I've got a new article in the latest Wired on the science of stress, as seen through the prism of Robert Sapolsky. The article isn't online yet (read it on the iPad!), but here are the opening paragraphs:

Baboons are nasty, brutish and short. They have a long muzzle and sharp fangs designed to inflict deadly injury. Their bodies are covered in thick, olive-colored fur, except on their buttocks, which are hairless. The species is defined by its social habits: The primates live in troops, or small groupings of several dozen individuals. These troops have a strict hierarchy, and each animal is assigned a specific ranking. While female rank is hereditary--a daughter inherits her mother's status--males compete for dominance. These fights can be bloody, but the stakes are immense: A higher rank means more sex. The losers, in contrast, face a bleak array of options: submission, exile, or death.

In 1978, Robert Sapolsky was a recent college graduate with a biology degree and ajobinKenya.Hehadsetoffforayearof fieldwork by himself among baboons before he returned to the US for grad school and the drudgery of the lab. At the time, Sapol- sky's wilderness experience consisted of short backpacking trips in the Catskill Moun- tains; he had lit a campfire exactly once. Most of what he knew about African wildlife he'd learned from stuffed specimens at the Museum of Natural History. And yet here he was in Nairobi, speaking the wrong kind of Swahili and getting ripped off by everyone he met. Eventually he made his way to the bush, a sprawling savanna filled with zebras and wildebeests and marauding elephants. "I couldn't believe my eyes," Sapolsky remem- bers. "There was an animal behind every tree. I was inside the diorama."

Sapolsky slowly introduced himself to a troop of baboons, letting them adjust to his presence. After a few weeks, he began recog- nizing individual animals, giving them nick- names from the Old Testament. It was a way of rebelling against his childhood Hebrew school teachers, who rejected the blasphemy of Darwinian evolution. "I couldn't wait for the day that I could record in my notebook that Nebuchanezzar and Naomi were off screwing in the bushes," Sapolsky wrote in A Primate's Memoir. "It felt like a pleas- ing revenge."

Before long, Sapolsky's romantic vision of fieldwork collided with the dismal reality of living in the African bush. His feet itched from a fungal infection, his skin was cov- ered in bug bites, the Masai stole his stuff, he had terrible diarrhea, and he was des- perately lonely. Sapolsky's subjects gave him no glimpse of good fellowship. They seemed to devote all of their leisure time--and baboon life is mostly leisure time--to mischief and malevolence. "One of the first things I discovered was that I didn't like baboons very much," he says. "They're quite awful to one another, constantly scheming and backstabbing. They're like chimps but without the self-control."

While Sapolsky was disturbed by the behavior of the baboons--this was nature, red in tooth and claw--he realized that their cruelty presented an opportunity to investi- gate the biological effects of social upheaval. He began to notice, for instance, that the males at the bottom of the hierarchy were thinner and more skittish."They just didn't look very healthy," Sapolsky says. "That's when I began thinking about how damn stressful it must be to have no status. You never know when you're going to get beat up. You never get laid. You have to work a lot harder for food."

And so Sapolsky set out to test the hypothesis that the stress involved in being at the bottom of the baboon hierarchy led to health problems. At the time, stress was mostly ignored as a scientific subject. It was seen as an unpleasant mental state with few long- term consequences. "A couple of studies had linked stress to ulcers, but that was about it," he says. "It struck most doctors as extremely unlikely that your feelings could affect your health. Viruses, sure. Carcinogens, absolutely. But stress? No way." Sapolsky, how- ever, was determined to get some data. He wasn't yet thinking lofty thoughts about human beings or public health. His transformation into one of the leading researchers on the sci- ence of stress would come later. Instead, he was busy learning how to shoot baboons with anesthetic darts and then, while they were plunged into sleep, quickly measure the levels of stress hormones in their blood.

In the decades since, Sapolsky's speculation has become scientific fact. Chronic stress, it turns out, is an extremely dangerous condition. And it's not just baboons: People are just as vulnerable to its effects as those low-ranking male apes. While stress doesn't cause any single disease--ironically, the causal link between stress and ulcers has been largely disproved--it makes most diseases significantly worse. The list of ailments connected to stress is staggeringly diverse and includes everything from the common cold and lower-back pain to Alzheimer's disease, major depressive disorder, and heart attack. Stress hollows out our bones and atrophies our muscles. It triggers adult onset diabetes and is a leading cause of male impotence. In fact, numerous studies of human longevity in developed coun- tries have found that "psychosocial" factors such as stress are the single most important variable in determining the length of a life. It's not that genes and risk factors like smoking don't matter. It's that our levels of stress matter more.

Furthermore, the effects of chronic stress directly counteract improvements in medical care and public health. Antibiotics, for instance, are far less effective when our immune system is suppressed by stress; that fancy heart surgery will work only if the patient can learn to shed stress. As Sapolsky notes, "You can give a guy a drug-coated stent, but if you don't fix the stress problem, it won't really matter. For so many conditions, stress is the major long-term risk factor. Everything else is a short-term fix."

The emergence of stress as a major risk factor is largely a testament to scientific progress: The deadliest diseases of the 21st century are those in which damage accumulates steadily over time. (Sapolsky refers to this as the "luxury of slowly falling apart.") Unfortunately, this is precisely the sort of damage that's exacerbated by emotional stress. While modern medicine has made astonishing progress in treating the fleshy machine of the body, it is only beginning to grapple with those misfortunes of the mind that undo our treatments.

The power of this new view of stress--that our physical health is strongly linked to our emotional state--is that it connects a wide range of scientific observations, from the sociological to the molecular. On one hand, stress can be described as a cultural condition, a byproduct of a society that leaves some people in a permanent state of stress. But that feeling can also be measured in the blood and urine, quantified in terms of glucocorticoids and norepinephrine and adrenal hormones. And now we can see, with scary precision, the devastating cascade unleashed by these chemicals. The end result is that stress is finally being recognized as a critical risk factor, predicting an ever larger percentage of health outcomes.

There's a lot more in the article. Here's one example of how stress destroys the body. Elissa Epel, a former grad student of Sapolsky's and a professor of psychiatry at UCSF, has demonstrated that mothers caring for chronically ill report much higher levels of stress. That's not surprising. What is surprising is that these women also have dramatically shortened telomeres, those caps on the end of chromosomes that keep our DNA from disintegrating. (Women with the highest levels of stress had telomere shortening equal "to at least one decade of additional aging.") When our telomeres run out, our cells stop dividing; we've run out of life. Stress makes us run out of life faster.


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Pleased to see you're writing up Sapolsky; he's fascinating, barrels of fun, and endlessly thoughtful. This should be a nice match of writer and subject.

I hope to read this thing tonight on my iPad. I'm curious to see, among other things, if you look at the question of how to draw the line between constructive, healthful challenge, which is good for body, brain, and psyche, and stress, which in a sense is simply a challenge you're not quite up for, whether acutely or as an ongoing thing. One man's healthful challenge might be another's harmful stress, in a sense -- and what's a healthy challenge for me one day may be a bit much for me on another in which I'm simply already overtaxed, underfed, etc.

It's a slippery issue, but an important one. And while Sapolsky and other stress researchers such as McEwen have shown well how stress can erode health, I think sometimes as a culture we begin to miss the fact that even very demanding challenges can create health -- and indeed bring out the very best in us and can create immense health and happiness. It's not QUITE as simply as "What don't kill you makes you stronger." Yet there's something to that -- a something that often gets lost. I look forward to seeing if and how that comes up in the story. If you didn't have room for it there, love to see here what you found. I would love to see, for instance, a telomere study of a sort of spectrum of challenge/stress exposure, so that we might see at what point (and by what other variables) healthful challenge becomes stress. Perhaps you came across such?



Thanks for such a thoughtful comment, David. I spend a chunk of the piece investigating why many activities that slightly raise levels of stress hormone (exercise, sex, enriched environments) are actually good for us over the long term. Elizabeth Gould is currently doing some very cool work searching for the additional molecules that might buffer or counteract the hazardous elements of the stress response. Her initial search focuses on the molecules of pleasure (dopamine, oxytocin), which suggests that when stress is paired with pleasure the stress isn't destructive, but can actually be good. That said, the research at this point is mostly a search, so it's all very inconclusive.

That's why we need your book!

I agree with the previous poster. Perhaps it's not stress but failure to adapt to it that is deadly - the principle of hormesis. Having a tyranical boss or being unemployed would be the most difficult stress for successful adaptation and therefore the most destructive.

Jonah: I just want you to know I'm reading your book "How we decide" I love it so far. I'm contemplating switching to a psychology're an inspiration. Please don't think I'm a sappy fan or a lame teenage girl...I mean it. You are wonderful.

I suppose the disctinction between "good" and "bad" kinds of stress can be expressed as eustress and distress, respectively - but these terms seem to be out of use. I mention them because it is an old idea that pressure from circumstances and anxiety can be found in both favorable situations (e.g., sex, sports) and their opposite (e.g., self-defense). The body reacts similarly to both (adreno-cortical responses). The difference? In the brain, of course.

Is there any research out there about what happens to your long-term health outcomes after you start dealing with stress? If you start to get a handle on your stress and find a way to manage it, does the level of risk for certain long-term health outcomes improve (in the same way that it's never too late to quit smoking)?

There exists prior stress research, circa 1950's, that comes to mind. "The Stress of Life," and "Stress Without Distress," by Hans Selye, deal with the effects of stress on mind and body. Dr. Selye pointed out connections between stress and both auto-immune system and mental problems. "Stress Without Distress" opens with a quote from Montaigne that echoes Seneca: "No wind favors him who has no destined port."

By OftenWrongTed (not verified) on 20 Jul 2010 #permalink

I think I have read nearly everything Robert Sapolsky has written for the public and I am so glad he is on your radar and you are writing about his work.

One thing I have not seen much in his writing and I am wondering if you have any comments on; what are the effects on an unborn fetus of a chronically stressed mother?

"One man's healthful challenge might be another's harmful stress, in a sense."

"Perhaps it's not stress but failure to adapt to it that is deadly"

Commenters don't appear to be thinking through these issues very thoroughly. From the article: "The primates live in troops, or small groupings of several dozen individuals. These troops have a strict hierarchy, and each animal is assigned a specific ranking."
Now this appears to indicate that there is no possible way for certain low-ranking animals to "adapt" to their stressful position in life. Put simply, in any ranking arrangement there will be a top and a bottom rung, no amount of adaptation can change this. The lower-ranked animals are not facing a "challenge" that can simply be overcome with different actions or traits. The ranking are zero-sum, some baboons must be at the bottom of the ranking no matter their genes or dispositions.

This conclusion, that the type of stress experienced by low ranking baboons is a zero-sum game, is reinforced by the Whitehall Studies of British civil servants. Low-ranking workers experience detrimental health effects regardless of their stress level away from work. This was found among a group in which every member is ostensibly "highly-ranked" as compared to society at large. That is to say, these people all had well-paying, well regarded and stable careers. From this it seems certain that the problems associated with low status cannot be explained by genetic predispositions or failure to overcome "challenges".

In short, the extent to which hierarchy diminishes the health of those towards the bottom is not dependent on individual traits, but on societal (or species-wide) traits.

On a somewhat separate note: Why the heck would hierarchical species evolve in a way that leaves large portions of their population with an increased susceptibility to disease and premature death?

By uff the fluff (not verified) on 21 Jul 2010 #permalink

the comment by Uff is great. As a low-level clerk who exists to do what is beneath others, the lack of control over what i do is extremely stressful. For instance, being told to do something that i'm pretty sure is illegal, or i'll be fired. It's pretty stressful to compromise my ethics for a paycheck. How does one acclimate to that stress and still live paycheck to paycheck? (I know there's laws, but even so, they'll come get my house before I can get another job these days.) I love the question about "evolving" as a hierarchical species. This is the difference between an evolved human who believes he is his brother's keeper and another who believes it's every man for himself or survival of the fittest.

Thanks for this article; it really strikes close to home for me. I had an abusive childhood and I have a chronic stress response from it. I've been slowly trying to change, but it is extremely hard. And I have to admit, reading these sorts of things can be very depressing because I have to wonder how much is even possible to "change" - how much is hardwired into me now that is beyond my control?

The article has re-inspired me to really concentrate on ways to reduce my stress, such as meditation and walking/hiking in nature - the problem is how difficult it can be for me to instill new habits like this. The stress and depression leave me feeling exhausted most of the time, with no energy to pursue these things, which in turn keeps my stress up and around and around I go...

Maybe I'm simple. It seems pretty intuitive that stress and ill health, low status, starvation and such are connected. I'm not seeing any proof that one causes the other. Stress as the cause of ill health, and not vice versa seems the less likely alternative, but I see no proof of either.

There was a good cover article in Time some time last year about the effects of stress and other uterine environmental pressures (body fat % of mother etc). The take away is that a developing fetus takes cues from its mother about what kind of world its being born into. Everything they measured about the mom went into the fetus too.,8599,2020815,00.html

it has been thoroughly established that prolonged high levels of stress (cortisol) lower immune response and cause other measurable damage to the body.

Robert Sapolsky is awesome!

Hi there,

I agree with the above comment...Sapolsky's work is excellent. I show his National Geographic documentary Stress: Portrait of a Killer to my undergraduate psychology class when we cover Stress & Health. He does an excellent job at showing the origin of stress from a biological and evolutionary perspective. His book, "Why Zebras Dont Get Ulcers" is also a great resource and available as a podcast on itunes as well.

Natascha S.

Stress comes in a great many forms and some people are more vulnerable than others for any one of thousands or millions of reasons unique to the individual. It would be nice if we were all able to view life as a constant stream of challenges, rather than a constant source of stressors.