The herding hormone: oxytocin stimulates in-group conformity

Psychol Sci. 2012;23(11):1288-92. doi: 10.1177/0956797612446026. Epub 2012 Sep 18.


People often conform to others with whom they associate. Surprisingly, however, little is known about the possible hormonal mechanisms that may underlie in-group conformity. Here, we examined whether conformity toward one's in-group is altered by oxytocin, a neuropeptide often implicated in social behavior. After administration of either oxytocin or a placebo, participants were asked to provide attractiveness ratings of unfamiliar visual stimuli. While viewing each stimulus, participants were shown ratings of that stimulus provided by both in-group and out-group members. Results demonstrated that on trials in which the ratings of the in-group and out-group were incongruent, the ratings of participants given oxytocin conformed to the ratings of their in-group but not of their out-group. Participants given a placebo did not show this in-group bias. These findings indicate that administration of oxytocin can influence subjective preferences, and they support the view that oxytocin's effects on social behavior are context dependent.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Behavior / drug effects*
  • Double-Blind Method
  • Humans
  • Male
  • Oxytocics / pharmacology*
  • Oxytocin / pharmacology*
  • Social Behavior*
  • Social Conformity*
  • Young Adult


  • Oxytocics
  • Oxytocin