Judging Alcohol Intake More Difficult if You Drink From a Curved Glass

The shape of your glass may influence how much alcohol you consume, a new study suggests. Researchers in England found a curved glass interferes with a person’s ability to judge their alcohol intake.

“When drinking alcohol, most of us pace ourselves,” lead researcher Angela Attwood of the University of Bristol told NPR. “Because the feeling of drunkenness comes later, we rely on visual cues to tell us how much we’ve been drinking and when to slow down.” She noted those visual cues include the height of liquid remaining in the glass.

“For straight glasses, the halfway point in height is the same as the halfway point in volume, but when you’ve got a shaped glass it doesn’t work very well,” she said.

Study participants were asked to drink either a non-alcoholic soft drink or beer from one of two different types of glasses. One was straight, and the other was fluted—narrow at the bottom, and wide at the top. Participants drank beer almost twice as fast in the fluted glasses compared with the straight glasses, but people with non-alcoholic beverages drank them at the same rate, regardless of the shape of the glass.

One week later, participants looked at pictures of straight or curved glasses with varying levels of liquid, and were asked to decide if the glass was more or less than half full. Participants had a much more difficult time finding the halfway point of the curved glass than the straight glass. Those who were worst at judging the halfway point were the same people who drank their beer the fastest in the earlier experiment.

“People often talk of ‘pacing themselves’ when drinking alcohol as a means of controlling levels of drunkenness, and I think the important point to take from our research is that the ability to pace effectively may be compromised when drinking from certain types of glasses,” Dr. Attwood said in a news release.

The findings appear in the journal PLoS ONE.