Monday, April 4, 2016

Baboons and Culture Change

In my last post I summarized the differences between chimpanzees and bonobos as “chimpanzees are hierarchical, patriarchal, competitive, and violent, whereas bonobos tend to be more egalitarian, matriarchal, cooperative, and much less violent. “  It’s a generality, but there’s a bunch of truth in it.  Unfortunately most other primate groups (except for humans) seem to be more like the chimps than the bonobos.  (I think that human beings have the potential to be like either--or both.)

We often see biology as a certain kind of destiny.  While humans have the freedom to change, it sometimes seems like we are fighting our biology.  And most animals (unless trained by humans) seem to be locked into a social/behavioral styles.

However, one study of baboons found something interesting.  Baboons, as I said, tend toward a patriarchal, hierarchal culture.  The scientists in this study were observing a troop (their term) of baboons that were near a tourist lodge and foraged in their garbage dump.  More importantly, it was only the most aggressive males that were able to forage in this dump and when some meat in the dump was infected with tuberculosis, it was all the most aggressive males in the troop  that died.

This totally changed the culture of the group.  There were now more females than males and the males that were left were less aggressive toward less dominant males (although apparently not toward their peers) and toward females.  

For some reason, the researchers lost interest in this troop that they were studying, and they began studying another baboon troop--although they kept informal tabs on the first troop (which they called the Forest troop).  The deaths of the dominant males happened between 1982 and 1986.  Observations of the group stopped around 1986.  In 1993, the researchers began studying the Forest troop again and were surprised to find out that the less aggressive culture persisted.  This was surprising to them because male baboons, as they age, leave the troop they were with and bond with females in another troop.  By 1993 there were no adult males that had been with the troop in 1986, yet the behavior change that happened with the death of the aggressive males persisted.

As the researchers put it: “A decade after the deaths of the more aggressive males in the troop, Forest Troop preserved a distinct social milieu accompanied by distinct physiological correlates. Critically, as noted, no adult males …  had been troop members at the end of the tuberculosis outbreak. Instead, these males had subsequently transferred in as adolescents, adopting the local social style. A number of investigators have emphasized how a tolerant and gregarious social setting facilitates social transmission…”  The more tolerant and less aggressive culture persisted as incoming males adopted or were socialized to the new culture.

In some ways it’s as if the baboons shifted from a ‘chimp-like’ way of relating to a ‘bonobo-like’ way of relating and that difference persisted through a complete shift in the male members of the troop.  I wonder what that says about ways we can change human society--short of poisoning all the aggressive males.

Quote of the Day:  “In summary, we have observed circumstances that produced a distinctive set of behaviors and physiological correlates in a troop of wild baboons. Moreover, these behaviors were taken on by new troop members...
“Finally, these findings raise the issue of their applicability to understanding human social behavior and its transmission. Human history is filled with examples of the selective loss of demographic subsets of societies... The present data suggest that demographic skews may have long-term, even multigenerational consequences, including significant changes in the quality of life in a social group.” - Robert Sapolsky and Lisa Share


Optimistic Existentialist said...

I have always found baboons, and primates in general, to be so very interesting! I enjoyed this post :)

MoonRaven said...

Thank you!