(Hetero)sexual double standards (SDS) entail that different sexual behaviors are appropriate for men and women. This meta-analysis (k = 99; N = 123,343) tested predictions of evolutionary and biosocial theories regarding the existence of SDS in social cognitions. Databases were searched for studies examining attitudes or stereotypes regarding the sexual behaviors of men versus women. Studies assessing differences in evaluations, or expectations, of men’s and women’s sexual behavior yielded evidence for traditional SDS (d = 0.25). For men, frequent sexual activity was more expected, and evaluated more positively, than for women. Studies using Likert-type-scale questionnaires did not yield evidence of SDS (combined M = −0.09). Effects were moderated by level of gender equality in the country in which the study was conducted, SDS-operationalization (attitudes vs. stereotypes), questionnaire type, and sexual behavior type. Results are consistent with a hybrid model incorporating both evolutionary and sociocultural factors contributing to SDS.