Take a look at this Victorian illusion.
Most people think that the top hat is taller than it is wide.
In fact, the two distances are exactly the same, and the illusion is caused by people
perceiving horizontal lines as being shorter than vertical ones.
The same illusion makes people underestimate the width of short wide glasses, and so they
tend to pour more liquid into the glass.
In fact, research from Cornell University shows that people pour 30% more liquid into
short wide glasses than tall thin ones, and that even experienced bartenders pour 20%
more.
So, if you want to cut down on your drinking the easy way, go for tall thin glasses.