The New York Times says scientists at FSU conducted experiments in which they would observe young men assembling a Lego block puzzle with a 21-year-old woman.

But the real experiment came later, when each man rated her attractiveness. Previous research had shown that a woman at the fertile stage of her menstrual cycle seems more attractive, and that same effect was observed here — but only when this woman was rated by a man who wasn’t already involved with someone else.

The other guys, the ones in romantic relationships, rated her as significantly less attractive when she was at the peak stage of fertility, presumably because at some level they sensed she then posed the greatest threat to their long-term relationships. To avoid being enticed to stray, they apparently told themselves she wasn’t all that hot anyway.

Whenever I read the results of one of these scientific studies, I am alarmed to discover how much I am doing behind the scenes of my own consciousness, without my own implicit agreement.

(Thanks, Slog tipper Anna.)