Perception of human face does not induce cooperation in darkness

Abstract

Many studies showed that a concern to maintaining good reputation induces cooperation. Haley & Fessler (2005) found that an illustration of a human face makes people cooperative in the dictator game. We demonstrate that this effect is moderated by a particular contextual variable – darkness. We found that the illustration of a human face did not increase an amount of donation in the dictator game when it was presented in a dark sound proof room. In darkness, an observer often has a hard time in monitoring an actor even when an actor can see an observer. Hence, we conjecture that the human face-like stimuli does not increase a concern to reputation when presented in darkness, because the risk of an observer to identify the actor is low. Current experimental results show a possibility that a system that makes people cooperative in response to cues indicating the presence of the others is triggered only in a specific condition.