At the start of the 20th Century, the people of the western world were becoming increasingly aware of what infectious diseases were and how they were spread. The public were understandably anxious about catching such an illness; among the top causes of death in 1900 were infections like influenza and tuberculosis. This anxiety led to some taking rather extreme measures to lower the risk of infection – including anti-kissing leagues.
Taken from a newspaper article from August 28th, 1905
If you can’t quite make out what the article says, it beautifully states that “members of the league take a solemn pledge not to kiss each other, in public or in private, their contention being that kissing is the means of conveying contagious diseases from one fair lip to another”. The Anti-Kissing Leagues of Paris and Vienna were totally against kissing in general and were seen as the most hardcore of all the anti-kissers, claiming “indiscriminate kissing is more dangerous than a motor smash”.
The French claimed that 40,000 germs were transferred in every kiss and so the solution seemed simple – tell people about this disgusting fact, and humanity shall smooch no more and we can wave goodbye to infectious disease. Believing that they had cottoned onto an idea stolen from the Japanese – all kissing scenes had to be cut from European and American films before they were shown in Japan – the French supposed that the reasoning behind this was because the Japanese did not wish to get ill and so would not promote such a vulgar practice as kissing.
But the Americans were having none of this anti-kissing nonsense, it would seem: They called on SCIENCE, and in 1927 a neat little experiment was published in the popular science magazine Science and Invention. Participants were invited to kiss a Petri dish containing a sterile culture medium. After their romantic encounter, the Petri dishes were incubated for 24 hours, allowing any germs that had been transferred from grotty human lips to the sterile culture to multiply into little visible colonies of bacteria. The scientists counted these bacteria, and concluded that far from the French estimate of 40,000, a mere 500 germs were transferred in a kiss – although women wearing lipstick passed on ~200 more.
So kissing does involve the transfer of bacteria, but not as much as we once thought. And if you really worry about these things, avoid kissing people who are wearing lipstick. But I think we should all say a big THANK YOU to science for allowing us to shneck, smooch and snog as much as we like.
I read about this experiment in The Mad Science Book by Reto U. Schneider which is awesome, you should check it out.