Who needs fancy feathers when you’ve got muscles

Hot off the psychology presses: Men work out at gyms because women are sexually attracted to muscular men. That’s the conclusion, after a careful four-year study, of two UCLA researchers.

The finding, by PhD student David Frederick and associate professor Martie Haselton, stemmed in part from a study of 99 UCLA undergraduates of varying brawniness. As described in a news release about the paper (entitled “Lift more weights, find more mates”), the undergrads were photographed and then rated for muscularity on a 9-point scale, where nine was the most muscular and one was the least.

The men were also quizzed about their sexual histories — and the muscular ones, it transpired, were twice as likely as the less muscular to have had more than three sexual partners in their life.

Other studies by the UCLA duo (published together in the latest issue of the Personality and Social Psychology Bulletin) found that men who rated themselves as being above-average muscular also were more promiscuous and more likely to have had short-term flings, including ones with women who had boyfriends.

To evolutionary psychologists Frederick and Haselton, this all adds up to a pattern: Muscularity is a sexual attention-getter akin to that show-off peacock’s tail. But both peacock tail and muscles have their downside, and in the latter case, Frederick says, it’s that the muscle-building hormone testosterone is associated with suppression of the immune system.

Thus, Frederick says, muscles are “indicators of mate quality” because — like that preposterous tail — they “demonstrate an ability to flourish in the face of what’s really a drag on the system.”

“If you’re trying to figure out why men — especially young men — spend so much time at the gym, here’s your answer,” he said.

A postscript to the body builders: Women don’t seem to like extremes. When asked to rate six silhouettes of men with different degrees of brawn, women rated the in-between “toned” men as most sexually attractive — and also more sexually trustworthy.

— Rosie Mestel