Earlier this week, Ethan Trex taught us the history of shaving. Several readers left comments inquiring about when women started shaving their legs and underarms, so we cracked open the mental_floss book In the Beginning: The Origins of Everything. Here's what we learned:

Underarms

American women had no need to shave their underarms before about 1915 "“ after all, who ever saw them? Even the word "underarm" was considered scandalous, what with it being so near certain other interesting body parts. Then came the sleeveless dress. An ad in the fashion mag Harper's Bazaar decreed that to wear it (and certainly to wear it while participating in "Modern Dancing"), women would need to first see to "the removal of objectionable hair." They didn't need much convincing, and by the early '20s, hairy underarms were so last decade, at least in America.

Legs

The '20s fashion was risqué on the bottom half, too, but most women of the era didn't seem to feel the need to shave their legs, and when hemlines dropped again in the '30s, the point became moot. The '40s, however, brought even shorter skirts, sheerer stockings, and the rise of leggy pin-ups such as Betty Grable. "The removal of objectionable hair" suddenly applied to a lot more surface area.

Naughty Bits

Was it porn actresses who started this one? GIs concerned about disease? The Brazilians? Nah. For hundreds of years, the bikini wax has been a common practice among a group more often associated with extreme modesty: Muslim women. In much of the Middle East and North Africa, brides-to-be remove all their body hair before the wedding night. Yes, all of it. Frequently, they stick with the aesthetic after marriage "“ and some men do likewise.

You can pick up a copy of 'In the Beginning' in the mental_floss store.