Naturally disengaging control to reveal habits

Habits are an essential part of everyday decision-making, yet the mechanisms underlying human habit formation and expression are difficult to study in laboratory settings, where participants typically engage strong goal-directed (GD) control that can mask habitual tendencies. Recent approaches have successfully elicited habits in long experiments by limiting the amount of GD control participants can exert (e.g., through forced response times). We extend this approach by designing a short behavioral paradigm that aims to induce and reveal habits without extrinsically limiting GD control, instead incorporating task features that we hypothesized would encourage participants to spontaneously relax GD control: a hierarchical multi-step trial structure, opportunities for self-correction, and frequent switches between extensively and minimally practiced behaviors. Across seven experiments, we demonstrate that this approach induces habitual control in a relatively brief paradigm. Specifically, overtraining increases slips of action toward the extensively-practiced context and reduces slips toward the minimally-practiced one, indicating behavioral inflexibility at early response times, while slower responses remain dominated by GD control. The reliability of this overtraining effect depended on the inclusion of task features that we hypothesize encourage relaxed GD control. Beyond providing a practical, robust, and flexible tool for studying the cognitive processes underlying habit formation and expression, our paradigm expands the traditional stimulus-response conception of habits to include more complex, hierarchical behaviors that may better reflect naturalistic human habits.