Culture moderates the relationship between self-control ability and free will beliefs in childhood.

We investigate individual, developmental, and cultural differences in self-control in relation to children's changing belief in "free will" - the possibility of acting against and inhibiting strong desires. In three studies, 4- to 8-year-olds in the U.S., China, Singapore, and Peru (N = 441) answered questions to gauge their belief in free will and completed a series of self-control and inhibitory control tasks. Children across all four cultures showed predictable age-related improvements in self-control, as well as changes in their free will beliefs. Cultural context played a role in the timing of these emerging free will beliefs: Singaporean and Peruvian children's beliefs changed at later ages than Chinese and U.S. children. Critically, culture moderated the link between self-control abilities and free will beliefs: Individual differences in self-control behaviors were linked to individual differences in free will beliefs in U.S. children, but not in children from China, Singapore or Peru. There was also evidence of a causal influence of self-control performance on free will beliefs in our U.S. sample. In Study 2, a randomly assigned group of U.S. 4- and 5-year-olds who failed at two self-control tasks showed reduced belief in free will, but a group of children who completed free will questions first did not show changes to self-control. Together these results suggest that culturally-acquired causal-explanatory frameworks for action, along with observations of one's own abilities, might influence children's emerging understanding of free will.