It turns out that a scientist can see the future by watching four-year-olds interact with a marshmallow. The researcher invites the children, one by one, into a plain room and begins the gentle torment. You can have this marshmallow right now, he says. But if you wait while I run an errand, you can have two marshmallows when I get back. And then he leaves.
Some children grab for the treat the minute he's out the door. Some last a few minutes before they give in. But others are determined to wait. They cover their eyes; they put their heads down; they sing to themselves; they try to play games or even fall asleep. When the researcher returns, he gives these children their hard-earned marshmallows. And then, science waits for them to grow up.
By the time the children reach high school, something remarkable has happened. A survey of the children's parents and teachers found that those who as four-year-olds had the fortitude to hold out for the second marshmallow generally grew up to be better adjusted, more popular, adventurous, confident and dependable teenagers. The children who gave in to temptation early on were more likely to be lonely, easily frustrated and stubborn. They buckled under stress and shied away from challenges. And when some of the students in the two groups took the Scholastic Aptitude Test, the kids who had held out longer scored an average of 210 points higher.
When we think of brilliance we see Einstein, deep-eyed, woolly haired, a thinking machine with skin and mismatched socks. High achievers, we imagine, were wired for greatness from birth. But then you have to wonder why, over time, natural talent seems to ignite in some people and dim in others. This is where the marshmallows come in. It seems that the ability to delay gratification is a master skill, a triumph of the reasoning brain over the impulsive one. It is a sign, in short, of emotional intelligence. And it doesn't show up on an IQ test.
For most of this century, scientists have worshipped the hardware of the brain and the software of the mind; the messy powers of the heart were left to the poets. But cognitive theory could simply not explain the questions we wonder about most: why some people just seem to have a gift for living well; why the smartest kid in the class will probably not end up the richest; why we like some people virtually on sight and distrust others; why some people remain buoyant in the face of troubles that would sink a less resilient soul. What qualities of the mind or spirit, in short, determine who succeeds?