The experimental study presented in Cox et al. (1991) referred to henceforth as CLM, revealed that culture has a substantial impact on the cooperative or non-cooperative behavior of U.S.- born African, Anglo, Asian and Hispanic Americans in a Prisoner's Dilemma setting. The present article complements CLM's study in three ways. First, CLM's experiment is replicated with a sample of Dutch undergraduates. This replication confirms the major finding of the CLM study that culture matters. Second, the role of uncertainty is included by introducing two different information regimes, indicating that uncertainty regarding the opponent's future behavior facilitates cooperation. Third, CLM's study is extended by analyzing the influence of education - particularly, knowledge of the competition or game theory of economics. It is found that knowledge of behavioral theories or "soft" economics does stimulate cooperative behavior, but that it has no impact on opportunism. The first point supports the claim in Holler et al. (1992) and Frank et al. (1993) that education plays a role in determining the cooperative or non-cooperative attitudes among managers and students, while the second underscores CLM's observation that culture does matter.