In 1972, Walter Mischel brought children one by one into a room and gave them marshmallows. The doors were locked. The windows were unidirectional.
No, Mischel was not a pedophile. He was a psychologist and this would prove to be one of the most famous experiments of the last century.
Mischel, W., Ebbesen, E. B., & Raskoff Zeiss, A. (1972). Cognitive and attentional mechanisms in delay of gratification. Journal of Personality and Social Psychology, 21(2), 204–218.
Each child was put in a room by themselves and given a single treat. He then told the child that he had to leave the room, but if the child waited and didn’t eat the marshmallow until he came back, he would reward them with two marshmallows.
While outside the room, he tracked what the children did. Could they delay gratification and wait for a greater reward? Or would they indulge their impulses once left unsupervised?
About a third of the children immediately ate the marshmallow as soon as Mischel walked out. Another third waited for a period of time, but finally gave in and ate it. And then the last third waited the full 15 minutes — no doubt an eternity for …