Following the major paradigm shift from group selection to gene selection, game theoretical approach came into the study of animal behaviour as a powerful tool. Vast aspects of animal beheaviour are thought to be under one or other kind of game situation, and under those circumstances, evolutionary game theory often predicts the coexistence of more than 2 different strategies in one population. Evolutionarily Stable Strategy is the key concept to understand those situations. Game theoretical approaches have played an important role in the study of animal conflict, communication, cooperation, habitat selection, etc. In traditional game theory which are used in social sciences, strategies are assumed to be adopted by rational choice. In evolutionary game theory, each strategy has a genetic basis and the outcome of the competition among them are determined through natural selection. In the analysis of human behaviour, it is not yet clear what is the basic adaptive architecture of the workings of our brain and how cultural contexts insert influence on them. Nor are we yet successful to give full scientific explanation to the origin and maintenance of different types of cultures. However, evolutionary game theory makes a host of testable predictions about human behavioural diversity. It will be productive both for behavioural ecology and human social sciences to reconsider human behaviour from the evolutionary perspective.