Regardless of how much alcohol someone has consumed, if they observe others to be more drunk, they feel less at risk from drinking more.
Almost 90 percent of American adults drink alcohol at some point in their lifetime, and more than half of all alcohol consumed is in the form of binge drinking.
According to the 2016-2020 Dietary Guidelines for Americans, if alcohol is ingested at all, it should be in moderation, which equates to up to one drink per day for women and up to two drinks per day for men. However, 1 in 6 adults binge drink around four times per month, consuming an average of eight drinks per binge.
Alcohol slows the function of the central nervous system and alters a person's perception, emotion, movement, vision, and hearing. As a person becomes more intoxicated by alcohol, the changes caused in the brain become greater.
New research - published in the journal BMC Public Health - indicates that when people are drunk in a bar and surrounded by others who are also drinking alcohol, their judgment of their own drunkenness and the long-term health implications of heavy drinking is measured against how drunk they rate those people around them.
People drink more alcohol when surrounded by other drinkers
Individuals are more likely to underestimate their own level of drinking, drunkenness, and the associated health risks when surrounded by others who are intoxicated. However, people feel more at risk of health implications and are more aware of their own level of intoxication when in the presence of sober people, the study says.
This study is the first research to examine how people judge their own drunkenness and health consequences of their drinking while intoxicated in real-world drinking environments. Previous studies have analyzed participants while sober and in non-drinking settings, which relies on a person recalling memories from the night, day, or week before to answer researchers' questions.
Asking participants questions while they are intoxicated and in a drinking environment can help with accuracy in their answers of comparisons between themselves and of others who are drinking. It was also previously unclear whether individuals compared their own intoxication levels to how intoxicated others were or how drunk they believed them to be.
"Researchers have historically worked under the assumption that those who drink most alcohol incorrectly 'imagine' everyone else also drinks to excess," says Prof. Simon Moore, the corresponding author from Cardiff University. "It turns out that irrespective of how much someone has drunk, if they observe others who are more drunk than they are, they feel less at risk from drinking more," he adds.
Breath alcohol concentration (BrAC) was tested in 1,862 individuals from different social groups between 8pm-3am on Friday and Saturday nights in four locations near large drinking establishments. Participants were divided into eight reference groups for each gender in each location, based on the assumption that people compare themselves to others of the same sex.
Researchers investigated the relationship between rank and people's judgment by asking 400 of the participants four additional rank-based questions to identify how they perceived their level of drunkenness and the potential health risks of their drinking.
They asked: "How drunk are you right now?" "How extreme has your drinking been tonight?" "If you drank as much as you have tonight every week how likely is it that you will damage your health and get liver cirrhosis in the next 15 years?"
People mostly perceived themselves as being moderately drunk and at moderate risk, even though their BrAC level exceeded U.S. driving limits. On average, men had higher BrAC levels than women.
Increasing numbers of sober people could decrease alcohol consumption
This insight into how people rank themselves against others in drinking environments could assist with strategies to reduce excess drinking. However, factors that influence drinkers' choices to drink more or less are complex, and only a few may lend themselves to intervention.
"This has very important implications for how we might work to reduce excessive alcohol consumption," says Moore.
Current evidence-based interventions to prevent binge drinking and the related harms involve increasing costs and excise taxes on alcoholic beverages, limiting the number of alcohol retail outlets that sell alcoholic beverages in a given area, placing time restrictions on alcohol access by restricting the hours of alcohol retail sales, and screening and counseling for alcohol misuse.
Moore and colleagues propose another method of intervention from the findings of the study, which could enable drinkers to use their judgment in comparing themselves to others to limit their alcohol intake.
"We could either work to reduce the number of very drunk people in a drinking environment, or we could increase the number of people who are sober. Our theory predicts the latter approach would have the greatest impact."
Prof. Simon Moore
While most participants influenced by others in the drinking environments were unlikely to know each other socially across the eight groups, the researchers suggest that further investigation is needed to assess the influences of more immediate social groups of friends on drinking perception.