It's a fifty-year old test that is so famous that advertising agencies have used it to promote retirement plans. Parents of little children use it to try and guess how well their progeny are going to do in life. And now it is out in a book, called (surprise, surprise) The Marshmallow Test.
The inventor, psychology professor Walter Mischel, used it on 600+ privileged children in California. Each child was led into a room, and seated at a table. Before him or her was a plate holding a single marshmallow. He or she was told that if the marshmallow was still there when the supervisor came back, the reward would be a second marshmallow.
In a word, it was an exercise in self-control, and the penalty for instant gratification. Most children ate the marshmallow the instant he or she was left alone, but about a third went into contortions rather than "fail" the test. So, the following video is not just very amusing, but also educational.
Even more interestingly, the professor and his colleagues followed the careers of the children, and found that those who had been able to exert self-control were more successful in life. It won't be a surprise that they were leaner and fitter, but they were also better scholars and had good private lives too, managing to make good choices in friendships, marriages, and avoid the pitfalls of drugs adn crime.
But were there flaws and slip-ups in the research process? What did it really tell the world about the value of self control? This very interesting interview with Professor Mischel reveals a great deal.