Oxytocin has been proposed to regulate human trust. Previous experiments supported this claim by demonstrating that exogenous and endogenous oxytocin is associated with trust (how much trust people place in strangers) and reciprocity (how much people reciprocate when trusted). However, recent...

In this article we introduce a new experimental game called Prisoner’s Dilemma with Variable Dependence (PD/D), which allows players to separate their trust in their exchange partners from their cooperation with them in an ongoing relationship. The game allows researchers to observe the...

One of the key scientific challenges is the puzzle of human cooperation. Why do people cooperate? Why do people help strangers, even sometimes at a major cost to themselves? Why do people want to punish others who violate norms and undermine collective interests? Reward and punishment is a...

Shame is often considered a moral emotion with action tendencies shaped by natural selection to elicit socially beneficial behavior. Yet, unlike guilt or other social emotions, prior experimental studies do not indicate that incidental shame boosts prosocial behavior. Based on the affect as...

"Social preferences" have repeatedly been shown to be sensitive to subtle cues of interdependence in many social exchange type-situations. The Ultimatum Game is one such exchange which is assumed to measure preferences for "fairness." The current experiment tests if cueing interdependence...