Willpower

Turner, one of the rare actors to make a good living in Hollywood, they can succeed in the most difficult endeavors. But they do face above-average challenges, particularly if they don’t monitor themselves carefully. Researchers testing personality have found that diabetics tend to be more impulsive and have more explosive temperaments than other people their age. They’re more likely to get distracted while working on a time-consuming task. They have more problems with alcohol abuse, anxiety, and depression. In hospitals and other institutions, diabetics throw more tantrums than other patients. In everyday life, stressful conditions seem to be harder on diabetics. Coping with stress typically takes self-control, and that’s difficult if your body isn’t providing your brain with enough fuel.
    Jim Turner deals with his self-control problems directly—and hilariously—in a one-man show titled “Diabetes: My Struggles with Jim Turner.” He recalls moments like the argument with his teenage son that ended with him, ostensibly the adult, getting so mad that he went outside and kicked a permanent dent into the family car. “There are many times,” Turner says, “when my son can see that I am not in control, when he has to force me to drink some juice, when he is afraid that I am just not there.”
    Turner doesn’t use any version of the Twinkie defense to excuse the dent, and he doesn’t feel sorry for himself, either. On the whole, he keeps his diabetes under control, and says the disease hasn’t stopped him from being happy and fulfilling his dreams (except for that one about teleportation). But he also recognizes the emotional consequences of glucose. “There are so many little moments of connection that I have missed,” he says, “that I wasn’t available to my son because I was busy dealing with a low-blood-sugar episode and too overwhelmed trying to figure out what was going on. It’s the single biggest heartbreak of this disease.”
    What exactly happens to Turner during those moments? You can’t draw definitive conclusions from any anecdote or even from the large studies showing above-average problems with self-control among diabetics and other groups of people. Correlation is not causation. In social science, the strongest conclusions are permitted only when researchers use experiments that randomly assign people among different treatment conditions, so that individual differences even out. Some people arrive at the experiment happier than others, or more aggressive, or more preoccupied and distracted. There is no way to guarantee that the average person in one experimental condition is the same as the average person in another experimental condition, except by counting on the law of averages. If the researchers randomly assign people among treatment and control groups, the differences tend to average out.
    For example, if you wanted to test the effects of glucose on aggression, you would have to consider that some people are already aggressive while others are peaceful and gentle. To show that glucose caused the aggressiveness, you’d want about an equal number of aggressive people in the glucose and in the no-glucose conditions, and also equal numbers of pacifists. Random assignment usually does this pretty well. Once you’ve got representative groups of people, you can see how they’re affected by different treatments.
    Nutritionists used this method during food experiments at elementary schools. All the children in a class were told to skip breakfast one morning, and then, by random assignment, half of the children were given a good breakfast at school. The others got nothing. During the first part of the morning, the children who got breakfast learned more and misbehaved less (as judged by monitors who didn’t know which children had eaten). Then, after all the students were given a healthy snack in the middle of the morning, the differences disappeared as if by magic.
    The magic ingredient was isolated in other experiments by measuring glucose levels in people before and after doing simple tasks, like watching a video in which a series of words flashed at the bottom of the screen. Some people were told to ignore the words; others were free to relax and watch however they wanted. Afterward, glucose levels were measured again, and there was a big difference: Levels remained constant in the relaxed viewers but dropped significantly in the people who’d been trying to avoid the words.