White Bears, Dieting, and the Rebound Effect
The real question about how to avoid overeating is not how to strengthen your ability to restrain it, but how to avoid ricocheting from dieting to bingeing and back again. I’ll explain that soon, but first let’s do a little exercise. Ready? Don’t think about white bears. Seriously, don’t think about them for about a minute, and then take another minute to just let your mind wander without any restrictions. Go ahead, I’ll wait.
Okay, time’s up.
Let me try to describe what just happened in your mind, if you were actually trying this. First, in order to follow the instruction not to think about them, you had to conjure up an image of a white bear. Then, you were probably pretty successful blocking most white bear thoughts or images for that minute. Then, when you relaxed and allowed yourself to think about whatever you wanted, you thought a lot about white bears, at least a lot more than you usually do.
This is a very simplified version of a classic series of experiments, known as the white bear studies, done by psychologist Daniel Wegner beginning in the 1980s. One group was instructed to describe whatever they were thinking for five minutes but to try not to think of a white bear and to ring a bell every time they did. After that, they were again told to hit the bell when they said or thought about white bears, but this time they were told they should try to think about them. When they were given that instruction, they had a lot more white bear thoughts than a control group that was given the same directions in reverse order – first do, then don’t. What’s interesting to me, and relevant to our topic, is that after you stop trying to block out the image, there’s that rebound of the thought you had been trying to suppress.
Clearly, the phenomenon that Wegner demonstrates in his studies is not the reemergence of some deep-seated need to think about white bears once you’re allowed to; more likely, it’s simply a reaction against having been told not to think about them in the first place. What’s the motivation? We’re motivated to be free of external control. When that freedom is suppressed, even briefly, our minds respond with a need to counteract that loss of control, even if it’s over something insignificant, like suppressing a thought. Because it’s not about the thought, it’s about autonomy – independent control over your own choices and behavior.
This need for autonomous control, as I’ve written in an earlier post, has been explained by two psychologists at the University of Rochester, Richard Ryan and Edward Deci. According to this idea, called self-determination theory, this feeling of autonomy is a basic human need. It isn’t learned by observation or taught through instruction. Infants have the ability to communicate their preferences through a variety of behaviors. This need to be in charge of having one’s own needs met is one of those modules of the mind that presumably evolved because it is adaptive for survival. It allows us to get our needs met when we feel it’s necessary; like the need to get fed, be warm, or have pain attended to quickly, before the need becomes a threat.
This relates to the idea that emotional eating is a response to the perception of being controlled. The subjects in the white bear studies had a “need” to think about something that they had no reason to think about other than as a reaction to being told they couldn’t think about it. In the same way, we have a tendency to do things like eat when we don’t really need or even want to, simply because we feel it’s prohibited and we have an opportunity to reassert our need not to be controlled.
Now think about what happens when you’re on a diet. Those volunteers had to keep the image of the white bear in mind in order to avoid thinking about it. It’s like a forest ranger on the lookout for brush fires: he’s got to think about the image of the very thing he doesn’t want to see! That’s what happens when you diet. You have to keep in mind what you can’t eat while you’re on the diet. Then when you’re off the diet those thoughts you’ve suppressed rebound with a vengeance, but now you don’t have to restrict yourself.
It may seem counterintuitive, but it’s solid logic: if you can eliminate that self-imposed decree against eating what you want, you’ll eliminate the desire to violate it. You’ll be making the choice because you really want to eat, not just because you can. Think about the end of prohibition or the new marijuana laws in Colorado and Washington. No one feels compelled to break a rule that no longer exists.