Psychological theory of social cognition and Buddhist philosophy of cognition suggest that people's actions should determine their impressions of future events. In psychology, several studies have shown that behavior can activate constructs and thereby influence one's perception. However, they do not address prosocial behavior, a specific concern of Buddhist philosophy and the theory of karma. Two experiments examined the ability of prosocial behavior to influence perceptions of other people using a single round prisoner's dilemma game (PD). In the first study, cooperative (prosocial) behavior in the PD was manipulated by first priming undergraduate psychology student participants with selfless or selfish thoughts through a paragraph-reading task. PD game and priming control conditions were included. After the PD game, participants read a description of a target person that was ambiguously relevant to prosocial traits. Then they rated the target on fourteen positive, neutral or negative personality traits that were either related or unrelated to the primed construct, cooperativeness. As predicted, compared to those who competed, cooperators in the
PD rated the target significantly higher on the four positive valence traits related to cooperativeness. Due to inadequate manipulation of cooperative behavior, results of experiment 1 provided only correlational support for the hypothesis. When this limitation was addressed in experiment 2, trends in the data suggested support for the hypothesis but results failed to reach significance. Methodological limitations of the current work as well as directions for future research are discussed.