Oxytocin, but not vasopressin, increases both parochial and universal altruism
Israel S et al. – The authors find that oxytocin causes an increase in both the willingness to cooperate and the expectation that others will cooperate at both levels. In contrast, participants receiving vasopressin did not differ from those receiving placebo in their cooperative behavior. The results highlight the selective role of oxytocin in intergroup cooperative behavior.