In this research, the authors examined the development of intentional self-regulation in early adolescence, which was operationalized through the use of a measure derived from the model of selection, optimization, and compensation (SOC). This model describes the individual's contributions to mutually influential relations between the person and his or her context. Through use of data from a longitudinal sample of 5th and 6th graders who were participating in the 4-H Study of Positive Youth Development (PYD), structural equation modeling procedure, reliability analyses, and assessments of convergent, divergent, and predictive validity suggested that a global, 9-item form of the SOC measure was a valid index of intentional self-regulation in early adolescence. Scores for this index of SOC were related to indicators of positive and negative development in predicted directions. The authors discuss the idea that self-regulation is a global process in early adolescence that contributes to PYD.