My latest article for Wired is now online. It's about baboons, stress vaccines and the often dangerous effects of glucocorticoids. One of the subplots of the article is the severe health consequences of the social hierarchy, which I mostly discuss in the context of the Whitehall Studies:
For the past 25 years, Michael Marmot has been running the Whitehall study, an exhaustive longitudinal survey launched in 1967 that has tracked some 28,000 British men and women working in central London. What makes the Whitehall study so compelling is its uniformity. Every subject is a British civil servant, a cog in the vast governmental bureaucracy. They all have access to the same health care system, don’t have to worry about getting laid off, and spend most of their workdays shuffling papers.
The British civil service comes with one other feature that makes it ideal for studying the health effects of stress: It’s hierarchical, with a precise classification scheme for ranking employees (in other words, it’s the human equivalent of a baboon troop). At the bottom are messengers, porters, and security guards. Just above them are the clerical officers, followed by staff scientists and other professionals. This last group implements the policies dictated by powerful administrators who run the governmental agencies. Marmot wanted to investigate how differences in status “in people who are neither very poor nor very rich” might lead to measurable differences in health.
The differences are dramatic. After tracking thousands of civil servants for decades, Marmot was able to demonstrate that between the ages of 40 and 64, workers at the bottom of the hierarchy had a mortality rate four times higher than that of people at the top. Even after accounting for genetic risks and behaviors like smoking and binge drinking, civil servants at the bottom of the pecking order still had nearly double the mortality rate of those at the top.
What, then, determines our health? Why were people in the lower ranks of Whitehall dying at a younger age? Marmot was forced to conclude that the significant majority of health variation is caused by psychosocial factors, most notably stress. People of lower status in the Whitehall study experienced more negative stress, and this stress was deadly. (To take but one data point: Fully two-thirds of an individual’s risk of stroke was attributable to the person’s socioeconomic status.) In fact, we’re so sensitive to the effects of status that getting promoted from the lowest level in the British civil service reduced the probability of heart disease by up to 13 percentage points. Climbing the social ladder makes us live longer.
However, the Whitehall results aren’t a straightforward analysis of stress, at least not as it’s usually defined. After all, people in leadership positions often describe their jobs as extremely stressful. They work longer hours and have more responsibilities than those at the bottom of the bureaucratic hierarchy. Consider the self-report of Nigel, a high-status administrator: “There were 2,000 people, and I was responsible for all the personnel aspects, contracts, and all the common services … It had every sort of challenge that you could ever wish to meet. A very active job and a lot of stress, but a very enjoyable job, and you got a tremendous amount of satisfaction from doing a good job.”
Notice the reference to stress; undoubtedly Nigel thought of himself as a person under lots of pressure. In contrast, here’s the self-report of Marjorie, a lowly typist: “I went to the typing pool and sat there typing documents. Which was absolutely soul-destroying … The fact that we could eat sweets and smoke was absolute heaven, but we were not allowed to talk.”
The recurring theme in the self-reports of people like Marjorie isn’t the sheer amount of stress — it’s the total absence of control. Researchers call it the “demand-control” model of stress, in which the damage caused by chronic stress depends not just on the demands of the job but on the extent to which we can control our response to those demands. “The man or woman with all the emails, the city lawyer who works through the night has high demands,” Marmot writes. “But if he or she has a high degree of control over work, it is less stressful and will have less impact on health.” (This helps explain why the women with mean bosses and menial work showed the highest incidence of heart disease.) The Whitehall data backs up this model of workplace stress: While a relentlessly intense job like a senior executive position leads to a slightly increased risk of heart disease and death, a job with no control is significantly more dangerous.
The same effect applies even to the rich and famous. A few years ago, Donald Redelmeier, an epidemiologist at the University of Toronto, led a study of Academy Award-winning actors. His hypothesis was that having an Oscar gave people more control over their stressful careers. Instead of being forced to accept bad roles or work on mediocre movies just for the money, these stars could pick and choose their parts. This creative control, in turn, would lead to improved health outcomes. Redelmeier compared the award winners to two groups: (1) actors who had appeared in the same film as a nominated actor and didn’t get a nomination and (2) actors who had been nominated for an Academy Award but never won. The results were clear: People with Oscars lived, on average, four years longer than their less-successful peers, which represented a 28 percent reduction in death rate. As Redelmeier notes, this longevity boost is roughly equal to the effect that would come from “curing all cancers in all people for all time.”
