Stacy Rosenbaum is a professor from the department of Anthropology, at the University of Michigan. A little while ago I attended a talk she presented on the relationship between early adversity and adult glucocorticoids in wild baboons. In more basic terms, she was studying how the levels of stress hormones in adult baboons are impacted by stressful experiences they had as juveniles. In one study this included experiences such as:
- Being born into a large group, increasing competition for resources
- Losing their mother before the age of four
- Experiencing drought in the first year of life
- Having a sibling born less than and year and a half after them, increasing competition for maternal attention
- Being born to a low ranking mother
- Being born to a mother who was socially isolated
Baboons who experienced three or more of these adversities tended to live an average of eleven years less! This would result in much less offspring, which isn’t ideal evolutionarily. Social skills were also affected by these experiences, as these harsh environments increases suspicion and mistrust of others. This would also increase stress, and thus also increase glucocorticoid levels.
This study collected over 9000 separate faecal samples to test them for cortisol levels, so that the results would not be affected by interacting with the baboons. They also only studied female baboons, as they stay in the tribe for life. This means they can see the affects their childhood has on their adulthood, unlike with males, who leave the tribe before reaching maturity.
(Source: William Warby)
Baboons with higher than average glucocorticoid levels have a 38% higher chance of dying, compared to baboons with lower than average glucocorticoid levels. This results in an average life shortening of about 4 years, which is a lot when their average life expectancy is 20.
This talk was particularly interesting, as studies have shown that these effects can be seen in humans, too. I myself have had my cortisol levels tested, to see if the steroids I was given as a premature baby had left any lasting effects. Thankfully they didn’t, but it was interesting to see the parallels between my own experiences and this talk.
The idea of going out into the wild and observing animal behaviour sounds amazing! It would be great to study things that can directly relate to helping both animals and people. Though academic work appeals a little less to me compared to things like animal handling and animal photography, it’s still something I want to consider.
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