Most scientists work in labs. Robert Sapolsky worked in the Serengeti.
For nearly thirty summers starting in his twenties, he camped out in Kenya with the same troop of wild baboons. He named them. He knew their fights, their friendships, their breakdowns. He'd dart one, draw blood, get the stress hormones out of the sample, and look at what was making whose body fall apart from the inside.
He went there to study primates. He came back with a story about us.
what the baboons were doing
Baboons are a useful model for one specific reason: like humans, most of them don't have a daily fight for their life. They're not constantly chased by predators. They live in a stable social group. So the stress most of them experience isn't the running-from-a-lion kind. It's the politics.
And it turns out, baboons are obsessed with politics. They have a strict dominance hierarchy. Where you sit in it determines almost everything about your day: who you can intimidate, who can intimidate you, who you have to nervously give way to at the watering hole, who eats first.
Sapolsky started taking blood samples. He measured cortisol — the body's main stress hormone, the one that runs you down if it's chronically high. And he found something staggering.
Low-ranked baboons had elevated cortisol almost all the time. They lived in a low-grade state of vigilance — watch your back, don't make eye contact, get out of the way, take the worst food. Decades of that did real damage. Their bodies showed it: high blood pressure, suppressed immune systems, the kind of biological wear you see in humans heading toward heart disease.
Higher-ranked baboons? Lower cortisol. Better sleep. Better health.
It wasn't a lion eating them that was killing the low-ranked ones. It was the social position.
this is the part where it stops being about baboons
Sapolsky's quietly devastating point is that humans are the same animal.
You don't have to be running from a predator to be saturated in stress hormones. You can be a fully employed person, in no immediate danger, with a roof and a working microwave, and have a nervous system that's basically running like you're being chased — because of where you sit in the social hierarchies you actually exist in.
Hierarchies at work. Hierarchies in your friend group. Hierarchies in your own head about who you're supposed to be by now. Hierarchies inside an app that ranks you against people you've never met.
The cortisol doesn't care whether the threat is real. It just keeps coming.
the most dangerous predator most of us face is a feeling of permanently low rank in a hierarchy that doesn't even feed us.
why this isn't depressing
It would be easy to read all this and conclude we're all just doomed monkeys. Sapolsky's actual take is more useful.
First: the suffering is biological. It's not a character flaw. If your body is wired up after a year of feeling small in some hierarchy you're in, you're not weak. You're a primate experiencing exactly what primates experience.
Second: hierarchies are everywhere, but they're not all equally weighted. Some of the ones beating you up daily — Instagram, comparison to people you don't know — aren't actually structural. They're optional. The work is figuring out which hierarchies you've consented to that are slowly poisoning you, and quietly stepping out of them.
Third: relationships buffer it. The baboons that fared best, even at lower ranks, were the ones with strong social ties. Friends. Grooming partners. Connection isn't a luxury for stressed primates. It's medicine.
So the takeaway from thirty years in the Serengeti is, weirdly, pretty close to what your grandmother would tell you. Watch what you're letting rank you. Spend time with people who actually love you. The cortisol will know the difference.