The so-called optimism bias may get in the way of a healthy lifestyle.
Yes, media messages about nutrition are often confusing and inconsistent, but many Americans know what is considered a healthy diet. I mean, does anyone really think drinking brown carbonated sugar water is good for them? The issue is that they don’t appear to be translating their knowledge into action.
Why do people have such difficulty changing their dietary behaviors? While ignorance and confusion may play a part, being motivated to change is likely much more important. Certainly, we are living in a world that pushes us to eat whatever we want, regardless of the long-term consequences. “One of the major problems in getting people to change their behaviour is the need to get them to recognise the need to change.”
For example, if you ask people how much meat they eat—or how much greasy food, eggs, sweets, alcohol, or butter—they claim to be eating less than the average person. So, if people think they’re at less risk than others, they may dismiss advice to eat more healthfully, thinking that they already eat healthier. Is it possible that they actually are? No, people rated their own eating behavior as healthier on average, even when their actual eating habits were terrible. Because of this, perhaps campaigns promoting health need to make people aware of how badly they are eating. But when that is done, a strange thing happens. When people are challenged with the reality of what the average person actually eats, they change their answer to make themselves appear as though they’re still healthier than average.
When people’s positive comparisons on risky behaviors are threatened, they tend to not only reduce their estimates of how frequently they engage in those behaviors—”oh, I don’t eat that much meat”—but they also minimize the significance of the behaviors. “Meat’s not that bad for you anyway.” It’s the same “personal fable” that smokers tell themselves. Studies show that smokers have a strong tendency to underestimate smoking-related risks, developing a series of illusions and false beliefs to support their choice to keep smoking.
Why do so many people continue to light up in spite of smoking’s harm to their health? For many of the same reasons, people continue to eat unhealthy food. First, they convince themselves that they are less at risk than others who engage in the same behavior. Adding to this optimism bias, smokers also underestimate how much smoking elevates lung cancer risk, thinking two-pack-a-day smokers only have five times the risk of getting lung cancer when their actual risk is 20-fold higher, as you can see below and at 3:10 in my video Why Don’t People Eat Healthier?.
Also, many smokers believe lung cancer is mainly determined by genetics.
Many hazards related to the food we eat share this same “optimistic bias,” like heart attacks and heart disease (our number one killer), obesity, diabetes, and all the rest. People can often find quite ingenious reasons for believing that their own risk is less than others’ risk. So, maybe public health advocates need to be just as ingenious in understanding where this unrealistic optimism originated from and find ways to help people gain a more accurate picture of their own vulnerability. All sorts of work is being done trying to reduce or eliminate this bias, “but we must consider the possibility that reductions in optimistic bias might lead to reductions in self-esteem and psychological well-being,” if people start to realize just how much risk they truly face and how much they have themselves to blame.
This reminds me of the tightrope wire health professionals have to walk, telling people how much power we all have over getting cancer. There is an oft-cited paper that calculated that we may be able to prevent approximately 90% of human cancers. Although its reference to “present trends” referred to the 1960s—when this paper was published—it still applies today, more than half a century later. “Genetic factors are not the major causes of chronic diseases.” Using identical twins to see how much disease risk was truly genetic, researchers found that out of 28 chronic diseases, cancers had the lowest genetic component—only about 10% attributable to bad genes. What runs in families is bad habits.
But when you tell everyone the good news about how much power we have in preventing cancer, what about the people who already have it? When people are diagnosed with cancer, they often ask, “Why me? Did I do something wrong? Is this my fault?” So, you can imagine how the message of “well, yeah, kinda” could be destructive for patients or survivors. In other words, a message that is intended to empower people and promote prevention could just make cancer victims feel guilty.
But the truth is still the truth, no matter how difficult it may be. So, what doctors have to do is try to guide patients to “switch from guilt feelings to a ‘responsibility’ approach.” They have personal control; they can make different choices from now on. Doctors need to give them a sense of agency in their lives. Better, though, to try to take those steps before you get cancer.
Doctor’s Note
For more on personal responsibility, see Why You Should Care About Nutrition and Taking Personal Responsibility for Your Health.
