Perceiving sociosexuality: how is it done?

People make judgements about personal characteristics (including age, sex, attractiveness, health and personality) from strangers' face and body appearance, and from small snippets of behaviour. These perceptions are thought to be somewhat accurate. Previous research has suggested that people are able to accurately perceive sociosexuality (SOI) at zero acquaintance, however it is not clear what cues people are using to make these accurate judgements. Further research has established a link between body morphology (2D:4D ratio) and SOI score, but it is not known whether facial morphology, which is also influenced by in utero hormones, is associated with SOI. Thus, the focus of this study was to examine whether: a) SOI is reflected in facial morphology, and b) whether observers can accurately perceive SOI from these facial cues. In Study One, 123 participants (63 female) completed a version of the SOI and had facial photographs taken under standardized conditions. Geometric morphometric methodology was used to statistically quantify the variation in face shape of each participant. This produced a significant model producing self-reported SOI scores from facial shape in male, but not female, faces, suggesting that SOI is reflected in men's, but not women's facial morphology. In Study Two, 65 participants (45 female) rated the SOI of participants photographed in Study One and a series of composites. Geometric morphometric modelling provided a statistical model that significantly predicted perceived SOI from the facial morphology of males but not females. Significant correlations between perceived SOI and self-reported SOI, and between self-reported SOI scores and perceived SOI scores predicted by the statistical model, were found in male faces but not female faces. Female participants appear to be able to accurately perceive the SOI of men using facial shape. Future studies should investigate other potential cues to SOI, such as colour or texture.