Evidence for the dynamic human ability to judge another's sex from ambiguous or unfamiliar signals

Humans make decisions about social information efficiently, despite - or perhaps because of - the sheer scale of data available. Of these various signals, sex cues are vitally important, yet understanding whether participants perceive them as static or dynamic is unknown. The present study addressed the related question of how expertise impinges on sex judgements. Participants were asked to target female and male exemplars from a set of own- or other-race hand images. Data show: (1) that the own-race sex categorisation advantage observed previously using face stimuli can occur in relation to hands, and (2) sensitivity of Asian participants, but not Caucasian participants, is dynamic relative to how many fe/males there are in a set. Implications of these findings are discussed as further evidence that there exists a pan-stimulus sex processor, and as fresh evidence that human sex perception can change probabilistically.