I have an essay in the NYT Sunday Review on socioeconomic class, stress, and health. The gist: the lower one ranks in society, the more stressed, and the worse one’s health. Many see the yawning divide between the haves and have-nots as a public health issue, and even as an economic problem. (How better to save money on healthcare costs than to prevent disease in the first place?)
Nothing about microbes in this one, although there’s plenty about developmental biology. One thread of the argument: Excess stress while young may rewire your nervous system in a way that predisposes to diabetes, heart disease and other problems.
As usual, lots of interesting stuff didn’t make cut, including some nuances and caveats. See below.
IS LIFE AT THE TOP REALLY EASY?
So, first things first. About the CEOs. According to this 2012 study of American military personnel and government officials, stress levels as measured by cortisol levels do correlate with rank.
Leadership benefits those who lead because, the authors argue, they have that all-important sense of control over their lives.
Now, for the exceptions to this rule. The benefits (or costs) you may accrue from being the top dog could dependent in part on what you’re top dog of. CEOs of banks going through bankruptcy may actually have quite high cortisol levels, as the renown neurobiologist Robert Sapolsky points out in a nice commentary on the study.
This overstressed CEO idea is supported by studies on monkeys. When the hierarchy is unstable (scientists destabilize it by introducing foreign males willy-nilly, stressing out the dominant male) the alpha male ends up more stressed than anyone else.
(Here’s a review of this work on male monkeys.)
But when the hierarchy stabilizes, and the animals return to happily abusing those that rank just below them, it’s the lowest ranking males (and females) who suffer most.
Now, even that caveat has its own caveats, it turns out. Different macaque species behave differently. In some, where order is maintained with constant physical aggression (versus more subtle means—intimidation without aggression), then the top guy, who’s always smacking everyone else around—and always on edge because he’s worried about being overthrown by some upstart—is quite stressed. In wild savanna baboons, these scientists found that the very top animal was actually the most stressed, and those immediately below him least stressed, with stress again increasing toward the bottom.
As Robert Sapolsky again points out, one way to coin a rule from these seemingly divergent results is to recognize that whether being on top means stress or improved health depends on what being at the top means. Yes, it seems like circular reasoning, but it also helps us drill down on what really matters. For monkeys, stress levels experienced by those at the top depends in part on the species, the individuals in question—monkeys have personalities and personal histories—and the greater culture of the troop.
For people, it’s even more complicated. In that first study on military and government personnel, the middle-manager types were actually the most stressed. That’s because, the authors argue, they have lots of responsibility, very little control, AND higher-ups breathing down their necks.
But even that is not an easily made generalization. As Sapolsky again points out, we tend to belong to multiple hierarchies—not just our job, but reading clubs, sports teams, church, synagogues, extended family (that hopefully doesn’t stress you out). We tend to value those hierarchies that rank us highest. Which means that we can, if we have access and wherewithal, belong to one hierarchy that buffers the effect of ranking low in another.
In other words your basketball Wednesdays or prayer group Sundays could counteract the negative health effects of having a really crappy boss at your low-ranking position at the local McD’s.
AFFLUENCE AND STRESS
Are middle class and well-to-do people never stressed? Absolutely not. Plenty of wealthy people are. And plenty will have been overly stressed as children. Likewise, plenty of poor people overcome their humble beginnings and rise.
(For a more nuanced exploration of these relationships with much more on-the-street reporting than what’s in my NYT essay, see Paul Tough’s excellent How Children Succeed. )
But to give an idea of the relative distribution of early life adversity in the population, consider that, according to the government, poor children are 3 times as likely to be abused and 7 times as likely to be neglected compared to their better off counterparts.
It’s also important to remember that health improves all the way across the socioeconomic gradient. The poor may be three times as likely to die before age 65 compared to the rich, but the middle income brackets are twice as likely to expire prematurely. No one escapes the Status Syndrome.
Now here’s some research showing how people overcome low SES. In this study, scientists observe that maternal warmth can uncouple early-life SES and the elevated markers of inflammation researchers find in adulthood. You get enough love and support form mommy, in other words, and the other stresses seem not to have that negative long-lasting effect.
In general, social support protects against these effects. Which brings me to a very interesting phenomenon: the Hispanic paradox. Many Hispanic (and non-hispanic) immigrants rank quite low socioeconomically in the US. But over and over, they’re found to be healthier than native-born Americans, including their own US-born children. This is remarkable and no one can quite figure out why. But the phenomenon may relate to the fact that immigrants often have their own social networks and very strong social support. They also may live in enclaves, which appears to improve health. By living somewhat insulated, they may escape the negative consequences of lowly rank in the larger society. We could all learn something from this phenomenon.
WHY DOES STATUS AFFECT OUR BIOLOGY DIRECTLY?
The changes seen in primates (including us) according to status may be adaptive in the proper context. That is, if you’re facing a real threat, adrenalin, increased heart rate and blood pressure are all good ideas. And even some of the differences seen in children of low SES may not mean that they’re ruined in any sense, but that they’re actually better adapted to a certain environment (usually not the one the researchers belong to).
Here’s an example: Peter Gianaros carried out a study wherein he found that college students reacted more strongly to pictures of angry faces according to their parents’ standing. The lower they ranked, the greater the fear response as judged by amygdala (brain area) activity.
But if you’re ranked low, it may pay to react more strongly. Fear is adaptive when there’s something worth being afraid of. If you live in a more chaotic environment, for example, where more scary things are occurring, maybe it’s good to resopnd quickly and dramatically to threatening stimuli. It’s a matter of survival at some level.
The argument is a little speculative, but consider this: In another study, scientists at UCLA found that areas of the brain associated with “mentalizing”—imagining another person’s internal life—lit up more the lower the student ranked him or herself at school. The authors postulated that if you rank low, you’re sort of compelled to imagine what others are thinking. To some degree, your wellbeing and survival depend on accurately gauging what those in power are thinking. IN this study, they observed increased activity in an area of the prefrontal cortex AS WELL AS the amygdala, which is what Peter Gianaros observed.
So it’s all complicated, especially when we begin to look at other behavioral tendencies.
These UCSF scientists have done interesting work on chronic stress and craving for “comfort food”—fat, sugar and grease. Basically, the more stressed an animal is, the more it eats fatty, energy-dense food, and the fatter it gets. It’s almost like they’re self-medicating. And in fact, in some sense, they are. The visceral fat somehow blunts their stress hormones.
The scientists observe parallel phenomena in humans–a relationship between stress, abdominal fat, and food craving. In this study by a different group, chronic stress was associated with more food craving, and greater consumption of chocolate cake(!).
Again, there’s a strong argument that these behavioral changes are adaptive in some sense. If we just imagine ourselves as the social apes we are, it’s a little easier to see: you’re a primate and under great psychosocial stress, so your calculus for how to expend and store energy changes. If you have access calorie-dense food, you should gorge quickly before it’s gone. Your world is an uncertain place. Who knows when food will be available again. And you should store your excess energy as fat, not burn it off. Again, these behavioral and metabolic adjustments are perfectly suited to an environment of great uncertainty and stress. That’s exactly what you should do.
Finally, there’s interesting work on how stress changes habitual behavior. Scientists at USC recently found that when stressed, people tend to fall back on established habits—as if, when stressed, you just don’t have the energy to NOT do what’s already ingrained. This could be both good or bad, depending on the habit in question. The takeaway is that when the going gets tough, you PFC (executive control) goes offline somewhat; you rely on other parts of your brain; and you do what you’ve previously learned to do.
I feel like the military, police, paramedics, firemen all know this already. That’s the point of repetitive training exercises—of drills ad nauseam. When you’re facing the real deal and your adrenalin is pumping, you don’t have to think. You fall back on your training (habits). These scientists are essentially saying we do this all the time anyway.
THE USUAL SUSPECTS — DIET, EXERCISE, SMOKING, DRINKING, ETC.
The better-known suspects—smoking, lousy diet, lack of exercise—do tend to correlate with status. In the more recent studies on British civil servants, it’s pretty clear that unhealthy habits tend to increase inversely with rank. The lower you rank, the more likely you are to smoke, not exercise, eat fatty, sugary foods, and NOT eat fruits and veggies.
When the scientists control for these risk factors, they end up accounting for over half of the difference between ranks. You could argue that’s high, and reason enough to forge ahead with campaigns urging people to quit smoking, exercise more and eat better. I agree. But you could also say, only half? What’s the other half we can’t figure out? (At least in the case of diabetes, scientists studying the same cohort impugn that darn inflammation that correlates inversely with rank, and which animal studies suggest can result directly from chronic stress).
Here’s what’s interesting about Michael Marmot’s response / argument to this conundrum. He makes the point in his book and elsewhere that where you rank changes your behaviors by, at least in part, altering your day-to-day cost-benefit analyses. You may know that smoking is bad for you, but since you feel helpless in other aspects of your life, you smoke anyway–just to have that moment of relaxation and pleasure.
Stress, in other words, can shift your calculus toward choosing short-term payoffs over long-term ones. It’s very difficult to disentangle so-called modifiable risk factors—diet, smoking, exercise—from the stress of your rank. The latter influences the former.
So, status has a huge role in how the modifiable risk factors play out, which makes you wonder if they’re really modifiable. Are people really making bad choices out of ignorance, or because stress compels you somehow toward unhealthy behaviors?
(These arguments leave aside inequalities in access to healthful resources—to places to exercise, money for gym memberships, access to more pricey fresh fruits and veggies, beaches, and especially supportive social networks.)
The implication of Marmot’s argument is, solve the problem of great inequality — address that feeling of lack of control over one’s life — and the secondary problems may self-correct.