It is commonly assumed that identification with a social group is constant throughout the play of a one-shot game in the absence of feedback. We provide evidence which challenges this assumption. We direct subjects to play one of two versions of the prisoner's dilemma game. These versions are distinguished by the relative attractiveness of the uncooperative action. We refer to the version with a relatively attractive uncooperative action as the Easy Game and the other as the Difficult Game. We find that for the subjects who play the Difficult Game, their change in group identification is significantly related to their action selected. No such relationship exists within the Easy Game. Additionally, we find that the change primarily occurs after the action is selected rather than upon inspection of the game. We discuss the implications of our findings to settings both inside and outside of the laboratory.