Vocal emotion expressions effects on cooperation behavior

Emotional expressions have been proposed to be important for regulating social interaction as they can serve as cues for behavioral intentions. The issue has been mainly addressed analyzing the effects of facial emotional expressions in cooperation behavior, but there are contradictory results regarding the impact of emotional expressions on that behavior, particularly regarding the effects of joy expressions. In the present study, we extend research on the influence of emotional expressions on cooperation using vocal emotional expressions and address methodological shortcomings of previous studies. Forty-eight participants were exposed to joy, anger, and neutral emotional expressions before taking part in the "Assurance Dilemma" task, where behavioral and judgment measures were obtained. Behavioral results constitute the first evidence that non-facial emotional expressions influence cooperation behavior in experimental games and suggest that specific emotional expressions may have different effects on cooperation. Judgment measures suggest that experience, in addition to emotional expressions, may also play a role in this context. Theoretical and methodological implications are discussed.