Intellectual giftedness is culturally associated with men rather than women. I will describe a line of research that investigates the acquisition and the consequences of this “brilliance = men” stereotype. With respect to acquisition, I will present evidence that, by the age of 6, girls are already less likely than boys to believe that members of their gender are “really, really smart.” Next, I will document two consequences of this stereotype. First, the idea that brilliance is a male trait undermines girls’ and women’s interest in activities that are believed to require a high level of intellectual ability. Second, this stereotype gives rise to biases against girls and women in contexts where brilliance is seen as important. These findings speak to the early acquisition of cultural beliefs about brilliance and gender, and to the potential role of these stereotyped notions in creating and sustaining gender inequities in career outcomes.