Tentative evidence for 'drunken monkey hypothesis'

Before you started your break, you regularly drank an alcoholic drink. Why? Because you like it. Because it helps you relax. Because you just loosen up a bit with a few drinks. The reasons are various and all known. Our predilection for alcohol, and what it does to us, may be traced back to the primates. You can read more about the 'drunken monkey hypothesis' here.

Enjoying alcohol is something we have been doing for years. The oldest brewery recipe is about 5000 years old. But the foundation for our craving and craving for alcohol may have been laid millions of years ago. At least that's what biologist Robert Dudley claims. In 2014 he wrote a book 'The Drunken Monkey / Why We Drink and Abuse Alcohol' in which he laid out his theory. And now, indeed, researchers seem to have found tentative evidence to support this so-called 'drunken monkey' hypothesis.

What is the 'drunken monkey hypothesis'?

To explain the weakness for alcohol, we have to go back millions of years. A time when our ape-like ancestors discovered the scent of ripe, fermenting and nourishing fruit. Fruit that naturally has a high alcohol content, up to 7 percent. There seems to be tentative evidence that wild monkeys then and now consciously choose fruit with ethanol.

Taste the sum

Robert Dudley's theory was tested on a group of wild Geoffroy's spider monkeys living on Barro Colorado Island in Panama. Researchers collected discarded fruit scraps from this group of monkeys and analyzed their urine. What turned out? The researchers discovered that the alcohol concentration in the fruits was actually always between one and two percent – caused by the fermentation of sugar into alcohol by yeast. Moreover, the ripe fruit the monkeys collected came from the yellow mombin plum; a fruit that has been used for thousands of years by indigenous human populations in Central and South America to make chicha; a fermented alcoholic drink.

Tasty but especially high in calories

The urinalysis of the black-handed spider monkeys has shown that secondary metabolites of alcohol can be found. In other words, the monkeys don't just eat the fruit because it tastes good, they also eat the ethanol-containing fruit for the calories. Because more calories means more energy. So our penchant for alcohol may well stem from the weakness of fruit-eating primates for naturally occurring ethanol in ripe fruit.

Back to humans

Our ape-like ancestors ate the ethanol-containing fruit just for energy. We humans prefer to ignore the filling pulp of fermented fruit and drink alcohol in a liquid form. As a result, we often drink too much of it. Who is the smarter of the two here?… Source: scientas.nl