Abstract
<p>Individual differences in the capacity to learn and control habits are central to current models of psychopathology, which assume an overreliance on habit behavior in transdiagnostic compulsivity. 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, 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, indicating trait-like habit learning and expression. Improvements in response time across learning were stable and correlated with habits, suggesting an early trait-like index of habitualization. Stable processes of habit formation were reflected during both habit acquisition and expression.</p>