This study examines the underrepresentation of women faculty in science, technology, engineering, and mathematics (STEM) by comparing the intentions of attrition and turnover between genders in Research and Doctoral universities. It is found that the two genders did not differ in their intentions to depart from academia, but women faculty had a significantly higher likelihood to change positions within academia. The indications are that women and men are equally committed to their academic careers in STEM; nonetheless, women's stronger turnover intentions are highly correlated with dissatisfaction with research support, advancement opportunities, and free expression of ideas. The findings suggest that the underrepresentation of women is more convincingly explained by an academic culture that provides women fewer opportunities, limited support, and inequity in leadership, rather than by gender-based differences such as roles in family responsibilities. Changes in academic STEM culture are needed in order to attract more women scientists and narrow the current gender gap.