Even in the world of monkeys, the lowest social ladder is shorter and sicker

Mohammed Shaban

A recent study of monkeys revealed that their communities are not much different from human societies where those at the bottom of the social ladder live a shorter life and a healthier life than those above. What is interesting about the study, however, is that the pressures associated with lower-class life have long-term health effects even if social promotion tries to modify them.

The longevity and the situation changed
The study, which was published October 14 in the journal "PANAS", was conducted by a team of researchers at Duke University and the University of Chicago on 45 female Macaques Risosi monkeys.

The scientists highlighted that difficult social experiments remain preserved and show their long-term health effects, according to the study. Although some monkeys have risen in the social pyramid, they have shown, at the cellular level, traces associated with their lower rank.

Females put macaques in groups, and the females tried to race among them to get a higher rank for each and then establish a social class in that group, so that the dominant female - and of course at the top of the social pyramid - everything you want, and the first to get Food, location, mating and ordering to show control, while the rest of the subordinate females must make way for them and wait for their roles.

Immune genes and marital status
At the beginning of the experiment, the researchers placed female monkeys, who had no connection between them and did not know each other, in groups of five. Monkeys were introduced into each group one by one. Thus the monkeys arranged themselves based on seniority. Whoever arrived first served first, and deserved to win the highest rank in that group.

So the newly arrived females have begun to show fear and decline rather than coexist on the ground. A year later, scientists changed all that. These groups were reconstituted so that the monkeys that were at the end of the former social ladder were selected and introduced as the first individuals in a new group that included new members that reflected their rank. Thus a new social order was established.

By changing the memberships of the members of the same group, the condition of the monkeys has also changed, so that the monkeys that were previously inferior rank became dominant, while others moved down the pyramid and became more capitulated.

The scientists then analyzed the blood of monkeys. In a previous study, published in 2016 by the same team, scientists found that the female rank in the group influences how thousands of genes are activated or inhibited in blood cells, especially those immune genes responsible for infection control. In low-ranking females, many of these genes have collapsed in such a way that their immune system is easily affected by any microbe.

The decline of the past affects the present
The results of the study showed that the current social class of monkeys is not the only thing affecting, as the history of its social rank also plays an important role.

Researchers have identified 3,735 genes that show that their activity is influenced by the hierarchy of monkeys in the past no matter what those monkeys are in the present.

"Females who have scored one or two degrees in the social ladder have also shown their effects on their genes," said Luis Barreiro, lead author of the study at the University of Chicago.

What is surprising, however, is that even if these females try to move up the social ladder, what they have experienced in the past still has implications for their immune genes today.

"Our findings suggest that the body remembers the low social status it has suffered in the past and then digs in memory much more powerfully than it was," said Jenny Tong, co-author of the study and professor of evolutionary biology and anthropology at Duke University. In the past, suggesting that embedded biological processes work even in adults. "