Abstract

Baron-Cohen's extreme male brain theory proposes that autism results from elevated prenatal testosterone levels. In the present study, we assessed possible correlated effects of androgen exposure on adult morphology and, in particular, the development of facial features associated with masculinity. We created composite images capturing statistical regularities in facial appearance associated with high and low Autism-Spectrum Quotient (AQ) scores. In three experiments, we assessed correlations between perceived facial masculinity and AQ scores. In Experiment 1, observers selected the high-AQ males as more masculine. We replicated this result in Experiment 2, using different photographs, composite-image methods, and observers. There was no association of masculinity and AQ scores for female faces in either study. In Experiment 3, we created high- and low-AQ male composites from the five AQ subscales. High-AQ images were rated more masculine on each of the subscales. We discuss these findings with respect to the organizational-activational hypothesis of testosterone activity during development.