Abstract
Parties to conflict and to exchange interactions typically experience a considerable uncertainty as to the intentions and strategic plans of their adversaries. Such uncertainty is threatening and can therefore elicit competitive responses. Perceived control over an adversary's actions and over the course of an interaction can reduce uncertainty, lower the perceived risk of exploitation, and thus facilitate cooperative responses. This mediating role of perceived control was demonstrated in two experiments. They showed that certain patterns of change in one party's strategy enhanced the other party's perception of control and, concurrently, increased the frequency of its cooperative responses. A third experiment showed that variations in perceived control affect the tendency to cooperate, even if such variations are not directly related to or induced by the adversary's strategy.