A Big Fat Crisis (5 page)

Self-control has been closely tied to health, well-being, and general success in life. This association has led multiple researchers to investigate its development over the life cycle. Obviously, a newborn lacks self-control entirely. But when does self-control start to develop? And why do some people have more than others? Is it a consequence of one’s upbringing?

A couple of recent scientific studies point to early childhood for the onset of self-control failure. In one study, Drs. Lori Francis and Elizabeth Susman, professors at Penn State University, followed more than one thousand children from age three to twelve.
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At ages three and five, they tested the children’s capacity for self-control. In the first test at age three, the children were shown how much fun it is to play with Ski Boat Croc, a small plastic toy boat on wheels with a crocodile at the steering wheel pulling another crocodile behind on water skis.
After spending a few minutes pulling the toy back and forth, the children were told not to touch the toy or play with it while the interviewer left the room for about two and a half minutes. However, the children were allowed to play with other toys in the room instead. Children who couldn’t wait more than seventy-five seconds before touching the Ski Boat Croc toy failed the test. Forty-five percent failed.

In a second test, the same children at age five were asked to pick their favorite snack from among three choices: M&M’s, animal crackers, and pretzels. Then a small pile and a large pile of that snack were placed in front of the children. If the children wanted to eat the snack right away, they could have the small pile. But if they could wait three and a half minutes, they could get the large pile. Again, nearly 45 percent failed to wait. Only 36 percent were able to wait long enough at ages three and five to pass both tests of self-control. By age twelve, those who had failed both tests had higher rates of weight gain than those who had passed both.

Another long-term study looking at the relationship between the early capacity for self-control and obesity weighed and measured 805 children at age four. In this study the researchers didn’t directly test the children’s ability to restrain themselves, but instead asked their mothers how well they thought their children would be able to delay gratification. The children of mothers who reported that they were unable to delay gratification at age four had a 29 percent increased risk of being overweight by age eleven.
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What do these studies suggest? In every case the researchers claim the implications are that we need to work harder to teach our children better self-control at an early age or they will become out-of-control adults. But how hard would parents need to work? What would they have to do?

Would parents have to adopt the strict child-rearing methods advocated by Amy Chua in her book
Battle Hymn of the Tiger Mother
? Do we need rigid schedules and routines, vigilantly limiting the foods we bring home, controlling where our children dine out, and cautiously planning each and every calorie they consume?

Two experts in child development and obesity, Drs. Leann Birch and Jennifer Fisher, suggest the opposite. Attempts to restrict and control
children’s eating appear to exacerbate the problems of self-control, poor diet, and obesity.
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If parents force their children to eat fruits and vegetables and constantly say no to foods high in sugar and fat, children learn to value these forbidden foods and hate fruits and vegetables.
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A study that followed girls from age seven to fifteen supported this observation. At seven, the girls were asked about parental restrictiveness with food. “If you ask for a snack, does Mommy let you have it?” By fifteen, girls who had earlier said their parents were more restrictive became heavier than those who had said their parents were more permissive. The implication is that children may be better able to learn self-control when parents do not closely monitor them but allow them to make unfettered choices. (Of course, the researchers caution that unhealthy foods should only be available in limited quantities.)

These studies seem to point to misguided child-rearing practices as a potentially important contributor to obesity. But could child-rearing practices be responsible for adult obesity? Most adults become overweight well after they reach adulthood. People typically gain weight gradually, over decades, with the average American gaining only one to two pounds per year. While child-rearing practices may matter, they probably only contribute to a very small fraction of the obesity epidemic.

Another concept closely related to self-control is “executive functioning,” also called “executive capacity,” which represents our ability to make wise choices. These terms are largely used in the fields of neuroscience and psychology. Executive functioning abilities develop as we mature, and they have been shown to be closely related to how much self-control we have as children.

A long-term study investigating the trajectory of self-control followed 946 twins.
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Given that some of the twins were identical (monozygotic), meaning they shared the exact same genetic material, and the rest were fraternal (dizygotic), genetically different, it was possible for the researchers to distinguish between factors that appeared to be inherited and those that were the result of child-rearing practices.

When the twins were toddlers, at fourteen, twenty, twenty-four, and thirty-six months, they were challenged with a self-restraint test to avoid touching a glitter wand for at least thirty seconds. Later, at ages sixteen and seventeen the same twins were given a barrage of tests to
study their executive functioning. Just as in the previous studies, the youth who showed more self-control as children had higher executive functioning in late adolescence.

While the researchers found that absolute levels of self-control increased with development, the children’s relative abilities to restrain themselves were fairly stable over time. Because the identical twins were more similar in their capacity for self-control than the dizygotic/fraternal twins, genetics were deemed primarily responsible for self-control and executive functioning, a finding that contradicted the popular belief that the aptitude for self-control was chiefly due to training.

Many psychologists believe that within limits, the overall capacity for people to restrain themselves is a permanent, relatively irremediable trait. An individual can improve to a degree, but someone who has been born with genes associated with low self-control will never be able to develop the capacity for self-control of someone who was endowed with more favorable genes.

A long-term follow-up of ninety-two four-year-old children followed over forty years lends substantial support to the conclusion that self-control is a stable trait that doesn’t change over time.
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The study was initiated in the 1970s, when the four-year-olds participated in tests of their ability to delay gratification (by resisting a marshmallow). There are cute videos on YouTube showing how some of the kids handled the challenge.
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Some were able to withstand the temptation by covering their eyes, while others were not so successful and surreptitiously licked the marshmallow or took tiny bites.

Later, as adults in their twenties and thirties, they were again tested on self-control abilities. Those who had lower self-control at age four also performed poorly as adults, and similarly, those with higher self-control as children performed better. Recently, nearly sixty of these ninety-two individuals, now in their forties, were called back again, and this time, they underwent brain scans as they participated in another self-control experiment.
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A different part of the brain was activated among the group with lower self-control than among those with higher self-control, suggesting that the brains of those with high
and low self-control are wired differently. This finding signifies important differences in brain functioning that may not be easily changed.

Accepting that we might not be able to substantially increase our self-control abilities may be difficult, whether or not we personally have trouble controlling our weight. Most of us don’t see ourselves as limited. After all, there are so many self-help books that promise we can improve ourselves in every area of self-control—from anger management to reducing procrastination. Why would we bother to make New Year’s resolutions if we didn’t believe we could follow through?

When it comes to eating, we don’t see ourselves as automatons being hypnotized by food cues and unable to refuse. And we have the experience of making our own decisions. We think we understand ourselves, and we have the sense that we really can control ourselves if we want to.

The capacity for self-control seems to depend on what has to be resisted. People have trouble inhibiting themselves only when they would otherwise want to engage in a particular behavior. But eating is one of those universal behaviors that is challenging to most people’s capacity for self-control, regardless of how well they might score on scientific tests of executive capacity.

We typically think of self-control as an internal struggle that we have to fight within ourselves. If there is no struggle, then we don’t think we are using any self-control. For some, controlling the consumption of all foods may be a challenge, while for others, only particular foods may be difficult to resist. If you dislike apple pie, then you don’t have to use any self-control to prevent yourself from eating it. On the other hand, if you hate vegetables, then it would take a great deal of self-control to make yourself eat them.

Dr. Wilhelm Hofmann, an Assistant Professor of Behavioral Science at the University of Chicago, specializes in the study of self-control. He recently conducted a study to try to understand how often people have problems with self-control. He recruited 206 adults and asked them to carry a BlackBerry with them fourteen hours a day, for seven consecutive days. The BlackBerries were programmed to prompt participants to answer questions at least seven times a day about their
desires, the strength of their desires, and whether they tried to resist acting on these desires.
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Hofmann found that, in general, the participants felt some kind of desire or want during half their waking hours. About 28 percent of the time, they said they wanted to eat. Next, about 10 percent of the time, they wanted to sleep. After that, about 9 percent of the time, they just wanted something to drink other than coffee or alcohol. Coffee was desired 3 percent of the time, and alcohol another 3 percent of the time. Not surprisingly, the participants only wanted to engage in sports or exercise 2.6 percent of the time. Thus, the desire to eat occurred more than ten times as often as the desire to exercise.

Furthermore, when people desired something, about half the time these desires came into direct conflict with other goals, values, or motivations. Maybe they wanted to sleep or relax, for example, but they were at the office and had to work. Yet when there was no feeling of conflict and they wanted to do something, such as write a thank-you note or practice playing a musical instrument, people were only able to follow through and do what they desired about 70 percent of the time. But when there was a conflict and they would have preferred not to do something, like smoke a cigarette or have a drink, they failed to control themselves, on average, one out of every six times. Self-control was worst when it came to media activities, like watching television or using the computer. About 42 percent of the time, they failed to turn off the power buttons when they knew they should have been doing something else. They failed to control their eating nearly 25 percent of the time. However, they had little trouble resisting sports participation, sexual urges, or the desire to spend money. The study also showed that within a given day, the more people tried to resist an urge, the lower their ability to control themselves as time went on.

You might be able to pass on the drinks and appetizers, and pick a healthy entrée, but when the dessert cart rolls in, all bets are off.

Self-Control Fatigues Like a Muscle

In the 1990s social psychologist Roy Baumeister and his colleagues conducted several studies on self-control. They were the first to note
that self-control tends to deteriorate over time, in the same way a muscle fatigues with repeated exertion. One of their studies showed the consequence of resisting available food.

Three groups of people were asked to participate in a taste perception test. All groups were told to skip a meal before the experiment and to make sure they had not eaten for at least three hours. The laboratory room had a display of freshly baked chocolate chip cookies and chocolate candies and another display of red and white radishes. The first group was assigned to taste the cookies and candies. The second group was assigned to taste the radishes, and was specifically told not to eat any of the cookies or candies, which were meant for the first group. The participants who tasted the radishes were asked to eat at least two or three. Similarly, those assigned to the treats were asked to eat at least two or three cookies or a handful of the small candies. Both groups were asked to wait at least fifteen minutes to allow the sensory memory of the food to fade and at the same time to do an unrelated problem-solving task. A third group (the control group) did not have to wait in the room with the food displays, and was asked to work on the problem-solving task right away. The researchers then looked at how well the three groups did with the problem-solving task.
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The group with no food in the waiting room worked the longest in trying to solve the puzzle, an average of twenty-one minutes. The group that was allowed to eat the cookies and candy gave up after nineteen minutes, while the group that had to refuse the treats gave up after eight minutes. Why did they give up so quickly? “I was tired” and “I didn’t feel like it” were the common responses. No one in the group was able to see a connection between having to use a lot of energy to resist the lure of the cookies and the rapidity with which they tired in their subsequent task.