Despite efforts to promote gender diversity in STEM, math-based STEM majors, such as Engineering, Computer science and Physics, remain male dominated. In this research, the effects of peer interactions are examined within students in math-based STEM majors, since peer relationships significantly impact retention and success in STEM. However, underrepresented groups, such as women in STEM, are particularly susceptible to negative stereotypes about their group, through the induction of stereotype threat. This study seeks to investigate how the gender of the support-giver and support-seeker in a peer directed study group affect male dominated STEM majors’ personal wellbeing, social perceptions and STEM-related outcomes using video vignettes of an interaction in a study group. The gender of the support-giver, as depicted in the vignette, influenced social perceptions and to a lesser extent, STEM-related outcomes. Likewise, female participants scored lower in personal wellbeing, social perceptions and STEM-related outcomes, which were consistent with literature about stereotype threat. Implications of these findings and future research directions are discussed.