The process of stopping bad habits is fundamentally different from forming new ones.

• Creating a habit requires encoding a new set of automatic behaviors: the brain learns causal relationships between triggers that prompt action and the associated outcome.
• The popular belief is that the key to breaking a bad habit is replacing it with another habit. But this doesn't always work.

The process of “progressive extremism” utilizes what we know about the psychology of identity to help stop behaviors we don’t want. It works particularly well in situations in which substituting one habit for another just won’t do.

Identity helps us make otherwise difficult choic...