We explored how students' endorsements of essential (biological and personality) and constructed (socialization and contextual) explanations for gender differences changed from the start to the end of Psychology of Women (POW) classes along with their feminist attitudes. Results from surveys of 120 POW students from three universities indicated that these students began class with more feminist awareness, immersion, and constructionist thinking than 228 general students, and that constructionist thinking was associated with perceptions that gender differences can be eliminated. Students' essentialism declined across their POW class, whereas their constructionist thinking increased and their feminist attitudes strengthened. End-of-semester feminist identification was associated with stronger endorsement of contextual explanations for gender differences above and beyond initial identification. We discuss implications for researchers, instructors, and activists.