Abstract: | This article studies proactive work behavior from a within-person perspective. Building on the broaden-and-build model and the mood-as-information approach, we hypothesized that negative trait affect and positive state affect predict the relative time spent on proactive behavior. Furthermore, based on self-determination theory we argued that persons want to feel competent and that proactive behavior is one way to experience competence. In an experience-sampling study, 52 employees responded to surveys 3 times a day for 5 days. Hierarchical linear modeling confirmed the hypotheses on trait and state affect. Analyses furthermore showed that although a higher level of experienced competence at core task activities was associated with a subsequent increase in time spent on these activities, low experienced competence predicted an increase in time spent on proactive behavior. |