Evidence is accumulating that infants are sensitive to people's false beliefs, whereas children pass the standard false belief test at around 4 years of age. Debate currently centres on the nature of early and late understanding. We defend the view that early sensitivity to false beliefs shown in ‘online tasks’ (where engagement with ongoing events reflects an expectation of what will happen without a judgement that it will happen) reflects implicit/unconscious social knowledge of lawful regularities. The traditional false belief task requires explicit consideration of the agent's subjective perspective on his reasons for action. This requires an intentional switch of perspectives not possible before 4 years of age as evidenced by correlations between the false belief task and many different perspective-taking tasks.