Autism is characterized by persistent difficulties in social interaction and social cognition. These difficulties are partly related to atypical processing of socio-emotional signals, including emotional facial expressions. Although core autistic characteristics are observed in both males and females, increasing evidence suggests that autistic females often show a more subtle socio-emotional profile, marked by greater attention to social stimuli and more typical-appearing social behavior. However, this profile remains insufficiently characterized, and the underlying neurobiological mechanisms are still poorly understood.

Given the central role of face processing in social cognition, we conducted a series of behavioral and EEG studies to investigate sex differences in autism during face processing at different stages of attentional processing. Our results reveal sex-related differences in autism from early stages of face processing, with autistic females showing an intermediate profile between autistic males and non-autistic females. Together, these findings indicate that aggregating males and females may obscure meaningful neurocognitive differences in socio-emotional processing and highlight the need for sex-informed experimental designs and theoretical frameworks in autism research. They further suggest that early differences in socio-emotional processing may contribute to the subtler phenotypic presentation of autism in females.