WHAT is the relationship between social status and health?
It’s a tricky question. In modern industrialized societies, health certainly improves as you move up the socio-economic ladder, but much of this trend is the result of health care and lifestyle factors (diet, physical activity) that are associated with income – not relative social position per se.
If you want to see how status affects health, you need to isolate status from material wealth. How to do that? The easiest way is to observe a society in which there is a modicum of material wealth to contest and where opportunities for status competition are limited.
So that’s what my colleagues and I did. For several years, we have studied the Tsimane forager-horticulturists of Amazonian Bolivia, a small, pre-industrial, politically egalitarian society in which status confers no formal privileges (such as coercive authority). As we report in a recent article in the journal Evolution, Medicine, and Public Healthwe found that even among the Tsimane, higher status was associated with lower stress levels and better health.
Along the banks of the Maniqui River and in the adjacent forests, the Tsimane hunt, fish and plant plantains, rice and sweet cassava. They live in villages ranging in size from 30 to 700 people. At village meetings, decision-making is based on consensus. No individual has the right to coerce anyone else.
But that doesn’t mean there aren’t any status distinctions. When you attend a Tsimane village meeting, you quickly notice that some men’s opinions are more influential in the consensus-building process. These same men are often asked to arbitrate conflicts or to represent the interests of the villagers to foreigners. (Many Tsimane women have a voice in community affairs, but it is rare in such small-scale societies that women, on average, have equal status with men.)
My colleagues and I measured the social status of all men in four Tsiman villages (nearly 200 men aged 18–83), asking them to rate each other on their informal political influence. The men also provided urine samples and underwent medical examinations by doctors associated with the Tsimane Health and Life History Project.
We found that Tsimane men with less political influence had higher levels of the stress hormone cortisol, which has many important physiological functions. This result persisted after controlling for other factors that may affect stress levels, including age, height and personality.
Additionally, we found that less influential Tsimane men had a higher risk of respiratory infection, the most common cause of illness and death in their society. Stress may contribute to this disparity in infection risk; when chronic, stress can weaken immune function.
By studying the same individuals over a four-year period, we also found that for men whose influence diminished over time, greater declines were correlated with higher levels of cortisol and respiratory disease. Downward mobility is harmful, it seems, even in an egalitarian society.
Why can lower status cause such stress for the Tsimane? One possibility is that status provides a greater sense of control. Another is that status acts as a form of social insurance. Influential Tsimane men have more allies and food production partners, who can be helpful in mitigating conflict, disease, and food scarcity. The relative lack of such support can cause psychosocial stress.
Our study is limited to adults, but further studies could examine whether childhood and adolescence are important periods in Tsimane society for establishing the social bonds that engender status and regulate stress. Recent studies in industrialized societies have shown that adults who experience low socioeconomic status in childhood exhibit heightened responses to cortisol in adulthood, regardless of their current socioeconomic status.
Interestingly, even in industrialized societies, the most important status comparisons for psychosocial stress are often between individuals who live in close proximity to each other or occupy the same social network, not individuals at opposite ends of the spectrum. socio-economic spectrum. Those living just above the poverty line may feel welfare for those living just below, and a millionaire may envy a multi-millionaire more than they envy a billionaire.
The importance of perceptions of relative status may have its roots in the small-scale societies of our ancestors, which were similar to that of the Tsimane. In such societies, our political competitors and cooperative partners were probably individuals with whom we interacted regularly.
As our society debates the effects of wealth inequality, the Tsimane help us understand why we care so deeply about relative social position – and why our health depends on it.