Richard Wrangham is a biological anthropologist at Harvard, specializing in the study of primates and the evolution of violence, sex, cooking, culture, and other aspects of ape and human behavior. Please support this podcast by checking out our sponsors:
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EPISODE LINKS:
Richard's Website: https://heb.fas.harvard.edu/people/richard-w-wrangham
The Goodness Paradox (book): https://amzn.to/3aqg9tg
Catching Fire (book): https://amzn.to/3FAZAcz

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OUTLINE:
0:00 - Introduction
0:49 - Violence in humans vs violence in chimps 
20:21 - Study of violence in chimps
39:16 - Human evolution and violence 
1:35:45 - The Goodness Paradox and Catching Fire
1:48:02 - How cooking changed our evolution 
2:02:48 - The beauty of the human mind emerges
2:06:54 - A map of how chimps, gorillas, and humans are all related
2:19:26 - Preserving nature
2:27:17 - The meaning of life

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The following is a conversation with Richard Wrangham, a biological anthropologist at Harvard, specializing in the study of primates and the evolution of violence, sex, cooking, culture, and other aspects of ape and human behavior at the individual and societal level.

He began his career over 4 decades ago, working with Jane Goodall and studying the behavior of chimps.

And since then, has done a lot of seminal work on human evolution and has proposed several theories for the roles of fire and violence in the evolution of us, hairless apes, otherwise known as homo sapiens.

To support it, please check out our sponsors in the description.

And now, here's my conversation with Richard Wrangham.

You've said that we're much less violent than our close living relatives, the chimps.

Can you elaborate on this point of how violent we are and how violent our evolutionary relatives are.

Well, I haven't said exactly that we're less violent than chimps.

What I've said is that there are 2 kinds of violence.

1 stems from proactive aggression and the other stems from reactive aggression.

Proactive aggression is planned aggression.

Reactive aggression is impulsive, defensive.

It's reactive because it takes place in seconds after the threat.

And the thing that is really striking about humans compared to our close relatives is the great reduction in the degree of reactive aggression.

So we are far less violent than chimps when prompted by some relatively minor threat within our own society.

And the way I judge that is with not super satisfactory data, but the study which is particularly striking is 1 of people living as hunter-gatherers in a really upsetting kind of environment, namely people in Australia living in a place where they got a lot of alcohol abuse, there's a lot of domestic violence.

It's all a sort of, a society that is, you know, as bad from the point of view of violence as an ordinary society can get.

There's excellent data on the frequency with which people actually have physical violence and hit each other.

And we can compare that to data from several different sites comparing, we're looking at chimpanzee and bonobo violence.

And the difference is between 2 and 3 orders of magnitude.

The frequency with which chimps and bonobos hit each other, chase each other, charge each other, physically engage is some day between 500 and a thousand times higher than in humans.

So there's something just amazing about us and you know this has been recognized for centuries.

Aristotle drew attention to the fact that we behave in many ways like domesticated animals, because we're so unviolent.

But, you know, people say, well, what about, you know, the hideous engagements of this 20th century, the First and Second World War and much else besides.

You know, all of that is gangs of people making deliberate decisions to go off and attack in circumstances which ideally, the attackers are going to be able to make their kills and then get out of there.

That's the ordinary way that armies try and work.

And there it turns out that humans and chimpanzees are in a very similar kind of state.

That is to say, if you look at the rate of death from chimpanzees conducting proactive coalitionary violence, It's very similar in many ways to what you see in humans.

So we're not downregulated with proactive violence, it's just this reactive violence that is strikingly reduced in humans.

So chimpanzees also practice kind of tribal warfare.

So this was discovered first in 1974, it was observed first in

which was about the time that the first major study of chimpanzees in the wild by Jane Goodall had been going for something like 5 years during of the chimpanzees being observed wherever they went.

Until then, they'd been observed at a feeding station where Jane was luring them in to be observed by seeing bananas, which is great.

But she didn't learn what was happening at the edges of their ranges.

So 5 years later, it became very obvious that there was hostile relationships between groups.

And those hostile relationships sometimes take the form of the kind of hostile relationships that you see in many animals, which is a bunch of chimps in this case, shouting at a bunch of other chimps on their borders.

But dramatically, in addition to that, there is a second kind of interaction, and that is when a party of chimpanzees makes a deliberate venture to the edge of their territory silently, and then search for members of neighboring groups.

And what they're searching for is a lone individual.

So I've been with chimps when they've heard a lone individual under these circumstances, or what they think is a lone 1, and they touch each other and look at each other and then charge forward, very excited.

And then while they're charging, all of a sudden, the place where they heard a lone call erupts with a volley of calls.

It was just 1 calling out of a larger party.

And our chimps put on the brakes and scoot back for safety into their own territory.

But if in fact they do find a lone individual and they can sneak up to them, then they make a deliberate attack.

They're hunting, they're stalking and hunting, and then they impose terrible damage, which typically ends in a kill straight away, but it might end up with the victim so damaged that they'll crawl away and die a few days or hours later.

So that was a very dramatic discovery because it really made people realize for the first time that Conrad Lorenz had been wrong when in the 1960s, in his famous book on aggression, he said warfare is restricted to humans, animals do not deliberately kill each other.

Well, now we know that actually there's a bunch of animals that deliberately kill each other, and they always do so under essentially the same circumstances, which is when they feel safe doing it.

So humans feel safe doing it when they've got a weapon.

Animals feel safe when they have a coalition, a coalition that has overwhelming power compared to the victim.

And so wolves will do that, and lions will do that, and hyenas will do that, and chimpanzees will do it, and humans do it too.

Can they pull themselves into something that looks more like a symmetric war as opposed to an asymmetric 1?

So accidentally engaging on their own individual and getting themselves into trouble?

Or are they more aggressive in avoiding these kinds of battles?

No, they're very, very keen to avoid those kinds of battles, but occasionally they can make a mistake.

But so far, there have been no observations of anything like a battle in which both sides maintain themselves.

And I think you can very confidently say that overwhelmingly what happens is that if they discover that there's several individuals on the other side, then both sides retreat.

Well, she's a wonderfully independent, courageous person, you know, who she famously began her studies not as a qualified person in terms of education, but qualified only by enthusiasm and considerable experience, even in her early 20s, with nature.

So she's courageous in the sense of being able to take on challenges.

The thing that is very impressive about her is her total fidelity to the observations, very unwilling to extend beyond the observations, waiting until they mount up and you've really got a confident picture, and tremendous attention to individuals.

So, that was an interesting problem from her point of view because when she got to know the chimpanzees of Gombe, this particular community of Kasekela, about 60 individuals.

So Gombe was in Tanzania on Lake Tanganyika.

She was there initially with her mother and then alone for 2 or 3 years of really intense observation and then slowly joined by other people.

What she discovered was that there were obvious differences in individual personality.

And the difficulty about that was that when she reported this to the larger scientific world, initially her advisors at Cambridge, they said, well, you know, we don't know how to handle that because you've got to treat all these animals as the same basically because there is no research tradition of thinking about personalities.

Well now, whatever it is, 60 years later, the study of personalities is a very rich part of the study of animal behavior.

At any rate, the important point in terms of what was she like is that she stuck to her guns and she absolutely insisted that we have to show, describe in great detail the differences in personality among these individuals and then you can leave it to the evolutionary biologist to think about what it means.

So what is the process of observation like this, like observing the personality, but also observing in a way that's not projecting your beliefs about human nature or animal nature onto chimps, which is probably really tempting to project.

So your understanding of the way the human world works, projecting that onto the chimp world.

Yes, I mean, it's particularly difficult with chimps because chimps are so similar to humans in their behavior that it's very easy to make those projections, as you say.

The process involves making very clear definitions of what a behavior is.

You know, Aggression can be defined in terms of a forceful hit, a bite, and so on.

And writing down every time these things happen, and then slowly totting up the numbers of times that they happen from individual A towards individuals BCD, and E, so that you build up a very concrete picture rather than interpreting at any point and stopping and saying, well, they seem to be rather aggressive.

So the formal system is that you build up a pattern of the relationships based on a description of the different types of interactions, the aggressive and the friendly interactions.

And all of these are defined in concrete.

And so from that you extract a pattern of relationships.

And the relationships can be defined as relatively friendly, relatively aggressive, competitive, based on the frequency of these types of interactions.

And so 1 can talk in terms of individuals having a relationship which on the scores of friendliness is 2 standard deviations outside the mean.

Well, I mean, you know, there will be obviously the friendly ones will be the ones who have exceptionally high rates of spending time close to each other, of touching each other in a gentle way, of grooming each other, and by the way, finding that those things are correlated with each other.

So it's possible to define a friendship with a capital F in a very systematic way, and to compare that between individuals, but also between communities of chimpanzees and between different species.

So that we can say that in some species, individuals have friends and others that don't at all.

What about just because there's different personalities and because they're so fascinating, What about sort of falling in love or forming friendships with chimps?

You know, like really, you know, connecting with them as an observer.

Because you're tracking these individuals that are full of life and intelligence for long periods of time.

Plus, as a human, especially in those days for Jane, she's alone observing it.

I mean, probably deeply lonely as a human being observe these other intelligent species.

And of course, Jane in those early years, I think she's willing now to talk about the fact that she regrets to some extent how close she became.

And the problem is not just from the humans, the problem is from the chimpanzees as well, because they do things that are extremely affectionate, if you like.

At 1 point, Jane offered a ripe fruit to a chimpanzee called David Greybeard.

David Greybeard took it and squeezed her hand as if to say thank you.

And then I think he gave it back, if I remember rightly.

Oh, it's almost like thank you and returning the affection by giving the fruit if they did something like that.

I mean, chimpanzees could squeeze you very hard as occasionally has happened.

Some chimps are aggressive to people and others are friendly.

And the ones that are friendly tend to be rather sympathetic characters because they might be ones who are having problems in their own society.

So Jomio in Gombe used to come and sit next to me quite often, and he was having a hard time making it in that society, you know, which I can describe to you in terms of the number of aggressive interactions if you want, you know, but just to be informed about it.

So all of this is a temptation to be very firmly resisted.

And in the community that I've been working with in Uganda for the last 30 years, we try extremely hard to impress on all of the research students who come with us that it is absolutely vital that you do not fall into that temptation.

Now, you know, we heard a story of 1 person who did reach out and touch 1 of our chimps.

Not because the chimp is going to do anything violent at the time, but because if they learn that humans are as weak physically as we are compared to them, then they can take advantage of it, us.

So after Jane had done the very obvious thing when you're first engaged in this game of allowing the infants to approach her and then tickling them and playing with them, some of those infants had the personality of wanting to take advantage of that knowledge later.

And so, you had an individual, Frodo, who was violent on a regular basis towards humans when he was an adult, and he was quite dangerous.

I mean, he could easily have killed someone.

He killed a baby that he took from a mother, a human baby that he took off her hip when he met her on the path.

So, it's a reminder that we're dealing with a species that are rather human-like in the range of emotions they have, in the capacities they have, and even in the strength they have, they are in many ways stronger than humans.

So in the full range of friendliness and violence, the capacity for these very human things.

Yes, I mean, It's very obvious with violence, as we talked about, that they will kill, they will kill not just strangers.

They can kill other adults within their own group.

Obviously, these killings can't happen very often because otherwise they'd all be dead.

And we're now finding that they can live to 50 or 60 years in the wild at relatively low population density because they're big animals eating a rather specialized kind of food, the ripe fruits.

With friendliness, they are very strong to support each other.

They very much depend on their close friendships, which they express through physical contact and particularly through grooming.

So grooming occurs when 1 individual approaches another.

I might present for grooming, a very common way of starting, turning their back or presenting an arm or something like that, and the other just riffles their fingers through the hair.

And that's partly just soothing, and it's partly looking for parasites, but mostly it's just soothing.

And the point about this is it can go on for half an hour, it can go on for sometimes even an hour.

So this is a major expression of interest in somebody else.

When did your interest in this 1 particular aspects of Chim come to be, which is violence?

When did the study of violence in Chims become something you're deeply interested in?

Well, for my PhD in the early 1970s, I was in Gombe with Jane Goodall and was studying feeding behavior.

But during that time, we were seeing, and I say we because there were half a dozen research students all in her camp.

We were discovering that chimps had this capacity for violence.

The first kill happened during that time, which was of an infant in a neighboring group.

And we were starting to see these hunting expeditions.

And this was the start of my interest because it was such chilling evidence of an extraordinary similarity between chimps and humans.

Now at that time, We didn't know very much about how chimpanzees and humans were related.

Chimps, gorillas, bonobos are all 3 big black hairy things that live in the African forests and eat fruits and leaves when they can't find fruits, and walk on their knuckles, and they all look rather similar to each other.

So they seem as though those 3 species, chimps and gorillas and bonobos, should all be each other's closest relatives, and humans are something rather separate, and so any of them would be of interest to us.

Subsequently we learn that actually that's not true and that there's a special relationship between humans and chimpanzees.

But at the time, even Without knowing that, it was obvious that there was something very odd about chimpanzees because Jane had discovered they were making tools.

She had seen that they were hunting meat.

She had seen that they were sharing the meat among each other.

She has seen that the societies were dominated politically by males, coalitions of males.

All of these things, of course, resonate so closely with humans.

And then it turns out that in contrast to conventional wisdom at the time, the chimpanzees were capable of hunting and killing members of neighboring groups.

Well, at that point, the similarities between chimps and humans become less a matter of sort of sheer intellectual fascination than something that has a really deep meaning about our understanding of ourselves.

I mean, until then, you can cheerfully think of humans as a species apart from the rest of nature, because we are so peculiar.

But when it turns out that, as it turns out, 1 of our 2 closest relatives has got these features that we share and that 1 of the features is something that is the most horrendous, as well as fascinating, aspect of human behavior, then how can you resist just trying to find out what's going on?

So I have to say this, I'm not sure if you're familiar with the man, but fans of this podcast are, so we're talking about chimps, we're talking about violence.

I think a lot of people are fascinated by these topics.

So as you're saying, why do we find the exploration of violence and the relations between chimps so interesting.

Until we had this information about chimpanzees, it was possible to believe that the psychology behind warfare was totally the result of some kind of recent cultural innovation that had nothing to do with our biology.

Or if you like, that it's got something to do with sin and God and the devil and that sort of thing.

But what the chimps tell us after we think carefully about it is that it seems undoubtedly the case that our evolutionary psychology has given us the same kind of attitude towards violence as occurred in chimpanzees.

And in both species, it has evolved because of its evolutionary significance.

In other words, because it's been helpful to the individuals who have practiced it.

And now we know that, as I mentioned, other species do this as well.

In fact, wolves, which this is a really kind of ironical observation.

Conrad Lorenz, who I mentioned, had been the person who thought that human aggression in the form of killing members of our own species was unique to our species.

And in captivity, he noted that wolves are very unlikely to harm each other in spats among members of the same group.

What happens is that 1 of them will roll over and present their neck, much as you see in a dog park nowadays, and the other might put their jaws on the neck, but will not bite.

Okay, so now it turns out that if you study wolves in the wild, then neighboring packs often go hunting for each other.

They are in fierce competition and as much as 50% of the mortality of wolves is due to being killed by other wolves.

The chimpanzees and humans fit into a larger pattern of understanding animals in which you don't have an instinct for violence.

What you have is an instinct, if you like, to use violence adaptively.

And if the right circumstances come up, it'll be adaptive.

If the right circumstances don't come up, it won't be.

So some chimpanzee communities are much more violent than others because of things like the frequency with which a large party of males is likely to meet a lone victim.

that's going to depend on the local ecology.

But, you know, so the overall answer to the question of what do chimps teach us is that we have to take very seriously the notion that in humans, the tendency to make war is a consequence of a long-term evolutionary adaptation and not just a military ideology or some sort of local patriarchal phenomenon.

And of course, a reading of history, a judicious reading of history, fits that very easily because war is so commonplace.

So it's not a construction of human civilization.

So what's the difference between violence on the individual level versus group?

It seems like with chimps and with wolves, there's something about the dynamic of multiple chimps together that increase the chance of violence?

Or is violence still fundamentally part of the individual?

Like would an individual be as violent as they might be as part of a group?

If we're talking about killing, then violence in the sense of killing is very much associated with a group.

And the reason is that individuals don't benefit by getting into a fight in which they risk being hurt themselves.

So it's only when you have overwhelming power that the temptation to try and kill another victim rises sufficiently for them to be motivated to do it.

The average number of chimpanzee males that attack a single male in something like 50 observations that have accumulated in the last 50 years from various different study sites is 8, 8 to 1.

Now, sometimes it can go as low as 3 to 1, But that's getting risky.

But if you have 8, you can see what can happen.

I mean, basically, you have 1 male on 1 foot, another male on another foot, another male on an arm, another male on another arm.

Now you have an immobilized victim with 4 individuals capable of just doing the damage.

so they can then move in and tear out his thorax and tear off his testicles and twist an arm until it breaks and do this appalling damage with no weapons.

What is the way in which they prefer to commit to violence?

Is there something to be said about like the actual process of it?

So if you look at human warfare, there's different parts in history prefer different kind of approaches to violence.

It had more to do with tools, I think, on the human side.

But just the nature of violence itself, sorry, the practice, the strategy of violence, is it basically the same?

You improvise, you immobilize the victim and they just rip off different parts of their body kind of thing?

Yeah, you have to understand that these things are happening at high speed in thick vegetation, mostly, so that they have not been filmed carefully.

You know, we have a few little glimpses of them from 1 or 2 people like David Watts, who's got some great video, but we don't know enough to be able to say that.

It's hard for me to imagine that there are styles that vary between communities, cultural styles, but it is possible.

And 1 thing that is striking is that the number of times that an individual victim has been killed immediately has been higher in Kibale Forest in Uganda than in Gombe National Park in Tanzania.

We don't have real numbers now, but what is this?

I can't remember the exact numbers, but 10 versus 15 or something.

So maybe they damaged to the point of expecting a death in 1 place and they just finish it off in the other, but most likely that sort of difference will be due to differences in the numbers of attackers.

You know, human beings are able to conceive of the philosophical notion of death, of mortality.

Is there any of that for chimps when they're thinking about violence?

Is violence, like what is the nature of their conception of violence, do you think?

Do they realize they're taking another conscious being's life or is it some kind of like optimization over the use of resources or something like that?

I don't think it's, I can't think of any way to get an answer to the question of what they know about that.

I think that the way to think about the motivation is rather like the motivation in sex.

So when males are interested in having sex with a female, whether it's in chimpanzees or in humans, they don't think about the fact that what this is going to do is to lead to a baby.

Mostly what they're thinking about is, I wanna get my end away.

And I think that it's a similar kind of process with the chimps.

What they are thinking about is, I want to kill this individual.

And it's hard to imagine that taking the other individual's perspective and thinking about what it means for them to die is going to be an important part of that.

In fact, there's reasons to think it should not be an important part of it because it might inhibit them and they don't want to be inhibited.

The more efficient they are in doing this, the better.

But I think it's interesting to think about this whole motivational question because it does produce the sort of rather haunting thought that there has been selection in favor of enthusiasm about killing.

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Richard Wrangham: Violence, Sex, and Fire in Human Evolution | Lex Fridman Podcast #229