I realized how far out of hand things had gotten the day my 4-year-old daughter came home from preschool with news that one of her friends had been out sick the last few days. Oh, that's a shame, my wife and I said. Our daughter leaned forward, and in a concerned voice confided, "I think it's stress."
Thus, we have science interpreted by a 4-year-old. And she's not alone in drawing such a conclusion: Stress has become the default explanation for a wide range of human conditions.
One triumph of 20th century medicine was lengthening the human life span. Whereas people used to die relatively young from the likes of flu, smallpox or childbirth, we've made huge advances in prevention and treatment. Now more people live long enough to develop and die of diseases of lifestyle, such as heart disease or diabetes. With that transition has come the vital recognition that stress of one kind or another plays a role in these modern diseases. This is a subject I've spent 30 years studying.
But while recognizing the role stress plays has been an important step forward, it has also caused people to greatly overestimate the importance of the stress/health link.
I thought about this most recently last week when that renowned scientist and candidate for U.S. Senate, Rep. Todd Akin, put his foot in his mouth. A staunch opponent of abortion, including abortion for pregnancies caused by rape, he made the argument that in cases of "legitimate rape," women would feel enough stress to shut down their ability to get pregnant. There is just enough truth in this to be dangerous. Yes, stress and trauma can disrupt reproduction, and yes rape is a hugely stressful trauma. But his conclusion couldn't be more wrong.
Stress can indeed disrupt aspects of reproduction, but it requires chronic stress to impair reproduction, and even then, the effects are mild. One example comes from a World War II study of women in concentration camps (raising a problem for stress scientists, which is whether and how to cite research carried out by inhuman Nazi doctors). Despite malnutrition, depression, illness, forced labor and constant permeating terror, about half the women studied were still ovulating. Reproduction is a biological locomotive, and only rarely does stress stop it in its tracks. That was a flaw in Akin's reasoning.
The same problem pertains to a more benign example, namely infertility. For families trying to conceive, infertility is a huge stressor. Not only do they have to face the possibility that they'll be denied one of the greatest potential sources of happiness in life, their lives are also turned upside down. Making love becomes an unsuccessful medical procedure; family gatherings become painful reminders of what isn't happening. And the high-tech medical procedures to address infertility, such as in vitro fertilization, are expensive, grueling procedures with no guarantee of success. The final insult, though, is the advice that almost invariably comes — from a friend, a relative, even a doctor: "Remember, you must relax as much as possible — after all, stress can prevent pregnancy."
It happens with cancer too. As if a diagnosis weren't enough to deal with, cancer patients are almost certain to be advised by someone along the way that stress can cause cancer, or bring it out of remission, or accelerate the growth of tumors. In one study I read, women with breast cancer were asked what they thought had caused their cancer, and stress was the most common explanation offered.
It's true that stress reduction (usually in the form of social support) can make it easier for cancer patients to adhere to brutal treatment protocols. But despite a lot of attempts to establish a link between stress and cancer, very few studies have found one, and the science suggesting that stress and cancer go hand in hand is often quite flawed.
One problem with this pervasive misunderstanding of the role of stress is what it suggests to those who have cancer or infertility or, in the wake of Akin's comments, to those who have been raped. Not only do they have a lot to cope with, they also have to consider whether they're to blame for their problems. Did my stress cause my cancer? And is it preventing me from getting well? Would I have gotten pregnant if I hadn't been in some way receptive to the rape?
Another problem is that all this emphasis on stress causes us to assume that it is a modern phenomenon, that humans are more stressed today than ever. This simply isn't true.
We are certainly stressed in different ways than in previous eras. But for most of human history, stress was even more stressful, sometimes involving having to sprint for your life. Today, our stressors are more likely to be chronic psychosocial ones — money worries, say, or feeling overwhelmed at work. These are utterly different stressors than in earlier eras. No matter how poorly a meeting goes with our boss, our bones aren't going to wind up scattered across the savanna. We also have lousy social support for our stressors. For perhaps the first time in history, many humans live thousands of miles away from their families, surrounded by neighbors whose names they don't know. It's not that we have more stress these days. What we have is the luxury of living long enough to pay the price for the stress we do have.
It's a great thing that people have learned that lifestyle choices and stress can affect health. They can. But it's a real problem when the importance of stress is oversold. As we saw last week, misunderstanding the role of stress can fuel a politician's toxic ideology. And even worse, it means that a medical insight with the potential to improve lives becomes instead a route for blaming victims.
Robert M. Sapolsky is a professor of neuroscience at Stanford University and the author of "A Primate's Memoir," among other books. He is a contributing writer to Opinion.