(They found that straight glasses cause people to drink more slowly than curved ones. In a test people with straight glasses were 60% slower when consuming alcoholic beverages than those drinking from curved glasses. Markings on a glass also slowed the speed at which people drank. People with a marked glass took an average of 10.3 minutes to finish a pint, while the non-marked glass group took 9.1 minutes.
Unfortunately I think this means pubs and restaurants will soon be removing all markings and serving everything in curvy glasses.)