This article considers scientific evidence relevant to 4 claims that are often made about the findings of research that has compared the sexes. These claims are that the sex-related differences demonstrated by empirical research are small, unusually unstable across studies, very often artifactual, and inconsistent with the content of gender stereotypes. The empirical status of these claims has been seriously weakened by the findings of numerous quantitative syntheses of research that have compared female and male behavior. This weakening of the evidence has jeopardized the feminist political agenda of using empirical research to disconfirm gender stereotypes to raise women's status. Consequently, comparing the sexes has become increasingly controversial among psychologists. To deal responsibly with the issues that have been raised psychologists should consider the role that their research plays in discourse on the status of women in society.