TLS on Human Cooking

on Cooked Food

One for the pot

by BARBARA J. KING

a review of Richard Wrangham's CATCHING FIRE
How cooking made us human 312pp. Profile. Paperback, £15. 978 1 846682 85 8 US: Basic Books. $26.95. 978 0 465 01362 3

Richard Wrangham, biological anthropologist at Harvard University and expert observer of chimpanzees at field sites in Tanzania and Uganda, sat down to lunch with a trio of raw foodists some years ago. Already a champion of a significant role for cooking in human evolutionary history - an idea that would form the core of his book Catching Fire - Wrangham watched his companions make a curious choice: they refused not only any cooked foods from the menu but also any prepared foods.
"They politely declined a salad", Wrangham writes in Catching Fire, "because its ingredients had been chopped and mixed. The natural way, they explained, is to do what chimpanzees do. Just as those apes find only one kind of fruit when eating in a given tree, so we should eat only one kind of food in any meal." Out came a basket prepared ahead of time by the trio and smuggled into the restaurant. One raw foodie chose an apple, another a pineapple; the third opted for chunks of buffalo femur, inside of which was "a cold pink mush that looked like strawberry ice cream". Raw, these foods "best suited" the diners' bodies - or so the diners' instincts informed them.
Wrangham fails to record what he himself ate at the lunch. We may guess that he accepted prepared, cooked items from the menu rather than dipping into the ape-dietoriented basket. And we may guess as well that he was too polite to announce a conclusion that would come to underpin Catching Fire: had his cooked-food-refusing companions lived in the Palaeolithic instead of the pampered present, their genes wouldn't have contributed much to the evolution of Homo sapiens.
According to Wrangham, cooking was the main reason that humans evolved differently from apes. "Cooking", Wrangham writes, "increased the value of our food. It changed our bodies, our brains, our use of time, and our social lives." This is no Man-the-Hunter theory with an added-value cooking clause, for it is plant matter and not meat on which Wrangham focuses. "Certainly meat eating has been an important factor in human evolution and nutrition", he notes, "but it has had less impact on our bodies than cooked food. Even vegetarians thrive on cooked diets. We are cooks more than carnivores." Jargon-free and jarring in the best way of offering new angles on old conundrums, Catching Fire is good public anthropology. With its balance of storytelling (that pink-gloop-filled buffalo femur grabs the reader in the first chapter) and coherently explained data, the book will enjoy a deservedly wide readership.
read more An apt question is whether "coherently explained" translates to "convincing". The biologist Steve Jones has complained that the book offers too many "empty calories", because Wrangham speculates so freely on our past. Yet four out of the book's five central arguments - the impact of cooking on our food, our bodies, our brains, our use of time, and our social lives - are substantive and convincing. The last of his arguments is the least persuasive. Despite his welcome abandonment of spear-thrusting male hunters as the drivers of humanity's development, Wrangham falls headlong into a genderessentializing trap. His argument about the evolution of our social lives is weakened as a result.
To take his theses in turn, beginning with food value: raw-food diets rage in popularity. Yet case study after case study offered by Wrangham, ranging from Inuit (Eskimo) traditional diets to the desperate choices of people lost at sea, show that raw foods can't properly sustain the human body for longer than about a month. Our species cannot do what other animals can: extract enough energy from non-cooked foods to survive on them in the long term. Here, Wrangham's case seems airtight. Cooking makes up for humans' physiological constraints - or brought them about in the first place? - because it "substantially increases the amount of energy we obtain from our food". Through cooking, starch is gelatinized, which means that enzymes make it more readily digestible. Further, protein is denatured, and foods are rendered softer, aiding in digestion as well. Gains to our ancestors' reproductive success must have been considerable, Wrangham reasons, in order to offset the nutrients that may be lost and the toxins that may creep in with cooking. "When our ancestors first obtained extra calories by cooking their food", he summarizes, "they and their descendants passed on more genes than others of their species who ate raw."
Who, then, were the first cooks? Pride of place is given to Homo erectus, upright walkers much resembling us in physical form. These ancestors originated a number of startling innovations in technology and colonized new areas of the globe. Wrangham's logic regarding this choice of ancestor is clean. As he outlines, meat-eating may explain the origins of our genus Homo, because com- pared to earlier forms like australopithecines, the first Homo species (called Homo habilis) was able to scavenge more meat, allowing a brain expansion. But the astounding brainand-behaviour flowering that came along with Homo erectus cannot be tied to meateating.
The jaws and teeth of Homo erectus are "poorly adapted for eating the tough raw meat of game animals", and "cannot be explained by Homo erectus's becoming better at hunting. Something else must have been going on". That something else, of course, was acquiring energy from cooked foods.
It is hard to date the advent of cooking precisely, although a site in Israel strongly suggests its origins at about 800,000 years ago. Comparative anatomy, once again, comes to the rescue. With Homo erectus, Wrangham writes, we see not only a tooth reduction, but also the winning combination of smaller gut and bigger brain. Both, he believes, were made possible by cooking - the smaller gut because of the changes in food value, the bigger brain because of the extra energy unleashed. In short, "cooking was responsible for the evolution of Homo erectus". A glance at the roster of behavioural firsts achieved by Homo erectus - first travel outside the African continent, first creation of a complex stone tool kit, and so on - fits comfortably with this conclusion. And this transformative process would have been ongoing. "Although the breakthrough of using fire at all would have been the biggest culinary leap", Wrangham notes, "the subsequent discovery of better ways to prepare the food would have led to continual increases in digestive efficiency, leaving more energy for brain growth."
Wrangham introduces at this stage of his argument a novel concept: the chewing time budget. Raw-food diets require lots of chewing.
Time and energy diverted to chewing aren't free for more calorie-enhancing pursuits.
Cooking, writes Wrangham, "freed hunters from previous time constraints by reducing the time spent chewing. .. . Hunting could contribute to the full development of the family household, reliant as it is on a predictable economic exchange between women and men". It is reasonable enough to invoke, as generations of anthropologists have done, a male-female division of labour in our evolutionary past. It's in the next bedevilling details where Wrangham makes a wrong turn. Wrangham contends that cooking is and always has been women's work: "Women's cooking for the family is a universal pattern", he flatly states. In a famous anthropological study of the 1970s, when 185 cultures were surveyed for sex differences in productive activities, cooking came in as the most female-biased. Women did all or most of the cooking in 97.8 per cent of the societies surveyed. Even the exceptions, Wrangham claims, work in his favour, because where men cook, they do so for the community instead of the family. This family-versus-community distinction matters for reasons we will see more clearly in a moment.
There is no use injecting gratuitous egalitarianism into cross-cultural data; if men aren't cooking, they aren't cooking. And there's really no doubt that women cook more than men do, around the world. Yet this separation of the sexes is neither as invariant as Wrangham would have us believe, nor as accurately projected back into our past. In The Hadza (published earlier this year), the anthropologist Frank Marlowe offers a fascinating ethnography of the Hadza people, hunter-gatherers of Tanzania. Wrangham himself refers briefly to the sexual division of labour among the Hadza, but Marlowe's rich data flesh out the picture. He lists five "common" scenarios regarding Hadza food-gathering. In one, women go out and dig tubers, then roast and eat them on the spot. In another, "a man returns to camp with a rock hyrax that he cooks for his children only". The point here is not that women don't cook for their families as much as Wrangham says, nor that men cook more for their families than Wrangham says. It's rather that an abundance of caution is needed when one projects a contemporary pattern of foraging millions of years into the past. Careful ethnographic analogy is, though, a staple of anthropology, and lots of data from hunter-gatherer societies do accord with Wrangham's framework. On balance, Wrangham gets a considered pass here.
Far more problematic is his insistence that prehistoric women cooks would have needed male protection. Wrangham's chain of inference begins like this: cooking takes effort and energy, and the hard-won products of cooking are ripe for stealing by shirkers in the community. How would our ancestors have responded to the threat of thieves in their midst? Pair bonds, asserts Wrangham, via a sort of "primitive protection racket". As he sees it, "husbands used their bonds with other men in the community to protect their wives from being robbed, and women returned the favour by preparing their husbands' meals. Females needed male protection, specifically because of cooking". So not only are women consigned to the prehistoric home and hearth, they must also be made weak and vulnerable. This smacks of outdated cultural norms, and alternative possibilities spring readily to mind. Why is a male tapped for the starring role of protector? Women were physically smaller and thus weaker on average, yes; the fossils tell us this. But what about women's alliances? Precedent for this sort of female bonding surely exists in the behaviour of some apes. Yet Wrangham dismisses the idea out of hand: "There are no indications that human females or their ancestors have ever been prone to forming the kinds of physical fighting alliances with one another that protect bonobo females from being bullied by males", he says. What indication, though, would he wish palaeoanthropologists to search for? Isn't this speculative arena - the nature of our ancestors' social lives far back in time - relatively evidence-free, beyond the fact of sex differences in size? And what if the highest goal achievable, as a result, is simply the internal coherence of a speculative argument? Keeping that goal in mind, isn't the logic (without direct evidence) of female-female alliances just as solid as the logic (without direct evidence) that early Homo erectus pair-bonded at all? Catching Fire, with its treasure trove of great stories, makes for pleasurable consumption. But its stories about our gendered past, prepared and served up with flair and confidence, require a keenly discerning palate. We may politely decline to believe some of them.