Objective: Habit-formation interventions may help individuals initiate and maintain behaviour change. This paper proposes and empirically tests the idea that it is possible for individuals to form 'higher-order habits', or behaviours that can be executed in more than one way, and still be habitual. Design: Participants (N = 82) were healthy adults randomly assigned to an action-and-coping-planning intervention for forming a 'higher-order habit' of filling half of their dinner plates with fruits and vegetables or a control condition. Key measures were collected at baseline and 1, 2 and 3 weeks post-baseline. Participants submitted 3 pictures per week of their dinner plates via snapchat/email. Main Outcome Measures: Intrinsic motivation, habit strength and behavioural frequency for filling half their dinner plates with fruits and vegetables. Results: Intervention participants reported significantly greater habit strength at each follow-up time point. Controls did show some degree of habit formation, despite not fully forming a habit. Behavioural automaticity increased despite consuming a variety of fruits/vegetables; results did not depend on participants' intrinsic motivation to consume fruits/vegetables. Conclusion: It may be possible for individuals to form 'higher-order' habits, which may be particularly important in health contexts, in which many target behaviours are complex and can be seen as higher-order.
Keywords: Habit formation; habit measurement; intrinsic motivation; planning intervention.