Oxytocin makes us trusting but not gullible

Abstract

Originally known for its role in childbirth and lactation, oxytocin (OT) has recently proved to play a key role in social behavior. Deprived of OT, humans are unable to recognize and to bond to their peers. Inversely, once boosted with OT, people become more caring, trusting and generous. Effect-sizes on trust and generosity were sufficiently large that OT started to be perceived as a natural drug that would make people credulous. But could OT really impede judgment and lead individuals to trust untrustworthy peers? Here we show that oxytocin makes people trusting, but not gullible. Namely, OT did not have a trust-enhancing effect on people who interacted with seemingly unreliable peers. These results emphasize that the effect of OT is much more context-dependent than previously thought. This finding therefore invalidates some of the potential commercial or military applications of oxytocin.