This article summarizes research on stereotypes about (the ways people learn in) STEM and (approaches to learning shown by) girls. STEM subjects are perceived as unfeminine or masculine subjects, and typical persons from STEM fields are perceived as lacking femininity. Math in particular is almost mythicized as a subject in which only ability and giftedness can lead to understanding and success, whereas effort and hard work are not sufficient. These stereotypes about STEM are contrasted with stereotypical beliefs about girls’ characteristics and typical “feminine” ways of studying. The psychological consequences resulting from this misfit between stereotypes about STEM and stereotypes of girls are then illustrated by the Interests as Identity Regulation Model (Kessels & Hannover, 2004; 2007; Kessels, Heyder, Latsch & Hannover, 2014). Empirical evidence, which has primarily been based on the self-to-prototype matching paradigm, has revealed the high relevance of individual perceptions of fit between a student’s (gender-related) self-concept and the stereotypes about STEM with regard to whether a student will actually like or choose to study a STEM subject. Finally, ways to bridge the gap are discussed within this framework.