Wild chimpanzees have been found to naturally consume alcohol while feeding on ripe fruits, and new research suggests this behavior could explain the roots of human attraction to alcohol. Scientists discovered that chimps can ingest the equivalent of a small bottle of lager each day simply by eating fruits like figs and plums, which naturally ferment and produce ethanol.
How chimps consume alcohol
Researchers studied chimpanzees in Côte d’Ivoire and Uganda and measured the ethanol levels in the fruits they frequently eat. Based on their average intake, chimps were consuming around 14 grams of ethanol daily, which is close to two UK alcohol units or a 330ml lager. Interestingly, the chimps often preferred fruits with the highest alcohol content, showing a natural attraction to fermented foods.
The drunken monkey theory
This study supports the “drunken monkey hypothesis,” an idea proposed by experts that suggests humans inherited their liking for alcohol from primate ancestors who relied on fermented fruits for food millions of years ago. Researchers believe this evolutionary link dates back around 30 million years and may explain why humans developed such a strong cultural and social connection with alcohol.
Social and survival aspects
Experts also suggest that sharing fallen fruits may help chimps strengthen social bonds, as groups often gather to eat together. However, it is important to note that the alcohol levels consumed are not enough to make them drunk, which could otherwise reduce their survival chances in the wild.
Conservation concerns
While these findings highlight a fascinating link between humans and primates, chimpanzees remain an endangered species. Habitat destruction due to farming, logging, and infrastructure development continues to threaten their survival. Protecting their natural environment is crucial, not only for their future but also for understanding more about our own evolutionary history.



















