A few years back, a study found that men did worse on tests when there was a woman in the room.  The conclusion was that the mere presence of a woman makes men dumber.

Now, the same researchers have taken it even further.  It doesn't take a woman in the room to make men stupid, nope - all it takes is the idea of talking to a woman to make men stupid.

For the follow-up study, the men took another test:  This time, they were told that a man or woman would send them a few instant messages during the test.

The instant messages never came.  But the guys who thought they were getting messages from a woman did worse on the test than the guys who thought they were getting the messages from another man.

So, just thinking a woman was going to talk to them made these guys dumber.

The researchers think it happens because men are socialized to think they have to be funny and charming around women, and that can get in the way of normal brain function.

And what better way to illustrate this than with a couple of classic clips from the movie 'Dumb and Dumber':