Have you ever noticed that the more people you go out drinking with the more drunk you get? This boozy breed of groupthink recently got empirical validation in the form of a new study by University of Cardiff researchers in the journal BMC Public Health. Team members went out on Friday and Saturday nights, between 8 p.m. and 3 a.m., stopping every seventh person they saw, and asking them to take a Breathalyzer test and answer a couple questions about how drunk they were, how extreme of a night they were having, and how much they thought booze would affect their long-term health. They ended up doing alcohol tests with 1,862 people, 400 of whom answered all the questions.
And as you may have inferred from every terrible night out you had in college, it wasn’t the absolute number of drinks that individuals had that predicted how drunk they thought they were, but rather how much their friends were or weren’t drinking. The research team, led by Cardiff public-health researcher Simon C. Moore, concluded that it was a matter of “rank”: If you had downed six beers through the night but had drunk the fifth-most among a crew of six revelers, you’d report being less drunk than if you’d drunk the same amount but been the heaviest drinker among your crew.
“Animals, ranging from crayfish to monkeys, are generally very sensitive to rank position within a hierarchy,” the researchers write. Indeed, the authors say, the rank-based reasoning may explain how entire cultures shift from drinking more to less, as Britain has, a couple times. “Such rank sensitivity may also explain why drinking increases in a society; if everyone drank another 10 units per week, no one would believe themselves to be more at risk of alcohol related disorder as their rank positions would remain the same, ” the authors write. This also explains why New York is so soaked in booze —nobody drives, everybody drinks — while a place like Los Angeles — everybody drives, everybody slugs wheatgrass — is so comparatively dry. If cultural norms say a behavior is normal, it is.