Two important sources of information for social judgments are personality dispositions (traits) and social norms. Existing research suggests that young children do not find traits salient. To what extent might they rely on a different source of information? Two experiments explored how information about preferences (what someone likes) and rules (what is allowed or forbidden) affected social judgments. Five-year-olds predicted people's future behavior would be consistent with rules, but appeared insensitive to information about preferences. Preferences were better predictors than rules for 8-year-olds. Older children and adults consistently judged that actors would want to, and be happy to, satisfy preferences rather than rules. Younger children were more likely to use rules to infer people's psychological states. Results are consistent with the hypothesis that deontic relations, such as rules and norms play a central role in young children's social cognition, with ideas of individual psychological dispositions emerging in middle childhood.