01/29/2013 05:15 pm ET

Penicillin Started The Sexual Revolution, Not The Pill, Says Economist

"Sexy" likely isn't the first word that comes to mind when you think about penicillin. But according to economist Andrew Francis, perhaps it should be. He contends that it's the drug that launched the so-called "sexual revolution."

Conventional wisdom tells us that the birth control pill, which gained widespread use in the '60s and '70s and allowed women to have sex without worrying as much about unplanned pregnancy, was the spark for more lax attitudes about sex in general. However, Francis' research indicates that penicillin -- which rapidly decreased the rates of syphilis during the 1950s -- actually started the sexual revolution over a decade earlier. Once fear of contracting syphilis -- which Francis called "the the AIDS of the late 1930s and early 1940s" in a press release -- waned, young people embraced more nontraditional sexual behaviors because the cost of doing so was effectively reduced.

Francis, an economist at Emory University, analyzed data from the 1930s through the 1970s measuring three indicators of "risky" sexual behavior: the illegitimate birth ratio, teen birth rates and incidences of gonorrhea. He found that all three measures increased substantially by the late 1950s -- the same time that rates of syphilis bottomed out. (The incidence rate of the disease decreased by 95 percent between 1947 and 1957.)

"The 1950s are associated with prudish, more traditional sexual behaviors," Francis said in a press release. "That may have been true for many adults, but not necessarily for young adults. It's important to recognize how reducing the fear of syphilis affected sexual behaviors."

And since the birth control pill was only made legal to distribute to unmarried women in 1973, contraception can't explain this earlier change in sexual patterns. In his analysis, which appears in the January issue of Archives of Sexual Behavior, Francis argues that factors such as increased family planning were compatible with the sexual patterns that had already emerged as a result of penicillin use.

While a factor can't claim exclusive credit for pushing us into the era of casual sex, penicillin's virtual collapse of the syphilis epidemic likely played a large role. So next time you enjoy a guilt-free, syphilis-free casual tryst, you know what to thank.



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