On average, women make up half of introductory-level philosophy courses, but only one-third of upper-division courses. We contribute to the growing literature on this problem by reporting the striking results of our study at the University of Oklahoma. We found that two attitudes are especially strong predictors of whether women are likely to continue in philosophy: feeling similar to the kinds of people who become philosophers, and enjoying philosophical puzzles and issues. In a regression analysis, they account for 63% of (...) variance. Importantly, women are significantly less likely to hold these attitudes than men. Thus, instructors who care about improving the retention of women undergraduates should find ways to improve these attitudes – for instance, by demonstrating the ways in which professional philosophers are like them. We will discuss some tentative but intuitively plausible suggestions for interventions, though further research is required to establish the effectiveness of those interventions. (shrink)