Maxwell Maltz

Who they are

Maltz took his doctorate in medicine at the Columbia University College of Physicians and Surgeons in 1923 and trained further under German plastic surgeons. He wrote New Faces, New Futures in 1936 and Psycho-Cybernetics, published by Prentice-Hall in 1960, a book about self-image that combines Prescott Lecky's self-consistency work with the cybernetics of Norbert Wiener.

In it he described patients whose faces had been changed by surgery taking about three weeks to get used to the new appearance, and set this beside amputees who sensed a phantom limb for about the same period. From such observations he suggested that it takes a minimum of about 21 days for an old mental image to dissolve and a new one to form.

Three things were lost as the figure travelled. He wrote of a minimum, not an exact count. He was describing adjustment to a change, not the building of a routine. And the figure came from clinical impressions, not a measured study. When Phillippa Lally's team measured habit formation, automaticity plateaued after an average of 66 days.

Key papers

Maltz, M. (1960). Psycho-Cybernetics: A New Way to Get More Living out of Life. Prentice-Hall.

Maltz, M. (1936). New Faces, New Futures: Rebuilding Character With Plastic Surgery.

Key ideas

See The Twenty-One Day Myth.

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