According to a new study conducted in the UK, an optical illusion caused by curved drinking glasses can speed up the rate at which people drink alcohol.
Angela Attwood, an experimental psychologist at the University of Bristol, explains that people don’t always realize how much or how fast they’re drinking. She suspects that the shape of beer glasses might distort a person’s perception of how much alcohol is being consumed.
Atwood’s team conducted a study with 160 people divided into eight groups, all consisting of young, healthy people who were considered social drinkers and not alcoholics. The team found that one group consistently drank much faster than the others, the group drinking a full glass of beer out of curved glasses rather than straight ones. The group with straight glasses finished 354 mL of beer in about 13 minutes, whereas the group with curved glasses finished the same volume in less than eight minutes.
So why the increase in drinking speed? Atwood believes the difference is because the halfway point in a curved glass is not clear. Social beer drinkers tend to pace themselves when drinking alcohol, judging themselves by how fast they reach their halfway point. “A simple solution to this problem would be to mark beer glasses with the accurate halfway point,” says Atwood.
According to the World Health Organization (WHO), the harmful use of alcohol — defined as drinking that damages health and has negative social repercussions — results in 2.5 million deaths per year worldwide, and is the third largest factor in the global burden of disease.
Legislative solutions to curb binge drinking are so unpopular that many governments are reluctant to implement them, and Attwood and her colleagues instead hope to find a solution through education.