We study how individuals' contribution to a team production task varies depending on whether the task is ego relevant or not. We design and conduct an experiment to test the effect of ego-relevance in two types of team tasks: when contributions are complementary and substitutable. Ego-relevance is manipulated by calling the Raven IQ Test an “IQ Task” or a “Pattern Task”. We find that the effects of ego-relevance are mediated by beliefs about the teammate's contributions. Subjects act as conditional cooperators. However, the pessimistic ones contribute even less in the Ego-relevant condition, whereas the optimistic ones contribute more in the Ego-relevant condition. We do not find the nature of team production process being complementary or substitutable moderating the effect of ego-relevance on contribution decisions.