Identity-based habits are James Clear’s approach to lasting change: instead of aiming at an outcome, you decide the kind of person you want to be and let each habit serve as a vote for that identity. The direction runs from belief to behavior to result, the reverse of outcome-based habits, which start from what you want to achieve. Clear holds that behavior conflicting with self-image rarely lasts, so the most durable lever is to change the identity beneath a habit. The vault links this to its brain-science thread, where identity forms beneath conscious thought and lasting change comes through repeated experience.

Wikipedia: Atomic Habits