Explaining behaviour is ubiquitous in our society. We are constantly trying to figure out what other people are doing and will do. This study is a comprehensive investigation of the main philosophical and psychological problems regarding how and why humans explain behaviour. The author answers key questions about how folk psychology develops in children, its roots in evolution, its status within society, its relation to philosophy of mind, and what sorts of folk psychological explanations should be considered rational. This assessment focuses on such theoretical positions as antirealism, eliminativism, theory-theory, simulation theory, and modular theory in relation to folk psychology. The author argues for a radical, albeit intuitive, alternative, that folk psychology should be seen as product of the culture in which one is raised.