Abstract
Habitual actions are elicited automatically in associated settings, bypassing conscious motivation. This has prompted interest in habit formation as a mechanism for sustaining behaviour change when conscious motivation erodes. Promoting habit depends on understanding how habit develops. This chapter reviews theory and evidence around the habit formation process. First, we describe the few, recent studies that have explicitly sought to study habit development for meaningful activities in humans. Next, we outline a framework for understanding the habit formation process, and narratively review evidence regarding the factors that may directly facilitate or impede habit development, generating hypotheses for future studies. We offer practical suggestions for optimal modelling of habit formation and its determinants.