“Drunk Monkey” Experiment May Explain Our Love For Alcohol

Does human affinity for alcohol stem from our primate roots?

Could be.

A study released last month in the British medical journal Royal Society Open Science, proposes that our love of alcohol started millions of years ago when our primate ancestors learned that the scent of alcohol meant ripe fruit. When fruit gets very ripe it ferments naturally and becomes alcoholic. The theory is called the “drunken monkey” hypothesis, according to EurekAlert.

“For the first time, we have been able to show, without a shadow of a doubt, that wild primates, with no human interference, consume fruit-containing ethanol,” Christina Campbell, one of the scientists in the study and a primatologist at California State University, told EurekAlert. “It looks like there may be some truth to that ‘drunken monkey’ hypothesis — that the proclivity of humans to consume alcohol stems from a deep-rooted affinity of frugivorous [fruit-eating] primates for naturally-occurring ethanol within ripe fruit.”

The study followed a group of free-range black-handed spider monkeys in Panama for four months in 2013. Primatologists examined the fruit that the monkeys were eating and found that it contained between one and two percent alcohol by volume (ABV) — about as much as a low-ABV cocktail. They then analyzed the urine of the monkeys and confirmed that it contained alcohol byproducts.

Researchers have been trying to prove that this hypothesis is true for decades, but this is one of the first studies to back it up.

So it turns out, we may like the taste of alcohol because our primate relatives evolved their senses in order to find the ripest fruit, which contains more calories than less-ripe fruit. For monkeys, it’s a matter of survival, not getting loaded.