Sex Differences in Overhand Throwing are Completely Due to Socialization: A Blank Slate “Hypothesis” Unconstrained by Evidence

Contemporary evolutionary biology–including evolutionary psychology–assumes an interactionist framework, recognizing the importance of both biological (nature) and environmental (nurture) influences. Despite this scientific consensus, within women’s studies and gender studies, socialization-only explanations of sex differences in behavior persist. This commentary evaluates a recent prominent example: Anne Fausto-Sterling’s 2025 critique of our 2018 Quarterly Review of Biology thesis that the large human sex difference in overhand throwing partly reflects an evolved male adaptation. Fausto-Sterling (FS) argues that our ancestral selection scenarios are unrealistic and that, based on a qualitative study of ten infants, childhood throwing differences are fully explained by early socialization. We demonstrate that FS’s critique fails in several ways. First, FS’s objections about our evolutionary scenarios rely on flawed characterizations of the hunter-gatherer literature, ignoring our primary focus on ancestral combat and discounting cross-cultural data showing far greater male involvement in hunting. Second, FS erroneously implies that childhood throwing performance is our sole evidence, ignoring extensive data presented on elite athletic performance, cross-cultural consistency, prenatal hormone exposure, and distinct skeletal sexual dimorphisms. Finally, FS treats evolutionary and developmental processes as mutually exclusive, failing to recognize that evolutionary theory predicts that socialization will often mediate and amplify evolved behavioral predispositions. We conclude that the persistence of FS’s socialization-only, Blank Slate perspective can only be maintained by ignoring relevant evidence.