Research paper
Verplanken B, Sui J. Habit and Identity: Behavioral, Cognitive, Affective, and Motivational Facets of an Integrated Self. Frontiers in Psychology. 2019;10:1504. doi:10.3389/fpsyg.2019.01504. PMCID: PMC6635880.
Why we cite it
From the creator of the Self-Report Habit Index — a priority claim, and the checkable half of what this sentence used to assert; it previously read ”the most widely used habit measurement instrument”, a usage ranking nothing here measures (corrected 2026-09-02, card 6NM98H). This paper provides empirical evidence that habits become integrated into personal identity — but only when they connect to meaningful values or goals. Two studies demonstrate that the habit-identity link is not automatic; value affirmation significantly strengthens it. This supports the project’s emphasis on identity-based approaches to eating behavior change rather than pure willpower or behavior modification strategies.