Alcohol use has a long and ubiquitous history. Despite considerable researchon the misuse of alcohol, no one has ever asked why it might have become universallyadopted, although the conventional view assumes that its only benefit is hedonic. Incontrast, we suggest that alcohol consumption was adopted because it has socialbenefits that relate both to health and social bonding. We combine data from a nationalsurvey with data from more detailed behavioural and observational studies to show thatsocial drinkers have more friends on whom they can depend for emotional and othersupport, and feel more engaged with, and trusting of, their local community. Alcohol isknown to trigger the endorphin system, and the social consumption of alcohol may thushave the same effect as the many other social activities such as laughter, singing anddancing that we use as a means of servicing and reinforcing social bonds.