Researchers follow up on an old study:
Between 1968 and 1974, about 650 4-year-olds in a nursery school at Stanford were offered a selection of marshmallows, cookies, and pretzels. After they chose one (let’s say it was the marshmallow, though I’d have picked a cookie myself), they were told they could either eat it immediately, or wait a few minutes and get two. The researcher giving the kids this choice then left the room.
Now in their 30s, the kids who were able to delay gratification for longer turn out to be better off in a number of ways.