La méthode des groupes Mastermind a été définie par Napoleon Hill au début du 20ème siècle .
En voici une définition (en anglais):
Napoleon Hill’s definition
The concept of the “master mind alliance” was introduced by Napoleon Hill in his book from the 1920s, The Law of Success, and expanded upon in his 1930s book, Think And Grow Rich. While Napoleon Hill called it a “master mind alliance,” it’s been shortened and modernized to “mastermind group.” Mastermind groups have been around since the beginning of time. Even Benjamin Franklin belonged to such a group, which he called a Junto. But it was Napoleon Hill who explained it clearly and encouraged people to gather together in a structured, repeatable environment for the success of all. Napoleon Hill wrote about the mastermind group principle as:
“The coordination of knowledge and effort of two or more people, who work toward a definite purpose, in the spirit of harmony.”
He continues…
“No two minds ever come together without thereby creating a third, invisible intangible force, which may be likened to a third mind [the master mind].”
Source : What is a Mastermind Group? A Definition and tutorials • The Success Alliance