How much you drink may depend on people on around you

People's decisions on whether or not to drink more alcohol is influenced by other drinkers and the environment around them, a new study has found.
While drinking, judgement of one's own levels of intoxication are linked to the drunkenness of their peers, and not on the objective amount of alcohol they have actually consumed, according to researchers from Cardiff University in the UK.
People's perception of their own drunkenness, the excess of their drinking and the long-term health implications of their drinking behaviour were related to how their own drunkenness ranked in comparison to others around them.
People were more likely to underestimate their own level of drinking, drunkenness and the associated risks when surrounded by others who were intoxicated but felt more at risk when surrounded by people who were more sober.

"This has very important implications for how we might work to reduce excessive alcohol consumption," said Professor Simon Moore from Cardiff University.
"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 greatest impact," added Moore.

Researchers tested the breath alcohol concentration (BrAC) of 1,862 individuals, selected from different social groups, who were on average 27 years old.
Alcometer tests were conducted between 8 pm and 3 am on Friday and Saturday evenings in four locations near large numbers of premises that served and sold alcohol.

Gender and location information were used to divide participants into eight reference groups - one group for each gender in each location, based on the assumption that drinkers would compare themselves to others of the same gender in the same location.
Individual BrAC levels were ranked within each reference group.
To study the relationship between rank and people's judgements, a sub-set of 400 participants answered four additional rank-based questions about how they perceived their level of drunkenness and the potential health consequences of their drinking.
Respondents with a BrAC of zero were not included in the rank-judgement analyses.
On average, people perceived themselves as moderately drunk and moderately at risk, although their BrAC exceeded standard US and UK drink driving limits (35 microgrammes of alcohol in 100 millilitres of breath).

Men on average had higher BrAC levels than women.
The study appears in the journal BMC Public Health.