It's a pretty common trope in sitcoms: man thinks something, man meets woman, man is unable to continue thinking. But, like all good comedy, the cliché has its roots in human nature. It, in fact, has roots in science as well. Researchers found that, for men, even the thought of interacting with a woman was enough to cause cognitive impairment.

In 2009, a study published in the Journal of Experimental Social Psychology found that, after interacting with an attractive woman for a short period of time, heterosexual men's cognitive ability declined. More recently, a team of Dutch researchers attempted to see if they could take that correlation one step further. They conducted two experiments using male and female college students.

Both tests started with the Stroop test. The test shows participants the name of a color, like "orange." The color is written in a different color, like blue. Participants need to quickly identify the color in which the word is written, rather than what the word is. The test is pretty difficult because participants naturally read the word, confusing their brains.

For the first study, participants were told that they were going to be performing a lip-reading task, and researchers told them that an observer would be watching, but not interacting, with them. The observer, who did not exist, was either given a typical male or female name. Then participants were again given the Stroop test. Women's performance on the Stroop test did not change, whether they thought that a man or woman was watching them. But men's performances suffered if they thought that a woman was watching them, even though they had not interacted with an observer.

The second study began with researchers telling participants that they would need to perform the same lip-reading task that was conducted in the first study. Half were told that a woman would observe them, and half were told that men would. In the end, they never performed the lip-reading task at all. Researchers gave the volunteers a second Stroop test to measure their cognitive ability. But they found that while women's performance remained steady, men's performance dropped if they were told that a woman would be watching them.

Researchers did not offer an explanation for why even the anticipation of interacting with a woman affected men's brainpower. They also do not know why cognitive impairment occurs even when "men have little to no opportunity to impress her and, moreover, have little to no information about the mate value of their interaction partner". But one theory suggests that men's thinking ability may be hampered because they are concerned about the impression that they are making.

The research was published in the Archives of Sexual Behavior.