for equality shouldn’t force a 50-50

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distribution of men and women across the STEM fields but rather create a standardized system of support for individuals across all social, cultural, and economic sectors.

The creation of such a system involves gradual changes in infrastructure and social support and cannot be achieved in a quick fashion. However, one simple step that can confer immediate change involves diffusing the emphasis on negative stereotypes. Akira Miyake, a physics professor from the University of Colorado, demonstrates the power of stereotypes in his experiment adapted from Geoffrey Cohen’s famous “15-minute writing exercise” experiment. In his simple study, he directed his students to perform a 15-minute exercise that focused on their interpretation of important morals and values. The result was astounding: “With nothing but his fifteen-minute exercise, performed twice at the beginning of the year, he virtually abolished the gender divide and allowed the female physicists to challenge their male peers” (Yong). Thus, Miyake clearly demonstrates that gender roles that work to restrain a certain gender’s creativity or aspirations can negatively affect future occupational work. Although the gender gap cannot be so easily defeated, it’s in society’s best interest to unearth those inaccurate gender ‘myths’ in order to free its people from the restricting reigns of bigotry that still stain the professional workplace.

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