Sex differences in blushing and eye contact in mixed versus same-sex dyads

It is commonly assumed that women blush more strongly than men, but sex differences in blushing have been identified in only a few studies and what underlies these differences has not been explored. Hence, the aim of this study was to investigate factors that might underlie sex differences in blushing. To monitor blushing, changes in pulse amplitude in the forehead skin were measured in 40 male and 40 female participants during stressful laboratory tasks (serial subtractions and singing). A male or female experimenter interacted with participants during these tasks in a critical or friendly manner. In addition to blushing, the effect of these manipulations on gaze aversion (a nonverbal cue of embarrassment) was explored. Blushing was greater in women than men and was greater in participants tested by a male than female experimenter. However, neither the sex-composition of experimenter-participant dyads nor the interpersonal style of the experimenter modified blushing intensity, despite effects on eye contact. These findings suggest that sex-linked influences on autonomic reactivity rather than embarrassment moderate blushing during social interactions. These sex-linked influences may be important during cognitive-behavioural treatments for social anxiety associated with fear of blushing.