The article presents an empirical research which aimed at verifying if participation in a cooperation or competition training determined future behaviors during an anonymous, two-person trust game. We applied two variants of training: active and passive. The main hypothesis claimed that participation in a cooperation training activates the social norm of cooperation and induces more cooperative choices in trust games, whereas participation in a competition training reduces the willingness for cooperative choices. We also predicted that an active training would be more effective in activating cooperation and competition norms than a passive one. Finally, it was expected that interrelation of a cooperative decision in a more risky game would reduce the influence of a training-activated norm on the final decision. The results of the experiment confirmed all three hypotheses.