Short, wide glasses tend to be filled with more liquor than tall, narrow glasses.
In a Cornell University study outlined in the British Medical Journal, students poured 30% more into the short glasses, and bartenders increased the amounts by 20%.
Lead researcher Brian Wansink says the findings suggest that people should think more carefully about the amounts of liquor they drink.
"The way to better control alcohol consumption is to use tall glasses or to use glasses with the alcohol level marked on them."
