Pain perception during social interactions is modulated by self-related and moral contextual cues

Despite the growing interest on the effect of the social context on pain, whether and how different facets of interpersonal interactions modulate pain are still unclear. We tested whether personal (i.e., convenient for the self), moral (i.e., equitability of the transaction) or social (i.e., positive vs. negative feedback from others) valence of an interpersonal interaction differentially affects pain and the perceived fairness. Thirty-two healthy participants played the role of Receivers in a Dictator Game, where a player, the Dictator, determined how to divide a payoff between her/himself and the other player, the Receiver. We manipulated the payoff (pain vs. money), the personal valence (favorable vs. unfavorable offer to participants), the moral valence of the offer (from very iniquitous to equitable), and social valence of the Dictator (social acceptance vs. rejection). Moral and personal valence differentially modulated pain. Lower pain was elicited by iniquity, but also by favorable offers. Moreover, unfavorable offers in the economic game were rated as more unfair, whereas only very iniquitous offers elicited such ratings in the pain game, suggesting that participants valued when Dictators endured extra pain for their benefit. Together, we show that the valence of a social interaction at different levels can independently modulate pain and fairness perception.