Transcription
What is your book titled, Goodness Paradox? What are the main ideas in this book?
Well, the paradox is the fact that humans, uh, show extremes in relationship to both violence and non-violence. And so, the, um, the violence is that we are one of these few animals in which we, uh, use coalitionary proactive violence to kill members of our own species, and we do it in large numbers, just like a few other species. And the non-violence is, we're particularly extreme in how repressed we are in terms of reactive violence. And I, I told you the story of of how we get there, you know.
So, what's so extraordinary about us is that, uh, most animals are either high on both or relatively low on both. So, chimpanzees are high on proactive violence and reactive violence. Bonobos are less than chimpanzees on both of those, but still hundreds of times more reactively aggressive than humans are. What we've done is retain, uh, proactive violence being high and got reactive violence really being low. And so, we have these wonderful societies in which we're all so incredibly nice to each other and tolerant and calm and can meet strangers and have no problem about, um, leading to any kind of, uh, conflict. At the same time as we are one of the worst, uh, killing machine species that's ever existed.
So, what's so extraordinary about this is that if you look at the political philosophers of the last few hundred years, you've got this fight famously between Thomas Hobbes and Jean-Jacques Rousseau, or literally, you've got the fight between their followers, you know. So, the followers of Hobbes say, well, Hobbes was right because he says that we are naturally violent and you need a Leviathan, a central government or king, to be able to suppress the violence. So, we're naturally hurried and we can learn to be good. Whereas Jean-Jacques Rousseau is interpreted as saying the opposite, that we are naturally good and it's only when culture intervenes and and horry like your ideologies come in that we become uncivilized. And so, people have have had this endless fight between, are we naturally corrupt or are we naturally kind? And and that has gone on, you know, for years. And it's only in the last two or three decades that anthropologists like Christopher Baume and Bruce Naft have said, look, you know, it's obvious what the answer is. We are both of these things.
And what is so exciting now is, I think we can understand why we are both. And the answer is, we come from ancestors that were elevated on proactive aggression, that were hunters and killers, both of animals and of each other. And you've got to include that as almost certain, uh, from the past. And, um, and then now we've we've taken our reactive aggression and we've down-regulated it. And that's given us power. It's given us power because once you get rid of the alpha male, once the beta males take over and force selection in favor of a more tolerant, less reactively aggressive individual, the effect is that our cultures suddenly become capable of focusing on things other than conflict. And so, we have social groups in which individuals, instead of constantly being on edge in the way that chimpanzees are with each other, um, are able to interact in ways that enable them to share looking at a tool together, or share their food together, or pass ideas from one to another, or support each other when they're ill, or whatever the issue is, cooperate in ways that make the group far more effective.
So, you asked earlier, you know, what did I think about why sapiens was able to expand at the expense of Neanderthals so dramatically around 40,000 years ago? And the answer is, uh, that whatever it was, it had something to do with the sapiens ability to cooperate. That was what gave them bigger groups. That's what enabled them to have a far more effective way of living. And I suspect it was to do with the weapons and and military aspects. But even if it wasn't that, that the greater cooperation that sapiens were showing, uh, would have been hugely important. So, sapiens then had groups of, uh, you know, who knows exactly how big they were, but, uh, uh, scores of of people, uh, to judge from their remains. Uh, whereas Neanderthals were living in widely separated small groups of, you know, maybe maybe as many as 15 or 20 people sometimes, where they saw others so rarely that they were inbreeding at high levels, you know, fathers, uh, having babies with their daughters. Very different world. Very different world. And that's probably what our world was like before we got sapiens, before we got serpents. And it's fascinating that there was that kind of violence against.
So, once you get the get rid of the alpha males, you have now the freedom to, uh, to have kindness amongst the beta, the beta males. Like, not not kindness, but collaboration. That's the better word. Yes. Right, right. Much more collaboration, not just among the males, but among the females, but also among the gamma males and the, uh, and the females. Yeah. I don't know what a gamma male is, but I imagine there's a whole alphabet. Well, I don't know about hello enough, but I think the the big letters are the married men, yeah. And and the and the unmarried men. Ah, you know, because now the married men were had a problem with the unmarried men, right? I mean, you you see it in ethnographies of hunters and gatherers recently, where, uh, the unmarried men would be given rules such as, I mean, the very extreme rule in northern Australia was, uh, you cannot come to the camp, uh, for months. You have to go away and live, uh, somewhere out in the bush. Yes, because we don't want you anywhere near our wives. And, and then another kind of, you know, rule is, um, if you are in the camp, you must be in the firelight all the time, otherwise we don't know what you're doing out in the dark. So, your real efforts to control them, because, you know, the men who had lots of wives did not want those horrid bachelors sneaking around.
I love this. You also wrote the book titled, Catching Fire: How Cooking Made Us Human. What's the central idea in this book?
The subtitle, How Cooking Made Us Human, refers not to Homo sapiens, but to Homo erectus. So, human there means the genus Homo. And Homo erectus is the first full member of the genus Homo in the sense that it looked like us, just with a sort of slightly robust, more robust build and a smaller brain. And the central idea of Catching Fire is that it was the control of fire that was responsible for the emergence of Homo erectus, and therefore the genus Homo, which happened two million years ago. And it was an evolution from a, um, a line of Australopithecines. And Australopithecines are the creatures with which, um, from whom we evolved. They were present in Africa from something like six or seven million years ago up to, actually, up to one million years ago. And then a branch led off to Homo around two million years ago.
And the way to think of Australopithecines is that they were like chimpanzees standing upright. So, they were erect, bipedal walkers. They were like chimpanzees in the sense that they had brains about the size of a chimpanzee. They were literally about the body size of a chimpanzee, a little bit smaller, actually. And they had big jaws because they were still eating raw food. They had big teeth and big jaws. And then around two million years ago, the line of Australopithecines, which ended with an intermediate species, a kind of missing link area, because it's not missing, called, uh, habilis, sometimes called Homo habilis, but more properly, I, in my view, call Australopithecus habilis, that gave rise to Homo erectus.
And Homo erectus, here's how different it was. It had a smaller mouth, a smaller jaw, smaller teeth, and to judge from its ribs and pelvis, smaller gut. In addition, it had lost what Australopithecines all had, which was adaptations for climbing in the trees. And that meant that Homo erectus must have slept on the ground. And since it slept on the ground, it should have been able to defend itself somehow against predators. And I can't think of any way they could have done that unless they had fire.
So, there are two major clues to why it was with Homo erectus that our ancestors first acquired the control of fire. One is the fact that they were clearly not sleeping in trees in the way that chimpanzees and gorillas and bonobos and all the other primates do. And the other is that there was this striking reduction throughout the gut, reduction in size of the mouth and the chewing apparatus, and in the gut itself. And that conforms to what we see nowadays about humans, which is that our guts are about two-thirds of the size of what they would be if we ate raw food, to judge by the great apes. So, at some point in our revolution, we acquired the skill of cooking, the skill of controlling fire. At no time between two million years ago and the present do we see any changes in our anatomy that can, as it were, justify the enormous change that happens when you are an animal that learns to control fire. But at two million years ago, we have exactly what you'd expect, namely the guts becoming smaller because the food is becoming softer and much more easy to digest. So, you don't have to work so hard in your body to digest it. And as I say, um, commitment to sleeping on the ground, which I think you'd be absolutely crazy to do nowadays on a moonless night in the middle of Serengeti unless you had fire. I've slept out quite a lot in various parts of Africa, in the bush, and you will not catch me just lying on the ground, um, in an area with lots of predators, unless I got a fire with me. You're going to get eaten. You're going to get terrified and you're going to get eaten.
Okay, so there's a million questions I want to ask. So, one is, is it very naturally coupled, the discovery of controlled fire and cooking with fire? Is that an obvious leap?
Well, here's what we know. We know that, uh, all the animals that we've tested like to eat their food cooked more than they like it raw. Okay? So, this is true for all the great apes. You know, we've tested them.
That's fascinating, by the way. Why is that? That's just like a property of food, I suppose?
Yes, I think what it is is that, um, animals are always looking for any kind of way to get food that is easier to digest. And there are various signals in the food, such as the amount of sugar there, the amount of free amino acids, because the amino acids can be tasted, um, and the physical qualities of the food be particularly important. How tough the food is, always prefer softer food, provided it it feels safe, you know, it tastes safe. And these kinds of, uh, sensory cues, uh, are all there in cooked food. You know, it's, uh, it's soft, it doesn't have so many, uh, toxins, it's not so noxious to taste, easier to chew. So, everyone loves it spontaneously. Your dogs and your cats prefer cooked food to raw food. Well, maybe you can say that's a consequence of domestication. But even, you know, as I say, all the great apes you test, naive ones, and they prefer it cooked if they can. So, so then obvious, once you have fire, you're going to accidentally discover that food changes when you apply fire to it. And then there's going it's going to be the crea, the big crazy new fad.
Yeah, you took the words out of my mouth. I mean, if if they have fire at all, and you know, their food rolls into it, five minutes later, it tastes better than before.
How big of an invention, from an engineering perspective, do you think is the discovery of fire? Do you do you think, uh, for the, uh, for Homo erectus, Homo sapiens, do you think it's the greatest invention ever?
Yeah, I think I think that that, uh, the control of fire has been ultimately responsible for essentially, uh, how grandiose do I want to be here, you know, the entire human story, uh, going back to Homo. Is what changed us from being a regular kind of animal? And perhaps the biggest way in which it is likely to have changed us is it reduced the difficulty of making a large brain. So, you know, the story here is that the constraints on brain size are energetic. You and I have brains that are something like 2.5% of our body weight. It consumes around 25% of all of our calories. So, it's disproportionate. There are other expensive organs in our body as well, such as the heart. And what's different about their brain is that in addition to us being able to fuel it in a way that other animals can't, we also have reasons for wanting to have an even bigger brain, whereas we don't want an even bigger heart. So, what those reasons are is unclear. But, um, with regard to the costs of maintaining a brain, cooking makes it possible because it's supplying, uh, more calories and it is enormously reducing the amount of time that it takes to chew your food.
So, if you were a gorilla and you wanted to have a bigger brain, you might say, okay, well, let's just eat some more. But gorillas are eating for pretty much the entire day, in the sense that they are eating for maybe seven or eight hours a day. In some seasons, that's just chewing. And then they've got to sit around and digest their food because they can't just eat all the time. They've got to take a break while the food is digested in the stomach and then passed into the gut. So, the stomach is already full. So, basically, gorillas are eating about the maximum rate already. So, how does a gorilla get a bigger brain? It doesn't. It's actually got a smaller brain relative to its body size than a chimpanzee does. And and that's the basic problem for our ancestors. Then you come along and cook, and all of a sudden you can get an increased amount of energy from your food. You are spending much less energy on digesting your food. You know, there are 25 bodily processes or more that are involved in digesting your food, making the acid that takes the proteins apart, maintaining the brush border where the molecules are taken across the gut wall, and so on. That all costs. It costs you to digest your food. It costs less if you cook your food. So, you get a net gain in the amount of energy. And you are reducing the amount of time from, uh, in our case of our ancestors, probably around 50% of the day to chewing, to nowadays, one hour a day chewing. So, all of a sudden, you've got hours a day in which to do other things and to use those those brains that you've now enabled to grow. So, with Homo erectus, you start the process of getting a bigger brain. And famously, you know, throughout the whole period of the evolution of the genus Homo, you have a steadily increasing size of brain until right at the end, when it actually gets, it actually gets you.