Why humans love alcohol

Alcohol has an unusually mixed reputation: you either love it, or you hate it. Excess consumption has obvious harmful consequences, not just for our cognitive and social competences in the immediate aftermath but also for our health in the longer term. Yet since the dawn of time, humans have persisted in its consumption, especially in social contexts. Indeed, in most cultures, feasts would be unthinkable if not accompanied by some form of alcohol.

The making of alcohol

The forms of grain like einkorn that were cultivated by the earliest farmers in the Middle East lacked the gluten that makes good bread, but would have made an excellent gruel for fermentation. Vats and vessels, some of quite enormous size, containing the residues of brewing have been discovered at several archaeological sites associated with the earliest settlements, some 8000 or so years ago. This was not just the making of beer for the family dinner: it was beer-making on an industrial scale for large feasts.

Why should we find alcohol so pleasurable?

One explanation, of course, is that alcohol relaxes us and makes us more confident in social circles. We enjoy the heady sensation and keep coming back for more. It makes the party go round.  Another is that we share with the other African great apes an enzyme that allows us to break down the alcohols in over-ripe fruit, to access the sugars they contain. So much so, in fact, that chimpanzees in West Africa raid the palm juice left out by farmers to ferment naturally into toddy, sometimes drinking litres at a time. It is a way of getting more out of what you eat. But there is more to alcohol than just hedonic pleasures and nutrients. The clue lies in the fact that we make such extensive use of it in social contexts. The key to this is that alcohol triggers the brain’s endorphin system. Endorphins are opioid neurotransmitters that form part of the brain’s pain management system. Indeed, weight for weight, endorphins are 30 times more effective as analgesics than morphine. Their significance in this context is that early in monkey and ape evolution, endorphins were co-opted to become the glue that holds our social world together.

A central role in communal bonding

The social importance of this in the context of modern life emerged from some large stratified national surveys. One showed that people who had a regular ‘local’ they attended had more close friends, felt happier and more contented with life, more trusting of their wider community and more engaged with the community than either non-drinkers or those who did not have a regular ‘local’. Correlations don't give us causes of course, but more detailed statistical analysis did suggest that these were the downstream benefits of social drinking rather than its cause. The same was true of social feasting, especially when alcohol was consumed. Of course, alcohol is not the only mechanism that gets us friends; nor is it free of negative consequences, especially for excess consumers. But it does seem to have played a central role in communal bonding since the dawn of history.

Robin Dunbar FBA is Emeritus Professor of Evolutionary Psychology at the University of Oxford. Kim Hockings is Lecturer in Biosciences at the University of Exeter. The British Academy conference Alcohol and Humans – A Long and Social Affair was held at the Academy from 13-14 September 2018.