The Ancient Origins of Kissing

It’s the pinnacle of almost every Disney film. Eyes close, lips pout and faces draw near in preparation for true love’s first kiss. The simple graze of the lips plays an outsized role in contemporary society as the ultimate romantic symbol. But evolutionary biologists, historians and anthropologists are scratching their heads over why and how long we’ve been smacking our lips together.

Chimpanzees kiss, bonobos kiss, maybe even Neanderthals kissed. Viewed through an evolutionary biology lens, there are a couple of explanations for how kissing first evolved. It’s possible it arose from behaviors associated with affection, such as grooming with the mouth. Many apes also premasticate their food and transfer it to their young orally, so young apes might develop an affinity for mouth-to-mouth touch. Scientists also theorize that when couples graze lips, perhaps even exchange saliva, they get the opportunity to unconsciously swap olfactory cues about each other's fitness or compatibility.

While many animals make mouth-to-mouth contact, this behavior may not be for the same romantic or affectionate reasons as humans. To study the broader evolutionary history of kissing in all its forms, scientists had to create a robust definition of the act: non-aggressive touching of the mouth, with some lip movement and no food transfer. A 2026 study estimates kissing in the great apes evolved from a common ancestor around 21.5 million years ago, but the reasons why smooching evolved remain a conundrum.

Anthropologists broadly categorize human kissing into two categories: romantic-sexual and familial-friendly, platonic gestures that can show respect, trust or affection. While familial-friendly kissing is observed across different cultures and most primates, romantic-sexual kissing is less universal.

Until 2023, scholars cited the first record of sexual-romantic kissing in Vedic Sanskrit texts from around 1500 B.C. By looking at the spread of oral herpes, researchers then suggested that osculation—the scientific term for kissing—could have passed from South Asia to Europe during the Bronze Age, possibly with Alexander the Great’s conquest in the third century B.C.

But when he encountered the literature, Troels Arbøll—an Assyriologist at the University of Copenhagen specializing in the languages, history and cultures of ancient Mesopotamia—was left perplexed. “I knew in my field of Assyrology we have source material that mentions kissing that is older than this,” he says. To set the record straight, Arbøll and his co-author compiled other evidence of ancient romantic kissing across different cultures in the Middle East.

The oldest hints of kissing can be found in neolithic figurines from Israel and Malta, writes Arbøll, dating to around 9000 B.C. and 5500 B.C., respectively. The clay models appear to embrace with their faces smushed together, but it is debatable if the figures are actually kissing.

Firmer written evidence of the romantic gesture can be found in an ancient Sumerian manuscript dating to about 2600 B.C. The text recounts how Ezinan, a goddess of wheat, has intercourse with the god An, after which they share a kiss. She then gives birth to seven children. Many of the earliest Sumerian descriptions of kissing involve a post-coital buss shared among gods.

Through language analysis, Arbøll also found mention of kissing in ancient Egyptian, Akkadian and Eblaite languages related to Arabic and Hebrew. Contrary to the idea that kissing may have been spread from South Asia to Europe, Arbøll's findings show that kissing existed independently across different civilizations.

Despite its ancient origins, romantic-sexual kissing is not universal. A 2015 study looking at 168 cultures around the world found that romantic-sexual kissing was only found in 46 percent of societies. “You wouldn’t believe it, it [kissing] seems so natural,” says William Jankowiak, an anthropologist at the University of Nevada who was surprised by his own finding. Jankowiak says that some cultures, such as the Thonga from South East Africa and the Mehianku from the Amazon, found making out unappealing. “The Mehinaku, an Amazonian horticultural society, bite each other's eyebrows, but wouldn’t kiss,” he says.

After surveying ethnographers around the world, Jankowiak found that kissing was more common in stratified societies—those with distinct classes—than in more egalitarian groups such as hunter-gatherers. “What you find in the world of pleasure of the elite is a slow tease,” he says. Kissing as an act of delayed gratification could have become popular in the upper classes and spread to the masses.

Among egalitarian societies, ones in polar regions were more likely to kiss romantically than those in the tropics, notes Jankowiak. “In the tropics, clothing is minimal and you can have a sensual experience with many parts of the body,” he says, whereas in polar regions, contact is limited to the face.

Jankowiak doesn’t buy into the idea that kissing is an adaptation for exchanging scent cues—if that's true, why would half of human cultures not engage in it? Rather, he thinks kissing plays a role in experiencing sensuality and intimacy—human universals. That feeling of intimacy can be expressed through a passionate snog, but also through nibbling eyebrows like the Mehinaku or pressing faces and exchanging breath like with the Māori of New Zealand.