Facing humanness: Facial width-to-height ratio predicts ascriptions of humanity

The ascription of mind to others is central to social cognition. Most research on the ascription of mind has focused on motivated, top-down processes. The current work provides novel evidence that facial width-to-height ratio (fWHR) serves as a bottom-up perceptual signal of humanness. Using a range of well-validated operational definitions of humanness, we provide evidence across five studies that target faces with relatively greater fWHR are seen as less than fully human compared to their relatively lower fWHR counterparts. We then present two ancillary studies exploring whether the fWHR-to-humanness link is mediated by previously established fWHR-trait links in the literature. Finally, three additional studies extend this fWHR-humanness link beyond measurements of humanness, demonstrating that the fWHR-humanness link has consequences for downstream social judgments including the sorts of crimes people are perceived to be guilty of and the social tasks for which they seem helpful. In short, we provide evidence for the hypothesis that individuals with relatively greater facial width-to-height ratio are routinely denied sophisticated, humanlike minds.