Monkeys cook?

Findings published in the journal, Proceedings of the Royal Society B suggest that chimpanzees’ minds are capable of cooking. Though they may lack humans’ knowledge of fire, scientists believe that chimpanzees do possess most of the intellectual abilities required to cook food.

A recent, in-depth study found that chimpanzees not only prefer the taste of cooked food but they can hold up eating while waiting for it – and even choose to store raw vegetables if they are aware of any chance to cook them later on. These findings suggest that ancient people may have developed a taste for roast vegetables and grilled meat earlier than had been previously thought. This potentially moves the timeline for one of the critical transitions in human history.

Humans’ transition to cooked food is widely deemed as a critical evolutionary milestone because it would have allowed our primitive ancestors to reduce the time spent on foraging, and chewing raw food while expanding their diets to extract far more calories. The process gave them more time for technological development which enabled larger populations to flourish.

Earlier, various animals have been shown to prefer cooked vegetables and meats since they are softer and easier to digest. But the range of intellectual abilities required to make the leap to actually preparing cooked food had largely been considered to be restricted to humans.

“What’s particularly interesting about cooking is it’s something we all do, but it involves a number of capacities that, even without the context of cooking, are thought to be uniquely human,” said Harvard University’s Dr Felix Warneken, an authority on the subject of chimpanzees.

This was investigated in a series of experiments at the Jane Goodall Institute’s Tchimpounga Chimpanzee Sanctuary in the Democratic Republic of Congo, where chimpanzees born wild were given the opportunity to prepare food using a “cooking device”. To ensure safety, this was actually a plastic lunchbox having a false bottom, which researchers used to “transform” raw sweet potato placed inside by the chimpanzees into a cooked slice of a similar size.

Warneken explains: “Originally we thought of setting up a camping cooker in their sleeping area, but you could imagine them getting hold of a gas tank or burning themselves. This was not a viable option.”

It was found that the chimps, given a straight choice, preferred to cook potato almost 90 per cent of the time and they were nearly as keen when they had to wait one minute while it was “cooked” by the researcher (who shook the plastic box 10 times).
The apes carried on opting for the cooked option 60 per cent of the time when they had to carry the food some distance in order to place it in the “oven” – even though this became a challenge since they often carried it in their mouths and they even seemed to eat the food on the way, “almost by accident”.

In a final display of self-control, around half the chimps chose to hoard raw potato – by setting aside up to 28 slices – when they knew they would be presented with the option of cooking it later on.

As Warneken commented: “Delayed gratification is a problem for us as well. We also have a tendency to nibble at food before we’ve finished cooking. Usually chimpanzees just eat what they can get right away and would never give up edible food, so it was remarkable to see that.”