AMERICAN women didn’t shave their armpits en masse until the 1920s, after a perfect storm of sleeveless dresses and a barrage of advertisements by depilatory makers characterized underarm hair as ugly.

Next came the tarnishing of women’s leg hair. By the 1930s, beauty writers scolded women with forests under their silk stockings. Decades later, what began as a fad had solidified into custom. Girls coming of age no longer needed to be told their leg hair was unsightly. They got rid of it.

Can the same thing happen with men?

These days, the hair on men’s chests, backs, armpits and even “down there” has become suspect  if you believe the marketing campaigns. Several recent online videos created by brands like Gillette recast hair removal below the neck as the domain of average Joes.

Having a chest as smooth as Matthew McConaughey’s is old hat for competitive swimmers, urbane insiders who became swept up in the metrosexual moment and some gay men who have long embraced hairlessness. To play Brüno, a gay fashion reporter who favors hot pants, the formerly hirsute Sacha Baron Cohen endured repeated waxathons to get bare nearly everywhere. But now evidence from market research and academia indicates that more men are removing hair from their chests, armpits and groins. The phenomenon skews to mostly college-age guys or those in their 30s. Reasons run the gamut from Because My Girlfriend Likes It to a desire to flaunt a six-pack or be clean.