Gender differences in the observation of gesture direction: a physiological study

Intransitive gestures are expressive and symbolic, whereas pantomimes are object-related actions. These gestures convey different meanings depending on whether they are directed toward (TB) or away from the body (AB). TB gestures express mental states (intransitive) or hygiene/nutritional activities (pantomime), while AB gestures modify the behaviour of the observer (intransitive) or demonstrate tool use with an object (pantomime). A substantial body of literature suggests that females exhibit stronger social cue processing compared to males. Considering the social significance of gestures, this study aimed to explore the physiological gender differences in the observation of AB and TB gestures. Pupil dilation and High Frequency Heart Rate Variability (HF-HRV) were measured in 54 participants (27 female) while observing TB and AB gestures. The Interpersonal Reactivity Index (IRI) and the Vicarious Distress Questionnaire (VDQ) were used to assess social-emotional processes. Results showed greater pupil dilation in females for TB gestures, but no significant gender differences for HF-HRV. Males showed a significant correlation between increased pupil dilation to both TB and AB gestures and empathy levels (IRI). The support scale of the VDQ correlated significantly with TB gestures in males. These findings provide insight into the neurobiological basis of gender differences in perceiving social gestures.