The role of personality in social interaction perception: an ERP and source imaging study

Agreeableness, one of the five personality traits, is associated with socio-cognitive abilities. This study investigates how agreeableness impacts the perception of social interactions, while considering sex that might moderate this effect. Sixty-two young adults, preselected to ensure a wide range of agreeableness scores, underwent EEG recording while viewing images depicting real-world scenes of two people either engaged in a social interaction or acting independently. Behavioral results suggested a trend where higher agreeableness scores predicted better ability to detect social interactions primarily in males. ERP analysis showed that individuals with higher agreeableness exhibited stronger neural differentiation between social and non-social stimuli, observed in both females and males, and in the whole sample. This neural differentiation, occurring early in the processing timeline, was particularly extensive in males, and predictive of their performance. Three independent source analyses, conducted for the whole sample and for each sex, identified the engagement of right fronto-parietal regions for the ERP-agreeableness association. These findings enhance our understanding of how agreeableness shapes the neural mechanisms underlying social interaction detection and emphasize sex as an important factor in this dynamic. They also highlight the need for tailored approaches that consider personality traits and sex in clinical interventions targeting social impairments.