How much wine you drink depends on the type of glass you use.
Researchers at Cornell University had volunteers pour themselves a normal glass of wine.
They found when they were given a wide glass, they poured twelve percent more wine.
They also poured more wine when holding the glass, instead of placing it on the table.
And -- volunteers measured more white wine when using a clear glass -- suggesting the contrast of white wine against the glass can throw off your judgment.
Researchers say this is significant because people may think they are having one serving of wine -- when they are actually having two or three.