The purpose of this study was to determine whether the manifestation of extraversion (i.e., acting and being extraverted) in everyday behavior can be explained by intentional (functional) constructs, namely, goals. By using a model in which personality states serve as an outcome of specific, momentary goal pursuit, we were able to identify the function of extraversion states in everyday behavior. Using experience-sampling methodology, we asked participants to describe their state extraversion, goal pursuit, and state affect over 10 days. Results show that 18 selected goals predicted 74% of the variance in state extraversion; both within-person and between-person fluctuations in state extraversion were strongly associated with changes in momentary goal pursuit. We extended findings relating state extraversion and state positive affect, showing that the relationship between goals and positive affect was partially mediated by state extraversion.