Social status affects the immune system
Two rhesus monkeys. Photo: Lauren Brent
Why do so many social animals tend to increase their influence and power to climb up the social ladder relatives? The answer is clear: according to the theory of natural selection in these individuals higher the chances to leave quality offspring. But there are interesting side effects. A study of female rhesus monkeys confirmed the theory that low social status impairs the immune system. One expert said that the results of this study will almost certainly apply to humans, as in other social primates, it works that way. Subjective feeling less and poorer friends / relatives is harmful to health.
Better health and longer duration of the richest people in comparison with the poorest - has long been an established fact. In the US, the difference is more than 10 years for women and 15 years for men. Traditionally it is attributed objectively the worst living conditions of the poor, addictions: tobacco smoking and alcohol consumption, unhealthy diet of "junk" food and lack of athletic training, poorer medical care, etc.
But now it can be assumed that poor health affects and subjective factors - their own perception of the surrounding reality. The same poor man with the same habits and other factors being equal would have been healthier and lived longer if the people around him were below him on the social ladder. These conclusions follow from the research "Social status alters immune regulation and response to infection in macaques", if we apply these findings to humans.
Previous studies of hierarchically organized groups of primates have shown a correlation between the social status of primates and changes in the cardiovascular system, the function of the hypothalamic-pituitary-adrenal axis, increasing inflammation. According to scientists, this clearly shows the reaction of the immune system to change the social status of the person and other social primates.
A group of researchers from the US and Canada, conducted a study of 45 female rhesus monkeys to test the theory of the influence of social status on the immune system. To do this, they organized a group of primates studied, in which the social status of individuals specially altered for two years. The first phase in the graph refers to the study of the period of formation of the group between January of 2013 and March 2014. The second phase relates to the period between March 2014 and March 2015.
The diagram shows the formation of the group during the first phase. Social hierarchy Emphasizing the position from 1 to 5. After the formation of the hierarchy in each group, researchers selected individuals of the same rank - and formed a new group of them (phase 2). Accordingly, the primates had to build a new hierarchy. Out of every five high-ranking individuals four lowered their social status, including one occupied the lowest position in the group. And vice versa - from the five low-ranking individuals have raised the social status of four, including one occupied the highest position in the group.
The graph B shows an example of how to establish a social hierarchy for the five new members of the female sex. It can be seen, the social status of females is set for a few months and remains stable on the whole subsequent period. The graph C shows how the order of appearance of a new member of the group a negative effect on his social status (what later appeared in the group member - the lower will be its status). The graph D - frequency of harassment, depending on the social status. The graph E - the same dependence of the frequency of grooming (minutes per hour) of their social status.
The study found that the lowering of social status directly leads to deterioration of the immune system - namely, to weaken the response to stimulation with lipopolysaccharide (LPS).
Changing the immune response to stimulation with lipopolysaccharide in rhesus monkeys with different social status in the group
In the rhesus monkey blood samples of different social status differences found in 1600 corresponding to a different expression of genes responsible for the immune system. In low-ranking primate immune system works more aggressively, causing inflammation and a negative impact on other body systems.
It is likely that this is due to a decrease in the pleasure of grooming and increased stress from sexual harassment relatives. It suppresses the very low status of fact (ie the idea of their own lack of rights). Thus the low-ranking primates live in a state of chronic stress, stress and damage to health is well known.
However, not all so simple. Other studies indicate that the maximum level of parasites on the body marked, not low-ranking primates, and in primates with higher status. It can be assumed that the highest stress and the most severe disturbances in the immune system characteristic of primates with the highest and lowest status, and the most healthful level of social status is somewhere between them in society.
Photo: Lauren Brent
Image source
Scientists believe that by the social hierarchy in human society it is impossible to get rid of, but you can at least reduce stratification in society. Perhaps the reduction in wealth among the richest people can improve the health of people with low status.
Scientific work published November 25, 2016 in the journal Science (doi: 10.1126 / science.aah3580).
Referenced Materials:
- http://science.sciencemag.org/content/354/6315/1041
- http://www.bbc.com/news/health-38092146
- https://www.ncbi.nlm.nih.gov/pubmed/27063997
- https://www.researchgate.net/publication/303694650_Primate_reinfection_with_gastrointestinal_parasites_Behavioural_and_physiological_predictors_of_parasite_acquisition
You gotta wonder if there aren't other factors still. I mean, all things being equal with his own health habits, are all things equal in his social and familial situations? Are the stress factors the same at work? Does he worry about more issues due to lack of money and social status, causing his health to be impacted due to the stress? Does he have the same thinking habits that might be more applicable in a man of higher station, or does he have perhaps a more negative trend in thinking either due to his station, or as a partial cause to it? Does the higher-status wife have more sex or less sex than the husband of lower status?
What things are equal? If we are ONLY measuring one or two things, and not other factors that may have an impact on a person's health and well-being, then all things cannot be possibly construed as equal.
But, other than that, it's a great point!
I'm wondering if there has ever been a study about mindset/attitude changes within the primates that are studied. I think instinct is very black and white - accepted/ non accepted, either/ or....and i get that we can compare humans to primates in this regard to stress and that it makes for good science, sometimes. But what about the human ability to adapt by changing their mindset about situations, or being able to manage emotion or purposefully tolerate distress to decrease suffering.