To punish or to leave: distinct cognitive processes underlie partner control and partner choice behaviors

When a cooperative partner defects, at least two types of response are available: Punishment, aimed at modifying behavior, and ostracism, aimed at avoiding further social interaction with the partner. These options, termed partner control and partner choice, have been distinguished at behavioral and evolutionary levels. However, little work has compared their cognitive bases. Do these disparate behaviors depend on common processes of moral evaluation? Specifically, we assess whether they show identical patterns of dependence on two key dimensions of moral evaluation: A person's intentions, and the outcomes that they cause. We address this issue in a "trembling hand" economic game. In this game, an allocator divides a monetary stake between themselves and a responder based on a stochastic mechanism. This allows for dissociations between the allocator's intent and the actual outcome. Responders were either given the opportunity to punish or reward the allocator (partner control) or to switch to a different partner for a subsequent round of play (partner choice). Our results suggest that partner control and partner choice behaviors are supported by distinct underlying cognitive processes: Partner control exhibits greater sensitivity to the outcomes a partner causes, while partner choice is influenced almost exclusively by a partner's intentions. This cognitive dissociation can be understood in light of the unique adaptive functions of partner control and partner choice.