Gender Differences in Neurobehavioural Signatures of Interpersonal Negotiation Revealed by EEG Hyperscanning

Interpersonal negotiation is an essential component of social-economic interactions, yet the concept is not entirely gender-neutral. Male stereotypes — dominance, assertiveness, and rationality — help shape the negotiator role, giving men a perceived advantage in negotiations. This study adapts electroencephalogram hyperscanning and an iterated ultimatum game to investigate the gender differences in dyadic economic negotiation, focusing on event-related potentials and source-localized phase-locked interbrain synchronization (IBS). Behaviorally, dyads with male proposers (M-dyads) achieve better negotiation outcomes than dyads with female proposers (F-dyads) in goal-driven negotiation contexts, reflecting differences in negotiation strategies. Neurally, M-dyads exhibit lower P200 amplitude in the frontal cortex and significantly higher IBS within social brain networks, both of which are strongly associated with reciprocal negotiation behaviors. Notably, IBS between the temporoparietal junction (TPJ), medial prefrontal cortex (mPFC), and superior temporal sulcus (STS), alongside P200 amplitude, serves as a strong predictor of reciprocal behaviors, underscoring the role of TPJ, mPFC, and STS in interpersonal coordination. Moreover, significant mediation effects highlighted the bridging role of IBS between gender composition and negotiation outcomes. These findings provide neurobehavioral accounts of how dyad gender composition influences negotiation outcomes, suggesting that stronger IBS within key social brain regions underlies effective interpersonal coordination.