Cape Town - Is the glass half full or half empty? Well… according to scientists, it depends on the shape of your glass.

In two experimental sessions, scientists from the University of Bristol tested the effect of different shaped glasses on drinking rate.

They tested 160 social drinkers aged 18-40 with no history of alcoholism. The participants were asked to drink either a lager or a non-alcoholic soft drink from either a straight-sided glass or a curved beer flute. They found that “participants were almost twice as slow when drinking alcohol from the straight-sided glass compared to the curved glass”. The same was found when the drink was non-alcoholic.

The research team, led by Angela Attwood of the School of Experimental Psychology, hypothesised that the curved shape of the glass made it difficult for people to accurately judge where the halfway point was. As a result, they were less able to realise how much they had drunk.

To test the hypothesis, participants attended another session where they completed a computer task looking at various pictures of the two glasses containing different volumes of liquid. They had to judge how full or empty the glasses were. By doing this, the researchers were able to show that it was more difficult to accurately judge the halfway point of the curved glass.

Attwood said while many people drank alcohol responsibly, it was not difficult to have “one too many”. She said the negative effects of alcohol on decision-making opened people up to a number of risks.

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