The present study was designed to investigate the development of children's trait explanations and self-evaluations in the 2 domains. 144 white, middle-class children in kindergarten, first, second, and fourth grades (mean ages 5-8, 7-0, 7-9, and 10-0 years, respectively) were interviewed individually about their explanations for both academic and social outcomes and their evaluations of their own outcomes. Trait explanations emerged earlier in the social domain. In addition, trait explanations emerged earlier for success than for failure. Self-evaluations became less positive in both domains and less similar across domains with increasing grade level. An experiential theory of the development of understanding of a domain is presented.