Return of the lost letter: Experimental framing does not enhance altruism in an everyday context

Debate surrounds interpretation of prosocial behavior in experimental games. Skeptics of the thesis that evolution produced a propensity for noncontingent altruism speculate that such results reflect the presence of information suggesting reputational consequences, including awareness that one is participating in an experiment. To examine the effects on prosocial behavior of awareness that research is being conducted, return rates were measured on ‘lost’ envelopes, some of which carried the message that they were dropped as part of an investigation. Return rates were not enhanced by such messages, indicating that awareness that one is in an experiment does not increase prosocial behavior.