18. Robert Sapolsky: “I Don’t Think We Have Any Free Will Whatsoever.”

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1:23he's found the time to write a half dozen best-selling and critically acclaimed books. Welcome to People I Mostly Admire with Steve Levitt. This will be my first time talking to Robert Sapolsky, and I'm really curious to see what it's like. I've read every one of his books, so in an odd way he feels like a friend, even though I've never met him or even heard his voice. In pictures, he's got a big white beard and long curly hair that would make Santa Claus jealous, which has led me to make all sorts of assumptions about how he'll speak and even about his personality. We shall see if looks are deceiving.

1:59Now the two topics I want to cover for sure today are stress in humans, and that's a topic on which he's an expert and I am absolutely not an expert, and violence, where we both might have legitimate claims to be experts, although we've approached the issue from opposite perspectives. I suspect those two parts of the conversation will be very different. But before we hit those topics, I want to hear about the baboons.

2:34Robert, so good to meet you. Same, a big fan. So you grew up in an Orthodox Jewish family in New York City, and then you graduated summa cum laude from Harvard. And I'm not sure I can think of a worse preparation than that for spending years in the wilds of Kenya living with baboons. Well, I think that's a pretty good summary of things. At the time I first went out to Africa, which was about a week after graduating college, I had been as far north as New Hampshire and as far south as Washington, D.C., and that was about it. And once while I was backpacking on the Appalachian Trail, I had to stay very still while a porcupine walked past.

3:15And basically, that was the extent of my preparation for going out there. And so what, you had found a professor who thought you would be good at observing baboons? Yeah, this was actually this guy, Irvin DeVore, who was sort of the king of baboons for a long time. And pathetically, I had been writing fan letters to him since I was about 12 years old. and eventually to go sit at his feet at college for four years. At graduation, he shipped me off to go essentially inherit a troop from one of his grad students who was finishing up at the time. So I was gifted my baboons, and I stuck with them on and off for 33 years.

3:59Just describe what a day was like with the baboons, especially at the beginning. It must have been quite odd. What I was trying to understand with the baboons was a physiological question, which was, what does your social rank, your social status have to do with how healthy you are? My world with the baboons consisted of 95 % of the time doing this basic Jane Goodall scene where you get up and you find your baboons and you spend 12 hours a day following them around and noting who's not getting along, who's snarling at someone else, and who's messing with who in the bushes. And then the remainder of the time, what I'd be doing is darting the baboons, using a blowgun anesthetic system to knock them out and then do the same sort of clinical workup that would be done on a human, trying to find out how's his metabolism, how's his blood glucose, how's his stress response, all of that.

4:58If you're trying to study stress in baboons, it seems like shooting them with a blowgun is probably a stressful activity for them. Do you not worry about the effects on your measurements? That was basically the bane of my existence because, yes, the darting process would be stressful. And over the subsequent half hour or so, their bodies would mount a classic endocrine stress response. And what that meant was I had to dart guys when they were not already stressed about something else. So I could not dart somebody if he had a fight that morning, if he had mated, if he was sick, if he was injured, among other things.

5:41I could not dart him if he knew I was trying to do it. These were animals I was spending all day long with just following around with walking stick thing, which every now and then would turn into a blowgun instead and get somebody in the rear when he wasn't looking. You just spent a ridiculous amount of your waking hours thinking about darting strategies and how to think like a baboon and smell like a baboon and just how to look nonchalant around baboons. And so when you darted them, they would fall over or it took a while? You aim for their voluminous rear ends that have lots of meat on it. He'd react as if a bee had stung him or sat on a thorn.

6:22Get up, scratch his rear for a second or two and go back to what he was doing. And then about a minute later, he would sit down. And somewhat oddly, the anesthetic that I used was phencyclodine, also known as PCP, also known as angel dust, which meant I was spending a lot of time filling out forms and being interviewed by skeptical agents from the Drug Enforcement Agency. So what you would see, maybe 30 seconds before the guy would go down, he'd be making facial expressions at other baboons who were not there. Suddenly, plop, he goes down, and you quickly run in and get a first blood sample as fast as possible.

7:03Had they been darting the baboons before you got there, or was that your own invention? in. The approach that I used was pretty much my own. And I spent my first year out there kind of working out the techniques for doing this, which is to say, finding out all the ways in which it didn't work. And I assumed leading up to it, as if a guy ever went down in the middle of the troop, and I was trying to get him into the back of my Jeep, and I'd have 40 baboons trying to rip my throat open defending him. And that turned out to be nonsense. That never happened. What happens instead is you dart number three in the hierarchy and number four has no idea what's happening but decides what a wonderful time to slash number three's throat open yeah so i was not having to defend myself from the baboons i was having to defend the guy i had darted what was striking was you could see developmental stages and cognitive maturation and stuff you could see exactly what stage baboons were at in that they're pretty smart, but you cover something and it no longer exists.

8:09So they'd be all circling around the anesthetized guy and I'd slither in and throw a burlap sack over him and he's gone. He's gone. And I could pick him up. And if inadvertently, like one foot stuck out, everybody suddenly is crazed and snarling again and quick cover the foot and he's gone. He doesn't exist anymore.

8:34Were you close emotionally with the baboons? Yes and no. I was interested in understanding stress-related disease in humans. And very few of us are getting high blood pressure because we're being menaced by tigers or we're physically fighting somebody for a parking spot. What we have instead as westernized humans is we live well enough and long enough to be able to wallow in psychological stress that we have invented. The punchline of the whole field of stress and disease is that we humans turn on the exact same stress response as does a blizzard or a fish or a bird, this ancient, ancient piece of wiring for like running away from a predator or running after a meal, and we turn it on for psychological reasons.

9:25And that's not what it evolved for. And if you do that because of chronic psychological stress, you're going to get sick. So the issue was to try to understand a non-human model for westernized psychosocial stress, and baboons are perfect for it. If you're a baboon, you want to live in the Serengeti, which is where I was doing my work. You live in these big troops, 50 to 100 animals or so. None of the predators mess with you. And most importantly, it's like such a great ecosystem that you only have to spend about three hours a day foraging to get your calories. And what that means then is you have nine hours of free time every day to devote to being absolutely awful to some other baboon.

10:13They had hours and hours of free time each day just to devote to generating psychosocial stress for each other. They were perfect models for westernized human stress. I think what I'm saying is they're completely skeevy, violent, backstabbing animals who are really awful to each other. So they're kind of hard to like. But nonetheless, a number of them I certainly got around to loving over the years. Were you afraid? Were they not violent towards you? You learn who's in a bad mood each day. You don't inadvertently stumble between a mother and her kid. They kind of knew I was something familiar, but not quite a baboon.

10:56If you're some poor, schnook, low-ranking male baboon, and somebody high-ranking who's in a bad mood is heading towards you and you're clearly about to be pummeled, what you do is you look around in this very unlikely hope that somebody will come and help you. Someone will form a coalition with you. And there's a very distinctive facial expression that a baboon would give in that case, sort of a solicitation gesture, come join my hopeless cause here. And this one time, there was this squirrely kid. He had recently joined the group. He didn't really know anybody. And some high-ranking guy was clearly coming over to pound him for no reason.

11:34And you could see he did this solicitive face-pull expression thing to a bunch of the other baboons who were having none of it. And you could see at the very last second, he did this kind of desperate Hail Mary calculation and looked at me and did a face-pull at me. Like saying, okay, it's so bad that I'm even going deep into the bench here. I was like the primate of last resort for the guy to back him up. Shamefully, I pretended I didn't know what he was saying rather than rolling over the other guy with my Jeep or something. Is there a reason why you were only studying the male baboons? All of my physiology, I did exclusively on the males for a very particular reason.

12:19If you're a male baboon, around puberty, you get bored with everyone in the same damn baboon troop you've been grooming since birth. And you pick up and you leave and you go join another troop. In other words, in any troop of baboons, all of the adult males grew up someplace else and showed up around adolescence. In contrast, female baboons spend their whole life in the same troop, and their dominant system is hereditary. So, in other words, you were sitting there surrounded by sisters and nieces and aunts and mothers. So, your daughter, male, and he falls over unconscious. And the main thing you have to do is keep one of his rivals from trying to slash him open.

13:04You dart a female and her mother and her three sisters and her grandkids are trying to shred your vehicle. And it was much, much more dangerous darting the females than the males. So for that, I did most of my physiology on the males. The females were much scarier than the males, despite being about a third the size. So what were the most interesting things you discovered over these decades that you studied the baboons? I went out there when I was 20, and I think by any definition, a very sallow, sort of superficial, sub-adult male primate. And I went out there with the conviction that what I was going to discover in my studies was if you're a male baboon and you have a choice in the matter, you want to be a high-ranking male.

13:52And in retrospect, I was asking the totally wrong question. If you're a male baboon and you have a choice in the matter, would you rather be a high-ranking male baboon or would you rather have friends, social affiliation, which is going to do better things for your longevity, your blood pressure, etc.? And it took me about 20 years to become clear in the fact that absolutely every time go for friends rather than high dominance rank. It turned out the amount of time you spent socially grooming was far more predictive than the amount of time you spent successfully terrorizing somebody else. If you had an upbeat personality, if you saw the watering holes as half full instead of half empty, your physiology, independent of your rank, was going to be so much healthier than someone who saw threat and provocation everywhere.

14:44So in the end, you're saying living a happy life had a positive spillover physiologically for a longer life at Better Health.

14:58You spent so much of your life with these baboons and it came to an end and the end really wasn't pretty. That must have been devastating emotionally for you. Yeah, it was. This was about 15 years into my work in the late 80s, early 90s or so. And to make a long story much shorter, essentially what happened was there was an outbreak of tuberculosis among my baboons. and in non-human primates, TB is the most damn terrifying infectious disease you could imagine. It spreads like wildfire. People absolutely panic when there's a TB outbreak in captive primate populations. It turned out it was due to tubercular meat being sold to the butcher at a nearby tourist lodge.

15:48The butcher was being bribed to approve tubercular cows and he would butcher them. And if there were some really unseemly looking lungs or things like that, he would toss them to the waiting baboon. So that started a TB outbreak and it spread into my troop and it killed half my males. And it was pretty awful. I couldn't go anywhere near this area for years afterward because it was all way too upsetting. I did another 18 years or so of research with the baboons. I started with a different population of troops 60 miles away. I couldn't go anywhere near this area for years afterward because it was all way too upsetting.

16:33It was a few of my favorite animals in the original troop that got done in by TB. first world tragedy, though, in terms of one having the luxury to be able to expend, like, love and a sense of bereavement on a troop of non-human primates in the world there, where there's a whole lot of other things to be bereaved about. But nonetheless, that hit me pretty hard.

17:01You're listening to People I Mostly Admire with Steve Levitt and his conversation with primatologist Robert Sapolsky. After this short break, they'll return to talk about Robert's work on chronic stress and violence.

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19:25I've never said this publicly before, and it's not something you're supposed to say, but I think I like animals more than I like people. I've been thinking a lot lately about why humans elevate the welfare of humans so far above the welfare of other species. And the more I think about it, the less sense it makes to me. So in the second half of the interview, I'd like to see what Sapolsky's thoughts are on this, and then dive into his research on stress and finally get to violence.

19:56At the risk of getting you into big trouble, let me ask you something. Let's see, we're faced with a difficult moral choice. There was a human and a baboon, and they were both going to be killed, and you could only save one. Anonymous baboon and anonymous human. Which would you say? Being a professor, an academic, I think the only answer I can give you is I was write a paper on the subject and try to get it published somewhere. I think that's the only response I would have to a real life situation. So you would say the baboon, but you just can't say that in public. Possibly. It really would depend on the baboon.

20:33And I suppose on the human. Have you thought about why humans put so much value on other humans relative to different kinds of life? Well, like most primates, we have a very strong tendency to divide the world into us and them. There's a neurobiology of it showing that a part of your brain called the amygdala, which is about fear and anxiety and aggression, your amygdala is doing us-them distinctions in under a tenth of a second before you're even consciously aware of who you're looking at. So like every other social primate out there, we do us-them with a real propensity towards being a whole lot nicer to the us's than the them's.

21:15And it's clear that your average human has obviously a big us-them divide between humans and other species. unlike a baboon no matter what a baboon thinks it is going to view a leopard or a hyena as a truly terrifying them and it's going to look at a male baboon from another troop as a suspicious them and there's no way they can ever decide that oh they had all these bad sort of preconceived notions about hyenas and they're actually okay guys humans change their categorizations we can have multiple ones in our heads. And one of the weird ones that lots of people have is, on some visceral level, considering some of our pets to be as much family as our real human families.

22:06And you sure could not explain that to a baboon, but there's been amazing physiological studies showing human-pet interactions that are not supposed to be occurring between different species, and yet they do. There was a paper published some years ago, a survey of people with almost the exact scenario. Aha, there's a dog and a person. They're both about to be hit by a bus. You could save only one of them. Which would you save? And you saw a huge gender difference in that women were far more likely to vote for saving the dog over the human. I spent some time in India once, and part of that I was in a national park trying to see tigers, and we were riding around with one of the park rangers and I asked him whether he had a gun.

22:54And he said, oh yeah, I carry a gun. And I said, what would make you shoot a tiger? And he said, shoot a tiger? I would never shoot a tiger. We aren't allowed to shoot tigers. And I said, what if the tiger was attacking you or some other people? I said, no, even if the tiger were attacking, I could shoot the gun in the air, but I would never shoot the tiger. I said, well, what if an American tourist were there? Then I'm sure you must shoot the tiger to save the American tourist. And he said, no, we wouldn't do that. And eventually he told me, actually, with the tigers, it's not until they kill two or three villagers that they go and find the tiger and then sedate him and put him somewhere else.

23:31So it basically will not kill a tiger no matter what. And in a weird way, forgetting about your us versus them categorization psychologically, to India, really, these tigers are scarce and they're valuable. But it was the first time I've ever heard stated out loud a public policy that simply said that these animals are more valuable than humans, no matter how these animals behave. Yep. The explicitness of that is pretty extraordinary. Do you remember in the Cincinnati Zoo, there was a gorilla who picked up a boy who had fallen in and the shot and killed the gorilla quite quickly. Does that surprise you, that decision?

24:08That was Harambe. I met Harambe once. I remember being devastated when that happened. It was a circumstance where one could pretty easily be quite critical of the parent who was not watching the kid enough to keep them from climbing over something they shouldn't have climbed over. There was absolutely no suggestion that Harambe was going to harm the kid, but if Harambe had decided to do so, it would have been disastrous, or even Harambe, with the best of intentions, could have been catastrophically damaging to the kid. So on some level, it was a necessary decision. When I met Harambe, I had met the guy who had to make the decision to pull the trigger.

24:56And I can imagine how agonizing that was for him. And that was the correct decision. But every possible outcome there was heartbreaking.

25:16Anyone who isn't familiar with your research and just listened to these amazing stories about the baboons, I think they'd be shocked to discover that along the way you have been really having an incredible career doing cutting-edge science in a more standard lab setting. Your view, I think, is that chronic stress is a horrible silent killer and health destroyer. Is that correct? Absolutely. The word stress got introduced into the medical literature about 90 years ago, and there's been sort of a wave of what people first learned was this stress stuff is terrible for your stomach walls and is bad for your cardiovascular system and eventually bad for your immune system and reproductive system.

26:00And when I started work in this area in the early 80s, as a neurobiologist, we were just beginning to explore that stress does some pretty lousy stuff to your brain as well. And one of the things that became clear in that period was looking at the fact that there's a class of neurons in the brain that are killed by chronic sustained stress. And it's got something to do with brain aging and aspects of cognitive decline during aging. So a lot of what I've spent my eight months a year when I wasn't with the baboons was trying to understand what stress does to the nervous system, how it damages it, what you can do about it.

26:39And eventually my lab was designing gene therapy techniques to try to make neurons more robust in the face of stress. And it was a very different way of thinking about science and stress than slithering around trying to sneak up on a baboon. So you talk about stress as if it just exists, but it strikes me that most of the stress people feel is just self-generated. I'll give you an example. So my son was a good fencer, a world-class fencer as a teenager. Nobody actually cared. Like, no one cared how he did his tournaments. But he was so consumed by stress from these events that he eventually dropped the sport.