Temporal stability for individual differences in both habit learning and expression

Actions transition from goal-directed to stimulus-driven habits through repetition. Individual differences in the capacity to learn and control habits are central to current models of psychopathology, which assume that overreliance on habitual control drives maladaptive behaviors. However, whether these tendencies reflect stable, trait-like cognitive processes remains unclear. We examined the temporal stability of individual differences in habit learning and expression. Across two preregistered experiments (total N = 313), we assessed stimulus–response habits using the same stimuli after one day or different stimuli after four months. Evidence for stable individual differences in habit commissions was strong and comparable across experiments, with computational modelling further supporting trait-like tendencies for habit learning and expression. Trait-like tendencies were also reflected in action automatization while practicing stimulus-response associations, which was associated with future habitual behavior. Our findings have theoretical implications for our understanding of habit formation and its role in psychopathology.