Body size estimation: Discrimination of subtle differences in male and female body parts

Abstract

The study determined the sensitivity of adults to detect subtle differences in male and female body parts (face, arms, chest, waist, hips, thighs and calves). A total of 202 adults (84 men and 118 women) with a mean age of 34.9 years adjusted the size of each part of a comparison silhouette until it matched that of a sample silhouette. The sensitivity to detect subtle differences was greater for the male than for the female silhouette (mean Weber Fractions, WF=.032, .036, respectively). The greatest sensitivity for both silhouettes was in the waist and hips (WF=.019 in both cases) and the smallest in the arms and face (WF=.048, .049, respectively). Men, young participants and those with high education (WF between .017 and .043) detected subtle differences to a greater degree than their counterparts (WF between .019 and .053). According to the environmental approach of social psychology, the latter suggests that members of those subgroups have been subjected to more social pressures to sharpen their discrimination of small differences in the body shape of their conspecifics. This study adds evidence to previous knowledge about how cultural variables shape visual perception.