Thinking Cap is about work in progress in the world of ideas.
“Behavioral and neural correlates of delay of gratiﬁcation 40 years later” by B. J. Casey, Walter Mischel and 12 other collaborators in the Proceedings of the National Academy of Sciences. Dr. Casey is director of the Sackler Institute for Developmental Psychobiology at Weill Cornell Medical College, and Dr. Mischel, a psychologist, is Niven Professor of Humane Letters at Columbia University.
The Experiment: For nearly four decades the marshmallow test has fascinated researchers, educators and parents. In this famous experiment Dr. Mischel probed four-year-olds’ self-control by offering them one marshmallow now or two 15 minutes later. When Dr. Mischel caught up with the preschoolers years later, those who exhibited more self-control in the experiment turned out to be less likely to abuse drugs, and more successful in relationships, work, and handling stress as adults than their eat-it-now counterparts. Dr. Mischel, Dr. Casey, the lead author, and their team of collaborators wanted to take a closer look at just what was happening in the brains of these subjects.
They rounded up 59 of the more than 500 original participants — now in their mid-40s — to retake the test, and then scanned the brains of 26 of them using functional magnetic resonance imaging. Dr. Mischel had proposed that a “cool” system rooted in the conscious control circuitry in the brain and a “hot” system centered in the region devoted to desire and emotions were both involved in self-control. The question was whether people who quickly grabbed for the marshmallow — the “low delayers” — would have less activity in the right prefrontal cortex (cognitive control) and more in the ventral striatum (where positive rewards are processed), compared with the “high delayers.” Aware that sweets might not be as much of a lure to adults, Dr. Casey used happy, neutral and fearful faces to stand in for positive and negative social cues in order to examine the neural networks used in delaying gratification.
The Results: As in the earlier experiments, the researchers found that the children who were less able to resist temptation at 4 years of age were also less able to damp down their positive response to the happy faces 40 years later. More interesting was that the prefrontal cortex of the high delayers was in full swing during the trial while the low delayers showed an uptick in activity in the ventral striatum — an area also linked to addiction. The more alluring the object, the tougher it was for an individual “to suppress thoughts and actions, such that control systems may be ‘hijacked’ ” by the brain’s emotional responses. “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,” Dr. Casey said.
She did note, however, that while the resisters were better at exercising their willpower and systematically plotting out how to get more in the long run, the tendency to gratify desires more immediately was not necessarily a negative trait. They could be more likely to be “explorers, risk takers, pioneers.”
What do you think? Is it possible to develop and improve your self-control? Would you rather have a marshmallow or a smiley face? Post a comment below.