Infants rationally decide when and how to deploy effort

The ability to decide whether, when and how to try is central to human learning. We investigated whether infants can make rational inferences about when and how to try on a novel problem-solving task. After learning from an adult that the task was either easy, difficult or impossible to solve, infants varied in whether, when and how they tried based on the type of social evidence that they received and on their own ongoing experience with the task. Specifically, infants formed expectations about the task, their own ability to solve the task and the experimenter's ability to solve the task, in light of accumulating evidence across time that impacted their time spent trying, trying force, affect, and help-seeking behaviour on the task. Thus, infants flexibly integrate social input and first-hand experience in a dynamic fashion to engage in adaptive persistence.