This paper explores three arguments. First, cultural accommodation by living in another culture for a while may have a long-lasting but partially dormant influence on behavior. Second, foreign language is a prime, activating behavior associated with this language. Third, a foreign language is expected to be a particularly forceful prime for those who have lived in a country where this language is spoken. We explore this logic in a prisoner’s dilemma quasi-experiment that focuses on competitive versus cooperative behavior.Testing our predictions with 358 Dutch students, we found that previous exposure to an Anglophone culture with higher values for masculinity, performance orientation and assertiveness negatively influences cooperative behavior in a prisoner’s dilemma game when the game is played in English.