Many longitudinal studies on job attitudes have been performed during the period of socialization, which arguably covers the first two years on the job. In this chapter, we evaluate the temporal development of organizational commitment during socialization by performing a meta-analysis of longitudinal studies. This allows us to evaluate whether job attitudes grow, decline, or remain stable during this sensitive, novice period. Additionally, it allows us to evaluate when such purported change sets in and whether it stabilizes. Although our results are not without limitations due to researchers’ inconsistent use of time intervals, the results reveal significantly declining trajectories between 3 and 12 months after entry and relatively low heterogeneity between studies in that period. Between 0–3 and 12–24 months, we found no significantly declining trajectories and higher heterogeneity between studies. The results underline the precariousness and dynamism of the person–organization relationship during socialization.