It turns out that wild monkeys prefer alcohol

It was confirmed that primates prefer to eat 'fruits rich in alcohol'. This observation may lead to an understanding of why humans prefer alcohol.

Dietary ethanol ingestion by free-ranging spider monkeys (Ateles geoffroyi) | Royal Society Open Science
https://doi.org/10.1098/rsos.211729

Monkeys often eat fruit containing alcohol, shedding light on our taste for booze | Berkeley News
https://news.berkeley.edu/2022/03/30/monkeys-routinely-eat-fruit-containing-alcohol-shedding-light-on-our-own-taste-for-booze/

Professor Robert Dudley of the University of California has discovered from past observations that 'some of the fruits that primates like to eat contain up to 7% ethanol when fermented.' In general, fermented fruits containing ethanol are known to be more nutritious than normal fruits, so Professor Dudley said, 'The tendency of humans to prefer alcohol is that primates of ancestors'fermented. I made the 'drunk monkey hypothesis' that it may be due to the fact that I liked to eat 'nutritious fruits'. However, at the time of making this hypothesis, there was no data that non-human primates 'preferentially eat fermented fruits' and 'can digest ethanol contained in fruits'.

So, a joint research team at the University of California and the State University of California collected and analyzed fruit debris eaten by wild black- handed spider monkeys on Barro Colorado Island in Panama to test the 'drunk monkey hypothesis.'

As a result, many of the fruits eaten by black-handed spider monkeys are the fruits of Spondias mombin , which has been used by people living in Central and South America for the production of the alcoholic beverage ' chicha ' for thousands of years. It turned out to have included.

Furthermore, as a result of analyzing the urine of the black-handed spider monkey, the components ' ethyl glucuronide ' and 'ethyl hydrogen sulfate ' generated during the metabolism of ethanol were detected. Based on these results, Professor Dudley said, 'The fruits eaten by black-handed spider monkeys contain ethanol, and black-handed spider monkeys can digest the ethanol.' It is appealing that it is approaching the proof of the 'hypothesis'.

'Because the black-handed spider monkeys get full before they get drunk, they won't get drunk,' said Professor Dudley. 'The reason why black-handed spider monkeys eat ethanol-rich fruits is that they get drunk by alcohol consumption.' He explains that it is not 'to enjoy the sensation' but 'to eat nutritious food'.