This investigation examined the independent and joint effects of aptitude (gifted vs. normal) and achievement (underachiever vs. achiever) on assessments of the selfsystem in upper elementary-aged children. The gifted group was significantly higher than the average group on selfevaluations of competence, feelings of mastery, and preference for independent decision making. The average group reported a lower level of understanding than the gifted group about the reasons for success and failure outcomes and more anxiety about school-related events. Underachievers were significantly lower than achievers on selfevaluations of performance and higher on perceptions of internal control over success and failure outcomes.Achievers were higher on perceptions of control by powerful others over outcomes.With no attempt there can be no failure; with no failure no humiliation. So our self feeling in this world depends entirely on what we back ourselves to be and to do. (James, 1890, p. 313) William James was among the first to call attention to the significance of the relationship among aptitude, achievement, and the self-perceptions of an individual. Empirical researchers since James have attempted to delineate the various self-perceptions and feelings (which we shall refer to as component processes of the self-system) and their relationship to aptitude and achievement (e.g., see Burns, 1978;Purkey, 1967;Wylie, 1979;Harter, 1983, for reviews). For the most part, these studies convey the same messagedifferences in various components of the self-system are associated with differences in aptitude (ability) and academic achievement (effort). What previous studies lack, both individually and as a group, are domain specific and focused assessments of the individual components of the self-system and a model which explains the interrelationships among the components and their relationships to an individual's ability and effort in achievement related tasks.Recently, Connell (1981) and Harter and Connell (1984) have proposed a multi-component process model of the self-system and achievement within the academic domain. This model states that children's understanding of how to achieve leads to their achievement performances which are then evaluated by the self. These competence evaluations directly and indirectly influence (through their affective consequences) children's academic motivation. A recent review of the literature on the effects of aptitude and achievement on self-concept (Davis, 1984) confirmed that the constructs within the Connell model, along with general self-esteem, have been implicated as both causes and effects of aptitude and achievement in other studies.