Monetary sacrifice among strangers is mediated by endogenous oxytocin release after physical contact

Humans frequently sacrifice resources to help others—even strangers. The proximate mechanisms inducing such sacrifices are not well understood, and we hypothesized that touch might provoke a sacrifice of money to a stranger. We found that touch significantly elevated circulating oxytocin (OT) levels but only when it was followed by an intentional act of trust. Touch followed by trust increased monetary sacrifice by 243% relative to untouched controls. We also found that women were more susceptible than men to OT release and monetary sacrifice after touch. This suggests that touch draws on physiologic mechanisms that support cooperative behaviors in humans.