The aim of this study is to investigate whether there is a developmental difference in recognizing acts of harm through action and inaction (commission and omission). Thirty-nine children who were 4- to 6-year-olds judged tasks with acts of commission or acts of omission based on first-order mental states. Participants were more likely to give correct responses to mental state questions and incorrect ones to moral judgment questions than the reverse pattern. However, the difference between commissions or omissions did not significantly affect the correct responses in any age group. These results suggest that there are no developmental differences in recognizing acts of commissions and omissions based on the understanding of mental states.

Key words: harm through action (commission), harm through inaction (omission), first-order mental states, young children