The assumption that boys are naturally drawn to – and inherently skilled at – math and science while girls are predisposed to the more liberal arts is deeply embedded in our culture. And it is continually reinforced and perpetuated by observations that boys do in fact do better in these areas. There is evidence, however, that this so-called “sex gap” is shaped by sociocultural factors. A recent report found, for example, that differences in math performance have been declining over time. Another revealed correlations between the size of the gap and national indicators of gender egalitarianism. If aptitude for math and science were somehow intrinsic to boys and not to girls, we probably would not see such variability across time and place.Brian A. Nosek, an associate professor of psychology at the University of Virginia in Charlottesville, and colleagues decided to explore the influence of sociocultural factors, looking specifically at the role of implicit, or unconscious, stereotypes about gender and science. “Stereotypes have often been implicated in contributing to the sex gap, but the evidence for self-reported stereotypes predicting such outcomes is mixed. We thought that implicit stereotype measures might be more effective predictors because they do not require self-awareness of possessing them, and they can exist in people’s minds even if they are consciously rejected,” he explained.Nosek serves as director of Project Implicit, which seeks to uncover the differences between conscious and unconscious attitudes through administration of Implicit Association Tests (IATs). Visitors to the Project Implicit Web site (http://implicit.harvard.edu/) can complete tests covering a range of topics: measuring association strengths, for example, between gender (male, female) and academics (science, liberal arts). Those who participated in the gender-science component completed the test, a short questionnaire that measured beliefs and attitudes, and math and science and demographics questionnaires.For a study published in the June 30 issue of PNAS, Nosek and a number of colleagues from across the globe looked at IAT data collected between May 2000 and July 2008. More than half a million IATs were completed during this time. The researchers focused specifically on the nearly 300,000 tests completed by citizens of the 34 countries covered by the 2003 Trends in International Mathematics and Science Study (TIMSS). This facilitated comparison with the results of that study, in which standardized exams of math and science achievement were administered to samples of eighth-graders.They reported three main findings: (1) The implicit association tests confirmed the existence of implicit stereotypes associating males with science much more so than females. (2) The investigators found that nation-level implicit stereotypes predict nation-level sex differences in achievement in eighth-grade science and math. And finally, (3) they noted that self-reported (that is, conscious) stereotypes do not predict differences in achievement.So what does this tell us? First, on some unconscious level, many people still assume that males have greater aptitude for math and science than females – even if they have convinced themselves that they believe otherwise. The PNAS study shows that more than 70 percent of the 500,000+ IAT respondents were more apt to associate males with science and females with liberal arts than the reverse. That said, the extent to which people make such assumptions varies considerably, both across individuals and across cultures.Which brings us to the second take-home lesson: There is a strong correlation between how well people think males and females will do in math and science and how well they actually do, as recorded by the TIMSS. Nosek and colleagues avoid the obvious and unanswerable chicken-and-egg question here, but they note that implicit gender stereotypes and sex gaps are mutually reinforcing. Because they are exposed to the stereotypes pretty much from birth, girls often show less interest than boys in science and math, and as a result they may not perform as well in these areas. This serves to reinforce the belief that boys are more inherently skilled in math and science. And so on.While governments around the world are working to close the sex gap in science and math, it is not yet clear which interventions have been the most or the least effective. Researchers and policy makers will want to know, however. “Those questions are highly important and surely among the next issues to investigate in this research,” Nosek said.