Voice attractiveness affects cooperative behavior in the Stag Hunt Game: evidence from neural electrophysiology

The halo effect of attractiveness influences not only physical appearance but also vocal characteristics, impacting people's lives and behaviors. Previous research has shown that voice attractiveness may affect decision-making and social interactions, but its influence on cooperative behavior has not been thoroughly investigated.

This study used neurophysiological methods, specifically EEG, to examine the impact of voice attractiveness on cooperative behavior in the Stag Hunt Game. Participants played a two-person version of the game with a virtual partner whose voice was either highly attractive or less attractive. EEG data was recorded during the game, focusing on brain responses during the voice processing phase and outcome feedback phase.

The results revealed a "beauty premium" effect: participants were more likely to cooperate when paired with a highly attractive voice. Electrophysiological data showed that high-attractiveness voices elicited larger P2, P3, and LPC amplitudes and smaller theta oscillations during the voice processing phase. During the outcome feedback phase, both highly attractive voices and gain feedback resulted in smaller FRN amplitudes and larger P300 amplitudes. In contrast, under less attractive conditions, loss feedback triggered larger theta oscillations.

These findings suggest that voice attractiveness significantly influences cooperative behavior in social decision-making contexts. The neural responses indicate that the attractiveness of a voice can modulate both early sensory processing (P2, P3, LPC) and feedback evaluation (FRN, P300, theta). This study highlights the role of voice attractiveness in shaping cooperative behavior and provides new insights into the neurophysiological mechanisms underlying social decisions.