Put a marshmallow in front of a preschooler. Tell them if they wait 5 minutes to eat it they'll get a second marshmallow. Walk away.
A test just like this was conducted 40 years ago with marshmallow and cookies to study delayed gratification in children. Now, researchers have followed up with the same then preschool-age test subjects and found that a higher propensity for delayed gratification was carried on to adulthood.
Watch a more recent video of children enduring the struggle during the marshmallow experiment. It's harder than it looks when that marshmallow is staring you in the face:
The follow up, published by the National Academy of Sciences, found that the same children who could resist the marshmallow before, had similar willpower today. According to the release (via Science Daily):
Those better at delaying gratification as children remained so as adults; likewise, those who wanted their cookie right away as children were more likely to seek instant gratification as adults. Furthermore, brain imaging showed key differences between the two groups in two areas: the prefrontal cortex and the ventral striatum.
. . .
"This is the first time we have located the specific brain areas related to delayed gratification. This could have major implications in the treatment of obesity and addictions," says lead author Dr. B.J. Casey, director of the Sackler Institute for Developmental Psychobiology at Weill Cornell Medical College and the Sackler Professor of Developmental Psychobiology.
The second time around the 59 participants from 40 years before didn't get a marshmallow -- apparently cookies and marshmallows are "less rewarding for adults." Instead the participants, looked at a screen with a series of faces. They signaled only when a face of a certain gender was shown; this test was a control. It showed no significant differences between the two groups. The second test -- the "hot" test -- showed emotional faces on a screen. Results were varied and revealed that delayed gratification was consistent from childhood to adulthood:
"In this test, a happy face took the place of the marshmallow. The positive social cue interfered with the low delayer's ability to suppress his or her actions," explains Dr. Casey.
The original marshmallow and cookies test was conducted by Walter Mischel, a co-author of the current study and the Niven Professor of Humane Letters at Columbia University.