The 21-day myth began as a misinterpretation of Dr. Maxwell Maltz’s work on self-image. Maltz did not find that 21 days of task completion forms a habit.

Snap-Back Effect is a term coined by Dr. Maxwell Maltz, author of “Psycho-Cybernetics,” to describe the rampant self-sabotage of personal improvement goals.

The initial 21 days idea is thought to have come from Maxwell Maltz's self-help book, Psycho Cybernetics: It usually requires a minimum of about 21 days to effect any perceptible change in a ...

It was once believed that a habit forms after 21 consecutive days—a notion popularized by surgeon and writer Maxwell Maltz in “ Psycho-Cybernetics: A New Way to Get More Living Out of Life. ” Despite ...