Many people from a range of scientific disciplines have put forth an answer to the following grand question: what made us human? Surprisingly, many of these brilliant scientific minds overlooked a simple thing that most of us do everyday, i.e., cook (or at least eat cooked food). In his book, Catching Fire, the biological anthropologist Richard Wrangham (of Harvard fame) takes a stab at answering the grand question by putting forward what he calls “the cooking hypothesis”. And his argument that cooking is what made us human is quite compelling.
Scientific evidence shows that 1.8 million years ago, the first apes learned to cook. But why are we the only apes that eat cooked food today?
Like many others, I think the answer to living better today can be found in our evolutionary past, but thanks to myriad cognitive biases in conjunction with the narrative fallacy, we have a tendency to grossly deceive ourselves. For example, both the raw meat eating Paleo dude and the new-age raw vegan hipster are making the same mistake. Both seem to embrace a teleological argument that concludes that humans weren’t meant to evolve beyond how they were, say, 10,000 years ago. Accordingly, they think they are improving their health through avoiding something that may turn out to be fundamentally human and essential to our well-being (i.e., cooking). Through their ability to craft a believable paleolithic narrative they have convinced themselves that it’s the other people who don’t get it.
It’s undeniably true that humans need food in order to live, but what do we really know about how we are supposed to eat? Or what we ate in the past? What role (if any) did cooked food play in our evolution? These types of questions are inherently difficult to answer with fact due to the scant record of evidence and the diversity that ranges across the human species. The problem with making grand theories about the past is that they often rest on too few facts. Evolution is a fact, but why and how it occurs still remains in the territory of theory. The fact of the matter is that we don’t know what made us human, but Wrangham’s cooking hypothesis (flawed as it may be) is an important narrative to consider.
So what do we know about cooked food? Most importantly, we know that cooking increases the amount of energy our bodies obtain from food. Surprisingly few Americans have heard of this experiment, but the BBC once persuaded a dozen people with high blood pressure to go on an “Evo Diet” at the Paignton zoo (this diet consisted of consuming raw food just like our ape cousins). The results were surprising. Even though the participants consumed massive amounts of raw food, it did wonders for improving their blood pressure and waistlines. It’s important to note that this was a short-term experiment and in all likelihood these participants would have eventually crossed into harmful territory without cooked food. Nonetheless, there is an important lesson to take away. Caloric deprivation, whether from pure fasting or simply eating very little, seems to provide health benefits.
Wrangham points out that cooking food fundamentally alters its caloric value and the nutrients we can absorb from it. This likely explains why primitive hunter-gatherers simply can’t survive on a purely raw-food diet. The human digestive system simply cannot consume enough calories and nutrients from raw food alone. Wrangham’s idea is that the extra energy that comes from cooked foods gave the first cooks biological advantages, and ultimately reproductive advantages, that can be explained by the theory of natural selection.
For as much as the cooking hypothesis makes sense, I think it needs to be considered in conjunction with many other hypothesis as well (e.g., the Man-the-Hunter hypothesis). What made us human is most likely a complex intersection of many things. My own speculations are that both cooking and meat-eating were an integral part of the human enterprise. Wrangham, however, seems to naively downplay the importance of meat eating. “Meat eating”, he writes, “has had less impact on our bodies than cooked food”. He goes on to say that “Even vegetarians thrive on cooked diets. We are cooks more than carnivores.” However, it’s far too easy to get the causation backwards in these just-so narratives. In other words, are we cooks because we’re carnivores or are we carnivores because we’re cooks?
The very thing that Wrangham suggests made us human may also be the very thing that makes a sucker for this narrative. Nonetheless, speculative as it is, Wrangham’s theory is fascinating food for thought.