Dr. Angela Attwood and colleagues from Bristol's School of Experimental Psychology recruited 160 social drinkers ages 18-40 with no history of alcoholism to attend two experimental sessions.
At one session the study participants were asked to drink either lager or a non-alcoholic soft drink from either a straight-sided glass or a curved "beer flute."
The study, published in the journal PLoS ONE, found those who drank alcohol were almost twice as slow when drinking alcohol from the straight-sided glass compared to the curved glass, but there was no difference in drinking rates from the glasses when the drink was non-alcoholic.
The researchers suggested the reason for this might be because it is more difficult to accurately judge the halfway point of shaped glasses; therefore, drinkers were less able to gauge how much they have consumed.
To test this hypothesis, the researchers had the participants attended another session in which they completed a computer task that presented numerous pictures of the two glasses containing varying volumes of liquid.
The researchers found there was greater error in accurately judging the halfway point of the curved glass.