The interactive mentalizing task. Children completed 24 trials of each condition (Peer Mental, Character Mental, Peer Non-Mental, Character Non-Mental) in an event-related design. Mental trials required reasoning about mental states, while Non-Mental trials did not. In the Peer trials, children believed they were interacting with a child being scanned in another laboratory, whereas in Character trials, they believed they were answering questions about a fictional character provided by a computer. All trials had predetermined peer or computer responses. A smiley face (Peer) or check mark (Character) in the Feedback period indicated a match between the child’s response and the peer or computer response.