Abstract **Individual Differences in the “Watching Eyes” Effect and Real Cues of Observation** People who prefer to maximize their own gain (individualists) increase cooperation in response to being observed, whereas those who prefer equality in outcomes (prosocials) respond less strategically. We extended this research to investigate individual differences in responses to the “eyes effect”, where people increase cooperation in response to images of watching eyes. Participants classified in advance as prosocials did not vary their contributions in a dictator game according to observation. Individualists gave more money to their partner in public conditions, compared to the eye or control conditions (d = .26), although these results did not reach statistical significance. These findings suggest that individualists respond strategically to observation, but only under conditions of real observation and not in response to eyes, whereas prosocials are continuously cooperative even under anonymous conditions. Individual differences in strategic responses to reputational incentives are important for their implications in the evolution and maintenance of human cooperation.