Ett samband mellan utvecklingen av våra stora hjärnor och tillagad mat? Ja det verkar finnas flera saker som tyder på det, både i våra kroppar, gener och närmaste släktingar.

All known human societies eat cooked foods, and biologists generally agree cooking could have had major effects on how the human body evolved. For example, cooked foods tend to be softer than raw ones, so humans can eat them with smaller teeth and weaker jaws. Cooking also increases the energy they can get from the food they eat. Starchy potatoes and other tubers, eaten by people across the world, are barely digestible when raw. Moreover, when humans try to eat more like chimpanzees and other primates, we cannot extract enough calories to live healthily. Up to 50 percent of women who exclusively eat raw foods develop amenorrhea, or lack of menstruation, a sign the body does not have enough energy to support a pregnancy—a big problem from an evolutionary perspective.

What is the connection between cooking and brains? Understanding how and why our brains got so big has been a major puzzle because such a brain is metabolically expensive. In fact, the brain needs more energy for its size than any other organ. Although it might seem being smarter is always better, having a big brain exerts a high toll. Ancestral humans may have compensated for this energy cost by cooking food.

Fossils show the teeth and digestive tract of Homo erectus decreased in size around the same time brain size increased. This evidence likely means our ancestors started eating softer, higher-quality foods (although not necessarily cooked). New archaeological research has also continued to push back the earliest known date for the control of fire. For example, traces of purposeful fire at Wonderwerk Cave in South Africa have been dated at more than a million years old. Recent studies further suggest humans have genetic adaptions for eating cooked foods—some of which are old, at least predating our split from Neandertals. Finally, some of my own work, with psychologist Felix Warneken, has shown chimpanzees possess many of the foundational cognitive capacities needed to start cooking—such as a preference for cooked food, patience to wait for foods to be cooked and the capacity to plan for and transport foods to a cooking site. These data mean ancestral humans likely shared the same abilities, and could have started cooking rapidly after gaining the ability to control fire.