Kissing: More Socially Complex Than You Realize

You may live in a culture where a smooch is a natural part of expressing love, but thats not how it works everywhere. Mark Edward Atkinson/Tracey Lee/Getty Images

Kissing may seem like a universal way to give and receive affection and intimacy if you're American or European, but ask the Mehinaku tribe in Brazil, and they'll tell you that a penchant for puckering is gross.

As it turns out, estimates of the number of people who kiss romantically or sexually worldwide may be way off. In 2013, it was estimated that kissing is practiced among 90 percent of global cultures. But a new study published in a recent issue of American Anthropologist focusing only on romantic/sexual kissing between couples found that fewer than half of the 168 cultures studied engaged in romantic/sexual kissing. The study used data from the Electronic Human Relations Area Files (eHRAF), but went an additional step by surveying ethnographers to learn the more intimate details of the cultures.

Although it's not clear where in the world romantic kissing began, the earliest evidence of humans caught in the act is believed to be in Vedic Sanskrit writings more than 3,500 years old. Today it's most prevalent in the Middle East:

  • 10 out of 10 modern Middle Eastern cultures studied engaged in romantic kissing.
  • Seventy-three percent of Asian cultures studied kiss romantically.
  • Seventy percent of European cultures studied engage in romantic kissing.
  • Only 55 percent of the North American cultures studied kiss romantically.

Falling in love may feel like a uniquely personal and individual experience, but romantic love is actually shaped by broader social forces. Cultural consensus has the ability to constrain society's social behaviors, like who you fall in love with, and how you feel and act toward your significant other.

According to Dr. Justin Garcia, co-author of the study and a research scientist at The Kinsey Institute, "This is a real reminder of how Western ethnocentrism can bias the way we think about human behavior.” The researchers found that romantic kissing was most pervasive and accepted within socially complex cultures and societies with established social class systems. 

During the Roman Empire, for example, there were strictly defined class distinctions, from slaves to the emperor, and with them were also strict rules regarding who, and what body part, may or may not be kissed. But the romantic kiss faded away with the fall of the Roman Empire, and the practice wouldn't resurface again for more than 1,000 years, when romantic courtly love became fashionable in the 11th century. 

While romantic kissing can be part of modern sexual intimacy and trigger the release of oxytocin, nicknamed the love hormone because it makes us feel bonded and close to another person, other physical behaviors can do the same thing.

"The physical sensation of someone's tongue in your mouth is neither a unique trigger for sexual arousal nor a magic crystal ball for peering into someone's soul. But in American culture, we treat it as if it is," says Dr. Kimberly J. McGann, Associate Professor of Sociology at Nazareth College. "Given a different time, place, and set of social norms, people could just as easily be swooning for the best huggers, hand massagers, or hair brushers."

Garcia acknowledges that open-mouth kissing may be a way for us to determine compatibility — so-called chemistry — with another person. It's been theorized that the exchange of saliva during a prolonged kiss may help us evaluate a new mate, Fifty-nine percent of men and 66 percent of women say they end a new relationship because of a bad kiss. “There is likely a biological underpinning to kissing," he explains, "as it can often involve exchange of pheromones and saliva, and also pathogens."

But how a society changes from one that does not engage in romantic kissing to one that does, explains Garcia, is "still an open question for research."


Eighty million bacteria are exchanged during a 10-second open-mouth kiss.