Responding to controversies about the balance between nature and culture in determining human sexuality, the author proposes that the female sex drive is more malleable than the male in response to sociocultural and situational factors. A large assortment of evidence supports 3 predictions based on the hypothesis of female erotic plasticity: (a) Individual women will exhibit more variation across time than men in sexual behavior, (b) female sexuality will exhibit larger effects than male in response to most specific sociocultural variables, and (c) sexual attitude-behavior consistency will be lower for women than men. Several possible explanations for female erotic plasticity are reviewed, including adaptation to superior male political and physical power, the centrality of female change (from no to yes) as a prerequisite for intercourse, and the idea that women have a milder sex drive than men.