Friendship networks predict girls' STEM fit and interest through subjective belonging.

Girls report lower belonging in STEM (science, technology, engineering, mathematics) than boys, which may carry costs for girls' later STEM participation. We hypothesized that being socially included within a STEM context supports feelings of belonging-which then contributes to stronger intentions to pursue STEM, especially for girls. To investigate, we recruited girls and boys (N = 1,330; Mdn age = 12; 41% White, 35% East Asian) attending week-long Canadian STEM summer camps. We gathered precamp and postcamp STEM intentions (fit and interest), plus postcamp objective social inclusion and subjective belonging (with distinct metrics computed for female vs. male peers). Consistent with previous findings, girls had lower STEM intentions than boys. In addition, we found that, for girls, being more socially included (particularly by male peers) was associated with stronger STEM intentions, mediated by subjective belonging. For boys, social inclusion (via belonging) was less predictive of STEM intentions. These results highlight how childhood friendships may impact early intentions to pursue STEM education and careers, especially for girls.