Michael Marmot's book, The Status Syndrome, is about how a person's social rank influences his or her health. The book's focus is on conditions in the richer countries, as opposed to those nations so poor that one would expect poor health. Social rank may be measured in a number of different ways, such as education, or income. Marmot, a British health researcher trained as a medical doctor, did much of his research on the British civil service, which ranks its employees with some precision. He emphasizes that rank does not act like a binary variable, leaving the poorest in poor health and everyone else in reasonably good health, but rather in a continuous fashion, with those of middling rank having health outcomes midway between those of the lowest and highest social ranks.
The great difficulty with social science research such as this is to disentangle confounding hypotheses in circumstances where an experiment is impossible. Here, besides the hypothesis that social rank has direct effects on health, there are at least two other major alternative hypotheses, first that its a sickly nature that reduces ones social rank, and second that those at the top of the pyramid are just generally more able people than those lower down. Studies of social mobility indicate a direct effect of one's current circumstances on health. Furthermore, experimental studies with non-human primates also show that the animal's place in the social hierarchy effects health in the same way observed in human populations. What an ecologist would call a natural experiment, the fall of communism in eastern Europe and the economic disruption that subsequently occurred, also provides evidence that a person's place in the social hierarchy affects his or her health. The proximal benefits of a higher social rank seem to be not just more money, but also more control over you life. Both of these reduce chronic stress, which appears to be the cause of the health problems of those lower down. Being busy or having a responsible job does not cause stress if you can control your own working conditions.
Marmot believes that humans have an innate dispoisition to form social hierarchies, based on his understanding of what is called evolutionary psychology. Or at least human males do; women may be somewhat inadvertantly caught up in the process. Womens' health responds to their social position similarly to men. The more cooperative nature of women may bring men to act more cooperatively, as mens' tendency to create hierarchy may cause women to act hirarchically. I cannot claim to know enough population genetics to comment on the validity of these ideas, which are however similar to those I was exposed to in a graduate ecology program which had a number of persons interested in animal behavior on its faculty.
Marmot believes that the effects of social hierachy can be ameliorated if not eliminated, through government policies to improve education among the disadvantaged and redistribute wealth. He was part of a committee which made recommendations along these lines to the Blair government in the 1990s. To me, these ideas (the recommendations are listed in an appendix to the book) seem utopian in an American context.
I published a similar review at goodreads.com