The social psychophysics of cooperation: Nonverbal communication in a public goods game

An experiment was conducted to test the hypothesis that cooperation in a social dilemma context could be facilitated by inducing participants to emit "social psychophysical" cues, information in the perceptual array that affords meaningful and consequential social inferences. In particular, participants were asked to engage in mutual eye gaze, to touch one another gently, to communicate in a virtual chat room, or to tap out rhythms in synchrony. All but the last of these manipulations increased contributions to a public good in all-male but not all-female groups. These results suggest the inference systems that are engaged when individuals make decisions about whether or not to cooperate in a group context are responsive to relatively low level nonverbal behavioral cues.