Oxytocin amplifies the influence of good intentions on social judgments

Studies have shown that the evolutionarily conserved neuropeptide oxytocin (OT) promotes various prosocial behaviors, yet there are few studies of the effect of OT on social judgments, especially on judgments when the actor's intention and the final outcome are incongruent. In a double-blind, placebo-controlled experiment, participants were asked to play the role of the recipient in a dictator game and to make social judgments about the dictator after intranasal OT administration. To isolate the outcome and the intention of the dictator's allocation, we developed a novel social judgment task in which recipients were told that 50% of the dictators' proposals would be reversed. The results showed that the effect of OT on social judgment was modulated by intention: OT increased goodness ratings only towards dictators with hyperfair intention. Our findings support the affiliative-motivation theory which states that OT enhances the affiliative motivation and recognition of positive-valence social stimuli.