Do you remember in high school when we had our groups or cliques as some would say? If you were popular you were probably loved by everyone, and if you were not, you were kind of an outcast. There were also all the other groups in the middle. I found a very interesting article that talks about female rhesus macaques, monkeys. They go through the same thing that most of us went through in high school. They form groups and the monkeys at the top socialize a lot. The monkeys who are ranked lower on the scale of popularity quarrel, and get ridiculed by peers.
Catherine Caruso from Scientific American talks about a study published by The American Association for the Advancement of Science published, on how the social status within these monkeys can affect their immune systems. She discusses how researches from Duke University, Emory University, and University of Montreal had 45 female macaques and divided them into 9 groups of social hierarchy. They then analyzed the macaques’ immune functions. The monkeys of higher status had an increase of immune cells to protect them from viral attacks, the monkeys with a lower status had intense activity and that responded directly to the bacterial invaders. They then formulated a hypothesis:
Hypothesis: The relationship between the social ladders to the monkey’s immune system is causal. Also, in varying social conditions, reverse causation is possible.
x-variable- rank of social status
y-variable- immune system (overall health)
confounding variable- no confounding variable, because this article was published and peer reviewed.
chance- could be a possibility
Reverse causation is possible because if you had a monkey who was quite sick (with a lower immune system), then that monkey wouldn’t be at the top level because the other monkeys wouldn’t want to be around the sick monkey.
The researchers then manipulated these groups and make up their own ranks. The higher class had many social bonds while the lower class were still being harassed and out casted. What is the mechanism? Why does this keep happening? Caruso begins to ask questions like, do they start out already sick? The lower class monkeys don’t get good access to good food while the other higher class monkeys find better food.
Jenny Tung (co-author) and her colleagues at Duke wanted to test whether social status really was the x-variable. The researchers put all the high class monkeys together and grouped them going down the social hierarchy. Again we have 45 monkeys being put into 9 groups of 5. In the highest group of monkeys, the lower class one out of that 5 had a lowered immune system. This shows a very strong causal relationship between social class and immune system in the rhesus macaques.
Another article titled “How Social Status Affects Your Health”, by Christopher von Rueden from the New York Times talked about the same concept but on humans. Rueden and his colleagues did a study for a couple of years on people Tsimane horticulturalists in Bolivia. They concluded a study and found that men with a lesser amount of political influence had increased levels of cortisol, a stress hormone. In this study they did control other factors like body and age. Like the last article, the main thing we are looking for is the mechanism. Rueden talks about how maybe the people in the higher class have access to people in the food production area so they remain well-nourished and healthy. Maybe the lower class does not get that much support and that is why they are so stressed. There could be many reasons to the why, but again we don’t know the exact reason.
I was really interested in some of the other reasons for this causation. From an article titles, “Work, Stress, and Health, and Socioeconomic Status”, from the American Psychological Association, there are many possibilities that could be the mechanism. Of course this depends on the place and subjects you are studying, but again these are just hypotheses. One reason was that people whose work requires a heavy work load might require a lot of physical demand. This could easily take a whole on one’s health. Also if one is stressed from a lot of work, this could lead to fatigue and sleep deprivation. Overall most of these reasons had to do with stress taking toll on one’s health emotionally and physically.
This was definitely a really interesting article. From monkeys to humans, the causation is most definite. I definitely think more studies would be interesting to look into. I am not going to lie, this does kind of scare me. Just by the way one is socially ranked takes a toll on one’s health. Is it just a psychological thing? Can one beat it?
Ahh so interesting
(2016) Work, Stress, and Health and Socioeconomic Status. American Psychological Association.
Carcuso, C. (2016) Who’s Top Monkey? How Social Status Affects Immune Health. Scientific American.
Rueden, C. (2014) How Social Status Affects Your Health. The New York Times.