Once upon a time, young men and women couldn’t go about having sex all willy-nilly without worry, but then along came the Pill, divorcing us from our reproductive destinies and ushering in the sexual revolution—or so the story goes. A new economic analysis, however, shows how this legend may give birth control too much credit. A bigger factor in launching the modern sexual milieu may be the widespread use of penicillin for treating syphilis.
Under these new calculations, from Emory University economist Andrew Francis, the inciting incident of the free love era took place during the 1950s, almost a decade earlier than previously assumed. In an analysis published by the Archives of Sexual Behavior, Francis claims Americans really started having more casual sex as penicillin drove down its risks.
In the decades leading up to the 1950s, syphilis was a major killer in the United States (and a major deterrent to free love). In 1939 alone, it killed 20,000 people. ”It was the AIDS of the late 1930s and early 1940s,” said Francis. “Fear of catching syphilis and dying of it loomed large.”
Penicillin was discovered in 1928, but it wasn’t until World War II (when American GIs overseas started contracting sexually transmitted diseases) that the drug was found to fight syphilis. After the war, it became a staple in the general population, as well—transforming syphilis from a chronic, serious and possibly fatal disease to something that could be cured with a single dose of penicillin.
Between 1947 and 1957, syphilis rates dropped immensely. Deaths from syphilis fell by 75% and the syphilis incidence rate fell by 95%.
To test his penicillin/sexual revolution hypothesis, Francis looked at three measures of sexual behavior during that same time period: Illegitimate birth ratio, teen birth share and incidence of gonorrhea.
“As soon as syphilis bottoms out, in the mid- to late-1950s, you start to see dramatic increases in all three measures of risky sexual behavior,” he found.
Obviously many things contributed to changing sexual norms in the 1960s and 1970s; penicillin did it no more single-handedly than the Pill, or generational rebellion or any of the myriad things that propelled us from I Love Lucy to Teen Mom.
Still, penicillin has been a seriously overlooked factor in this equation, according to Francis. ”The 1950s are associated with prudish, more traditional sexual behaviors, (which) 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.”
“People don’t generally think of sexual behavior in economic terms,” he added, “but it’s important to do so because sexual behavior, just like other behaviors, responds to incentives.”