With the help of 160 lucky social drinkers aged 18 to 40 with no history of alcoholism, a study out of the University of Bristol has determined that glass shape has a big effect on alcoholic consumption rate. The studied drinkers finished their beverages twice as fast out of curved glasses as they did out of straight glasses. They were also shown numerous pictures of both types of glasses and asked whether each one was half-empty or half-full; as it turns out, the volume of liquid in curved glasses is harder to gauge visually, so it’s harder to tell how much you’ve imbibed.