Eye Cues Increase Cooperation in the Dictator Game under Physical Attendance of a Recipient, but Not for All

A growing body of research has demonstrated that images of watchful eyes can promote prosocial behavior in a variety of settings. However, studies on the impact of eye cues on prosocial behavior in economic games yield ambiguous findings and thus provide no clear answer to the question whether these nudges have the potential to cause significant behavioral change. Moreover, the underlying mechanisms of watchful eyes remain unclear. We investigate whether cues of being watched positively affect prosocial behavior in the dictator game when a recipient is physically present. In a post-experimental questionnaire, we gathered additional information on attitudes towards trust and voluntary cooperation and on emotional responses to eye images. The weak effect observed in our study suggests that images of human eyes may increase cooperative behavior in the dictator game, providing support for the idea that the ‘watchful eyes effect’ is caused by a concern for avoiding bad reputation. Individual differences in attitudes towards trust and voluntary cooperation did not account for this effect. Furthermore, data from our post-experimental questionnaire provided mixed support for the theory that the watchful eyes effect may ultimately stem from higher levels of negative emotions related to the feeling of being watched caused by the exposure to human eye images. While we found no difference in the positive or negative affect schedule (PANAS) related to eye images and flowers after a long exposure during the experiment, participants in the control group associated lower levels of pleasure and a more dominant feeling (SAM) with the eye images after a short exposure to both stimuli. Referring to a relatively large variability of cooperativeness among participants in the eyes condition, we need to interpret the weak watchful eyes effect cautiously and conclude that eye cues do not make people more cooperative and prosocial across the board.