Don't hold a beer.

REUTERS/Michael Dalder

People often do idiotic things after they've had too many drinks.

No wonder that even holding a beer makes you look less intelligent, according to a joint study by the University of Michigan and University of Pennsylvania.

"People who hold an alcoholic beverage are perceived to be less intelligent than those who do not, a mistake we term the imbibing idiot bias," write authors Scott Rick and Maurice Schweitzer.