Sex Differences in Math-Intensive Fields

Gender Bias in STEM Fields

The current study focuses on girls’ and women’s reported experiences with gender bias in fields related to science, technology, engineering, and math (STEM). In the first set of analyses, I examined whether the prevalence of self-reported gender bias varied depending on the educational context. I then examined whether experiencing gender bias was associated with lower STEM self-concept and, if so, whether having a supportive network of STEM peers would buffer this effect. Data were collected through a self-report survey that was administered to high school girls who aspired to have STEM careers, women in STEM undergraduate majors, and women in STEM doctoral programs. Overall, 61% of participants reported experiencing gender bias in the past year, but the prevalence rate varied according to their phase of education and field of study. In particular, women in math-intensive undergraduate majors were especially likely to encounter gender bias, which predominately originated from male peers in their major. As expected, participants who encountered gender bias had lower STEM self-concept than participants who did not. However, this effect was attenuated for participants who also had a supportive network of STEM peers. These findings suggest that positive peer connections may be a valuable resource for girls and women in the STEM pipeline.

Breadth-Based Models of Women's Underrepresentation in STEM Fields: An Integrative Commentary on Schmidt (2011) and Nye et al. (2012)

Relative strength of math and verbal abilities and interests drive science, technology, engineering, and math (STEM) career choices more than absolute math ability alone. Having one dominant aptitude (e.g., for mathematics) increases the likelihood of a strong self-concept in that domain and decreases the likelihood of equivocation about career choices in comparison with individuals with equivalent mathematical aptitude who have comparable strength in non-math areas. Males are more likely than females to have an asymmetrical cognitive profile of higher aptitude in math relative to verbal domains. Together, these two points suggest that the academic and career pursuits of high math ability males may be attributable to their narrower options among STEM fields, whereas females' more symmetrical cognitive profile means their math and verbal interests compete in the formation of their ability self-concept and, hence, in their broader career choices. Such equivocation about STEM careers is in fact already evident in girls with high math aptitude as early as junior high school. Thus, we argue that asymmetry in interests and aptitudes is an underappreciated factor in sex differences in career choice. To the extent this is true, focusing on strengthening young women's STEM-related abilities and ability self-concepts to increase female STEM representation may be an unproductive approach; to increase representation, it may be more effective to focus on harvesting the potential of those girls and women whose breadth of interest and high ability spans social/verbal and spatial/numerical domains. The use of interventions that play to this greater breadth by socially contextualizing STEM is one potential solution.

On the gender-science stereotypes held by scientists: explicit accord with gender-ratios, implicit accord with scientific identity

Women's representation in science has changed substantially, but unevenly, over the past 40 years. In health and biological sciences, for example, women's representation among U.S. scientists is now on par with or greater than men's, while in physical sciences and engineering they remain a clear minority. We investigated whether variation in proportions of women in scientific disciplines is related to differing levels of male-favoring explicit or implicit stereotypes held by students and scientists in each discipline. We hypothesized that science-is-male stereotypes would be weaker in disciplines where women are better represented. This prediction was tested with a sample of 176,935 college-educated participants (70% female), including thousands of engineers, physicians, and scientists. The prediction was supported for the explicit stereotype, but not for the implicit stereotype. Implicit stereotype strength did not correspond with disciplines' gender ratios, but, rather, correlated with two indicators of disciplines' scientific intensity, positively for men and negatively for women. From age 18 on, women who majored or worked in disciplines perceived as more scientific had substantially weaker science-is-male stereotypes than did men in the same disciplines, with gender differences larger than 0.8 standard deviations in the most scientifically-perceived disciplines. Further, particularly for women, differences in the strength of implicit stereotypes across scientific disciplines corresponded with the strength of scientific values held by women in the disciplines. These results are discussed in the context of dual process theory of mental operation and balanced identity theory. The findings point to the need for longitudinal study of the factors' affecting development of adults' and, especially, children's implicit gender stereotypes and scientific identity.

Women are underrepresented in fields where success is believed to require brilliance

Women’s underrepresentation in science, technology, engineering, and mathematics (STEM) fields is a prominent concern in our society and many others. Closer inspection of this phenomenon reveals a more nuanced picture, however, with women achieving parity with men at the Ph.D. level in certain STEM fields, while also being underrepresented in some non-STEM fields. It is important to consider and provide an account of this field-by-field variability. The field-specific ability beliefs (FAB) hypothesis aims to provide such an account, proposing that women are likely to be underrepresented in fields thought to require raw intellectual talent—a sort of talent that women are stereotyped to possess less of than men. In two studies, we provide evidence for the FAB hypothesis, demonstrating that the academic fields believed by laypeople to require brilliance are also the fields with lower female representation. We also found that the FABs of participants with college-level exposure to a field were more predictive of its female representation than those of participants without college exposure, presumably because the former beliefs mirror more closely those of the field’s practitioners (the direct “gatekeepers”). Moreover, the FABs of participants with college exposure to a field predicted the magnitude of the field’s gender gap above and beyond their beliefs about the level of mathematical and verbal skills required. Finally, we found that beliefs about the importance of brilliance to success in a field may predict its female representation in part by fostering the impression that the field demands solitary work and competition with others. These results suggest new solutions for enhancing diversity within STEM and across the academic spectrum.

Math achievement is important, but task values are critical, too: examining the intellectual and motivational factors leading to gender disparities in STEM careers

Although young women now obtain higher course grades in math than boys and are just as likely to be enrolled in advanced math courses in high school, females continue to be underrepresented in some Science, Technology, Engineering, and Mathematics (STEM) occupations. This study drew on expectancy-value theory to assess (1) which intellectual and motivational factors in high school predict gender differences in career choices and (2) whether students’ motivational beliefs mediated the pathway of gender on STEM career via math achievement by using a national longitudinal sample in the United States. We found that math achievement in 12th grade mediated the association between gender and attainment of a STEM career by the early to mid-thirties. However, math achievement was not the only factor distinguishing gender differences in STEM occupations. Even though math achievement explained career differences between men and women, math task value partially explained the gender differences in STEM career attainment that were attributed to math achievement. The identification of potential factors of women’s underrepresentation in STEM will enhance our ability to design intervention programs that are optimally tailored to female needs to impact STEM achievement and occupational choices.

Training Spatial Skills in Men and Women

Recent studies suggest that even short-term video game training may transfer to other cognitive tasks. With the popularity of the Nintendo Wii with women, more of them might be exposed to the games that will increase their mental rotation skills. Because performance on mental rotation tests (MRT) has been linked to math performance in women, and thus may ultimately contribute to the under-representation of women in STEM fields, it is important to continue to explore ways to decrease or eliminate the robust sex difference in mental rotation. The present study of 30 men and 30 women provides additional evidence that women may benefit from short-term (1 hour) training on either a Nintendo Wii™ or GameCube console to increase their mental rotation skills. One hour of video game training not only increased women's MRT scores to a level similar to men's scores, but also produced greater average improvement for women, even when controlling for experiential factors such as spatial and masculine childhood activities that could contribute to the sex difference in spatial ability.

Elite male faculty in the life sciences employ fewer women

Women make up over one-half of all doctoral recipients in biology-related fields but are vastly underrepresented at the faculty level in the life sciences. To explore the current causes of women's underrepresentation in biology, we collected publicly accessible data from university directories and faculty websites about the composition of biology laboratories at leading academic institutions in the United States. We found that male faculty members tended to employ fewer female graduate students and postdoctoral researchers (postdocs) than female faculty members did. Furthermore, elite male faculty--those whose research was funded by the Howard Hughes Medical Institute, who had been elected to the National Academy of Sciences, or who had won a major career award--trained significantly fewer women than other male faculty members. In contrast, elite female faculty did not exhibit a gender bias in employment patterns. New assistant professors at the institutions that we surveyed were largely comprised of postdoctoral researchers from these prominent laboratories, and correspondingly, the laboratories that produced assistant professors had an overabundance of male postdocs. Thus, one cause of the leaky pipeline in biomedical research may be the exclusion of women, or their self-selected absence, from certain high-achieving laboratories.

Gender gaps in achievement and participation in multiple introductory biology classrooms

Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel.

Motivational Pathways to STEM Career Choices: Using Expectancy-Value Perspective to Understand Individual and Gender Differences in STEM Fields

The United States has made a significant effort and investment in STEM education, yet the size and the composition of the STEM workforce continues to fail to meet demand. It is thus important to understand the barriers and factors that influence individual educational and career choices. In this article, we conduct a literature review of the current knowledge surrounding individual and gender differences in STEM educational and career choices, using expectancy-value theory as a guiding framework. The overarching goal of this paper is to provide both a well-defined theoretical framework and complementary empirical evidence for linking specific sociocultural, contextual, biological, and psychological factors to individual and gender differences in STEM interests and choices. Knowledge gained through this review will eventually guide future research and interventions designed to enhance individual motivation and capacity to pursue STEM careers, particularly for females who are interested in STEM but may be constrained by misinformation or stereotypes.

Trends in gender segregation in the choice of science and engineering majors

Numerous theories have been put forward for the high and continuing levels of gender segregation in science, technology, engineering, and mathematics (STEM) fields, but research has not systematically examined the extent to which these theories for the gender gap are consistent with actual trends. Using both administrative data and four separate longitudinal studies sponsored by the U.S. Department of Education's National Center for Education Statistics (NCES), we evaluate several prominent explanations for the persisting gender gap in STEM fields related to mathematics performance and background and general life goals, and find that none of them are empirically satisfactory. Instead, we suggest that the structure of majors and their linkages to professional training and careers may combine with gender differences in educational goals to influence the persisting gender gap in STEM fields. An analysis of gendered career aspirations, course-taking patterns, and pathways to medical and law school supports this explanation.

Using a physics experiment in a lecture setting to engage biology students with the concepts of Poiseuille's law

Biology students enrolled in a typical undergraduate physiology course encounter Poiseuille's law, a physics equation that describes the properties governing the flow of blood through the circulation. According to the equation, a small change in vessel radius has an exponential effect on resistance, resulting in a larger than expected change in blood flow. To help engage students in this important concept, we performed a physics experiment as a lecture demonstration to mimic the original research by the 19th-century French scientist. We tested its impact as a research project and found that students who viewed the demonstration reacted very positively and showed an immediate increase in test performance, while the control group was able to independently "catch up" at the fourth week posttest. We further examined whether students' math skills mapped to learning gains. The students with lower math scores who viewed the demonstration had slightly more improvement in test performance than those students who did not view the demonstration. Our data suggest that watching a lecture demonstration may be of even greater benefit to biology students with lower math achievement.

COGNITIVE ABILITIES OF EMIRATI AND GERMAN ENGINEERING UNIVERSITY STUDENTS

According to human capital theory, individual competences and personality attributes are relevant for individual productivity and income. Within human capital, intelligence is crucial. To study engineering and work successfully as an engineer, high cognitive abilities are necessary, especially for work in research and development. In a study of 30 German and 30 Emirati engineering students (mean age: 22 years), both groups were tested with mathematical and figural intelligence scales (CogAT). German engineering students achieved a mean IQ of 116, and Emirati students 104 (in converted UK norms). In both groups male students achieved better results than females (2 to 4 IQ point difference). The results are compared with those from PISA and TIMSS. The possible causes of these results, their consequences and strategies for improvement are discussed.

Gender differences in intellectual performance persist at the limits of individual capabilities

Males predominate at the top in chess, and chess is a useful domain to investigate possible causes of gender differences in high achievement. Opportunity, interest and extent of practice can be controlled for. Organized chess has objective performance measures, extensive longitudinal population-level data and little gatekeeper influence. Previous studies of gender differences in chess performance have not controlled adequately for females on average playing fewer rated games and dropping out at higher rates. The present study did so by examining performance of international chess players at asymptote and over equal numbers of rated games. Males still were very disproportionately represented at the top. Top female players showed signs of having less natural talent for chess than top males, such as taking more rated games to gain the grandmaster title. The hypothesis that males predominate because many more males play chess was tested by comparing gender performance differences in nations with varying percentages of female players. In well-practised participants, gender performance differences stayed constant even when the average national percentage of female international players increased from 4.2% to 32.3%. In Georgia, where women are encouraged strongly to play chess and females constitute nearly 32% of international players, gender performance differences are still sizeable. Males on average may have some innate advantages in developing and exercising chess skill.

Not lack of ability but more choice: individual and gender differences in choice of careers in science, technology, engineering, and mathematics

The pattern of gender differences in math and verbal ability may result in females having a wider choice of careers, in both science, technology, engineering, and mathematics (STEM) and non-STEM fields, compared with males. The current study tested whether individuals with high math and high verbal ability in 12th grade were more or less likely to choose STEM occupations than those with high math and moderate verbal ability. The 1,490 subjects participated in two waves of a national longitudinal study; one wave was when the subjects were in 12th grade, and the other was when they were 33 years old. Results revealed that mathematically capable individuals who also had high verbal skills were less likely to pursue STEM careers than were individuals who had high math skills but moderate verbal skills. One notable finding was that the group with high math and high verbal ability included more females than males.

Science faculty's subtle gender biases favor male students

Despite efforts to recruit and retain more women, a stark gender disparity persists within academic science. Abundant research has demonstrated gender bias in many demographic groups, but has yet to experimentally investigate whether science faculty exhibit a bias against female students that could contribute to the gender disparity in academic science. In a randomized double-blind study (n = 127), science faculty from research-intensive universities rated the application materials of a student-who was randomly assigned either a male or female name-for a laboratory manager position. Faculty participants rated the male applicant as significantly more competent and hireable than the (identical) female applicant. These participants also selected a higher starting salary and offered more career mentoring to the male applicant. The gender of the faculty participants did not affect responses, such that female and male faculty were equally likely to exhibit bias against the female student. Mediation analyses indicated that the female student was less likely to be hired because she was viewed as less competent. We also assessed faculty participants' preexisting subtle bias against women using a standard instrument and found that preexisting subtle bias against women played a moderating role, such that subtle bias against women was associated with less support for the female student, but was unrelated to reactions to the male student. These results suggest that interventions addressing faculty gender bias might advance the goal of increasing the participation of women in science.

Leaks in the pipeline: separating demographic inertia from ongoing gender differences in academia

Identification of the causes underlying the under-representation of women and minorities in academia is a source of ongoing concern and controversy. This is a critical issue in ensuring the openness and diversity of academia; yet differences in personal experiences and interpretations have mired it in controversy. We construct a simple model of the academic career that can be used to identify general trends, and separate the demographic effects of historical differences from ongoing biological or cultural gender differences. We apply the model to data on academics collected by the National Science Foundation (USA) over the past three decades, across all of science and engineering, and within six disciplines (agricultural and biological sciences, engineering, mathematics and computer sciences, physical sciences, psychology, and social sciences). We show that the hiring and retention of women in academia have been affected by both demographic inertia and gender differences, but that the relative influence of gender differences appears to be dwindling for most disciplines and career transitions. Our model enables us to identify the two key non-structural bottlenecks restricting female participation in academia: choice of undergraduate major and application to faculty positions. These transitions are those in greatest need of detailed study and policy development.

Early androgen effects on spatial and mechanical abilities: evidence from congenital adrenal hyperplasia

There is considerable controversy about the origins of sex differences in cognitive abilities, particularly the male superiority in spatial abilities. We studied effects of early androgens on spatial and mechanical abilities in adolescents and young adults with congenital adrenal hyperplasia (CAH). On tests of three-dimensional mental rotations, geography, and mechanical knowledge, females with CAH scored higher than their unaffected sisters, and males with CAH scored lower than their unaffected brothers. Exploratory regression analyses suggest that androgens affect spatial ability in females directly and through male-typed activity interests. Findings indicate that early androgens influence spatial and mechanical abilities, and that androgen effects on abilities may occur in part through effects on sex-typed activity interests.

Do Subtle Cues About Belongingness Constrain Women's Career Choices?

Nilanjana Dasgupta's (this issue) stereotype inoculation model (SIM) helps explain why what feels like a free choice to pursue one life path over another "is often constrained by subtle cues in achievement environments that signal who naturally belongs there and is most likely to succeed and who else is a dubious fit" (p. 231). She posits that seeing others like themselves in successful roles inoculates women against negative stereotypes that impede their success and persistence in specific achievement contexts.As is true of classic theoretical positions (see Nagel, 1961), Dasgupta presents postulates from which she deduces a specific set of hypotheses, and she reviews the relevant empirical/observational data in support of them. It is precisely what this area of research has long needed-moving beyond demonstrations of identity threats to a theory about their underlying causes, conditions, and interventions. This proposal leads her to four broad predictions, the first of which is the primary focus of our comment.

A Theory of Sex Differences in Technical Aptitude and Some Supporting Evidence

In this article, I present a theory that explains the origin of sex differences in technical aptitudes. The theory takes as proven that there are no sex differences in general mental ability (GMA), and it postulates that sex differences in technical aptitude (TA) stem from differences in experience in technical areas, which is in turn based on sex differences in technical interests. Using a large data set, I tested and found support for four predictions made by this theory: (a) the construct level correlation between technical aptitude and GMA is larger for females than males, (b) the observed and true score variability of technical aptitude is greater among males than females, (c) at every level of GMA females have lower levels of technical aptitude, and (d) technical aptitude measures used as estimates of GMA for decision purposes would result in underestimation of GMA levels for girls and women. Given that GMA carries the weight of prediction of job performance, the support found for this last prediction suggests that, for many jobs, technical aptitude tests may underpredict the job performance of female applicants and employees. Future research should examine this question.

Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition

Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right.

Can Sex Differences in Science Be Tied to the Long Reach of Prenatal Hormones? Brain Organization Theory, Digit Ratio (2D/4D), and Sex Differences in Preferences and Cognition

Brain organization theory posits a cascade of physiological and behavioral changes initiated and shaped by prenatal hormones. Recently, this theory has been associated with outcomes including gendered toy preference, 2D/4D digit ratio, personality characteristics, sexual orientation, and cognitive profile (spatial, verbal, and mathematical abilities). We examine the evidence for this claim, focusing on 2D/4D and its putative role as a biomarker for organizational features that influence cognitive abilities/interests predisposing males toward mathematically and spatially intensive careers. Although massive support exists for early brain organization theory overall, there are myriad inconsistencies, alternative explanations, and outright contradictions that must be addressed while still taking the entire theory into account. Like a fractal within the larger theory, the 2D/4D hypothesis mirrors this overall support on a smaller scale while likewise suffering from inconsistencies (positive, negative, and sex-dependent correlations), alternative explanations (2D/4D related to spatial preferences rather than abilities per se), and contradictions (feminine 2D/4D in men associated with higher spatial ability). Using the debate over brain organization theory as the theoretical stage, we focus on 2D/4D evidence as an increasingly important player on this stage, a demonstrative case in point of the evidential complexities of the broader debate, and an increasingly important topic in its own right.

Understanding current causes of women's underrepresentation in science

Explanations for women's underrepresentation in math-intensive fields of science often focus on sex discrimination in grant and manuscript reviewing, interviewing, and hiring. Claims that women scientists suffer discrimination in these arenas rest on a set of studies undergirding policies and programs aimed at remediation. More recent and robust empiricism, however, fails to support assertions of discrimination in these domains. To better understand women's underrepresentation in math-intensive fields and its causes, we reprise claims of discrimination and their evidentiary bases. Based on a review of the past 20 y of data, we suggest that some of these claims are no longer valid and, if uncritically accepted as current causes of women's lack of progress, can delay or prevent understanding of contemporary determinants of women's underrepresentation. We conclude that differential gendered outcomes in the real world result from differences in resources attributable to choices, whether free or constrained, and that such choices could be influenced and better informed through education if resources were so directed. Thus, the ongoing focus on sex discrimination in reviewing, interviewing, and hiring represents costly, misplaced effort: Society is engaged in the present in solving problems of the past, rather than in addressing meaningful limitations deterring women's participation in science, technology, engineering, and mathematics careers today. Addressing today's causes of underrepresentation requires focusing on education and policy changes that will make institutions responsive to differing biological realities of the sexes. Finally, we suggest potential avenues of intervention to increase gender fairness that accord with current, as opposed to historical, findings.