Cooking Changed the Size of Our Brains | Richard Wrangham | Big Think

Cooking Changed the Size of Our Brains

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We have the smallest guts of all primates, and the biggest brains. Blame cooking.

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Richard Wrangham:

Richard Wrangham is a professor of biology and anthropology at Harvard University who studies chimpanzees, and their behavior, in Uganda. His main interest is in the question of human evolution from a behavioral perspective. He is the author, with Dale Peterson, of "Demonic Males: Apes, and the Origins Of Human Violence," and "Catching Fire: How Cooking Made Us Human."

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TRANSCRIPT:

Question: How does cooking play a part in evolution?

Richard Wrangham: Well, cooking is a huge influence on the availability of energy. And ultimately, cooking does much more than provide energy, but the first great thing it does, which has not amazingly been appreciated until very recently, is that cooking gives us more energy than eating our food raw. And when our ancestors first learned to cook, then the great huge initial impact would have been that they got so much more energy that they would have had more babies than they had before. And their babies were to survive better, and the adults were to survive better simply because they were able to eat more and have more regular menstrual cycles and put more energy in the immune system. So, the first big thing about cooking is, it gives us a huge increase, but we don't know yet how much. But a big increase in how much energy we get out of our food.

When I was studying chimpanzees, I would normally take sandwiches with me, but there were days that, for one reason or another, I didn't, and because I was studying the feeding behavior of chimpanzees, I would regularly eat what they eat. If I eat everything that they eat that I could find. And on the days when I didn't have any prepared food with me, I would try to rely on what they eat. And you can eat it in the sense that you can chew it up and try to swallow it. Some of it is very strong tasting, which is kind of code word for really unpleasant, and some of it is okay. But it was not possible to find anything that I could fill my stomach with.

Well, the short story is that I realized after a bit that I simply could not get enough energy out of a chimpanzee diet, and then I started thinking, well what would be the best place that you would get a raw diet in the wild? And there may be better places that the chimpanzee forest, I don't think there are many. And this sent me off looking for the difference between humans and other animals in terms of their ability to survive on raw food. And I very rapidly discovered that although there are some myths to go in the opposite direction, humans are different from other species because we have adapted biologically such that we cannot survive on raw food in the same way that other animals can.

In some ways I shouldn't say we cannot survive, but we can't survive in the same way other animals can in this sense that whatever environment we are in, raw food is an unsatisfactory source. And the most dramatic example of this is that in the best study of the people who choose to live on raw food in modern urban environments, which is a great way to lose weight and can be very healthy and takes a lot of will, but is nevertheless has got many admirable aspects, but in the best study of people who do that, then first of all, a high proportion of people suffer energy shortage. They just are not getting enough energy to be able to maintain their bodies well. And the most dramatic point is that half of the women who eat all of their food raw are amenorrheic. That means that their ovarian system is closed down completely. Now, this is despite the fact that they are under ideal conditions. They are eating the best possible kind of foods being domesticated. There are no seasonal food shortages because they're eating from the global food resource; when it's not available in Germany, you can get it from Israel. They're eating food that is processed by blending and grinding and many raw foodists are even drying up to 114 degrees Fahrenheit and they're taking relatively little exercise compared to if you're gathering in the hot sun.

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