The enormous gender gap in science, technology, engineering, and math (STEM) participation has surfaced as a global issue in recent decades. According to the latest report by the National Science Foundation (2019), male scientists and engineers take more positions (62.2% vs. 37.8%) and receive higher salaries ($90,000 vs. $66,000) than do their female peers in the United States. The gender–science stereotype describes an automatic and habitual belief that men are more talented and interested in STEM than women. The gender–science stereotype is prevalent among both men and women, from young children to seniors, across a broad range of scientific disciplines, and in most ethnicities and nations around the world. (Are you interested in taking the Implicit Association Test? (Here you can access the test https://implicit.harvard.edu/implicit/takeatest.html at Project Implicit®)
Recent molecular genetic studies of implicit social cognition have involved implicit attitudes (implicit racial attitude), implicit personalities (implicit extraversion), implicit stereotypes (implicit gender-strength stereotype), and implicit motives (implicit drinking motive). Several genetic polymorphisms previously considered included the polymorphisms in the serotonin-transporter (5-HTTLPR) gene, oxytocin receptor (OXTR) gene, brain-derived neurotrophic factor (BDNF) gene, and catechol-O-methyltransferase (COMT) gene.
To examine genetic sources of the gender–science stereotypes, scientists studied adolescents from the Beijing Twin Study (BeTwiSt) and repeated the subsample 2 years later. For this analysis, two genetic polymorphisms, rs4680 in COMT gene and rs6265 in the BDNF gene were selected because a previous study has shown that rs6265 moderates gender-strength stereotype among patients with prefrontal lesions. The regular Implicit Association Test (IAT) and brief IAT were administered to measure how one agreed with gender–science stereotypes. The IAT measures associations between concepts (e.g., Liberal Arts and Science) and evaluations (e.g., Female, Male). People are quicker to respond when items that are more closely related in their minds share the same button. For example, an implicit preference for Liberal Arts relative to Science means that you are faster at sorting words when 'Liberal Arts' and 'Female' share a button relative to when 'Science' and 'Female' share a button. If the initial response to a stimulus was incorrect, a red “X” would appear and remain on the screen until a participant selected the correct response, whereby latency was recorded in occurrence with the correct response. As for rs4680, the score of IAT showed that carriers of two COMT Met alleles (AA genotype) exhibited a stronger implicit stereotype than did the heterozygotes or the Val homozygotes (AG/GG genotype). In addition, individuals with two BDNF Val alleles (GG genotype) manifested a weaker implicit stereotype than did those with one or two BDNF Met alleles (AG/AA genotype). Scientists confirmed these findings in the replication sample.
These findings suggest that variants in the COMT and BDNF genes may contribute to the variation of gender–science stereotypes. However, scientists know that genes are just one factor contributing to the gender–science stereotype. For example, the environment is likely to play a big role. Future molecular genetic studies can address these questions by incorporating environmental measures (e.g., gender-dependent parenting or schooling). Read more about the study here: