The Oldest Recorded Kiss Happened 4,500 Years Ago, Scientists Say

Experiencing your “first kiss” is a rite of passage that has been dramatized countless times in pop culture. But what about humanity’s first kiss? When and why did our species start to express love and sexual desire by smooching up a storm? 

Solving this mystery could not only reveal insights about a cherished and widespread practice, it could also shed light on the epidemiology of diseases that are transmitted through mouth-to-mouth contact, such as the herpes simplex virus.

Now, a pair of scientists have traced the first written records of romantic kissing back some 4,500 years to ancient Mesopotamia, about 1,000 years earlier than previous work that linked the dawn of sexy smooches to Indian texts written in 1500 BCE.

Mesopotamian writers referred to kissing as an erotic act on clay tablets, producing “a substantial corpus of overlooked evidence” concerning the deep historical roots of kissing, according to a new article in the journal Science. 

“The earliest sources [that mention kissing] from 2500 BCE are in the Sumerian language (a language isolate), whereas some of the later sources from more private documentation are in the Akkadian language (a semitic language),” said Troels Pank Arbøll, an Assyriologist at the University of Oxford, in an email to Motherboard. 

“Writing in ancient Iraq was first used for administration when it was invented, which means that other genres of texts only gradually appear,” added Arbøll. “The first references to kissing occur in mythological narratives concerning the behavior and actions of gods. It is only a bit later (especially in the beginning of the 2nd millennium BCE) that we find clear references to kissing in private documents.” 

Arbøll and Sophie Lund Rasmussen, a biologist at the University of Oxford who co-authored the new article, were inspired to revisit the timeline of kissing after reading a study published in 2022 that suggested that romantic kissing in ancient societies could be connected to the spread of certain strains of the herpes simplex 1 virus, which is transmitted through oral contact.  

“We both found this a fascinating point of entry into a discussion of the first evidence for this type of kissing, and we quickly realized that most studies in the wider scientific community cited a source from India dated to ca. 1500 BCE as the earliest reference to romantic-sexual kissing,” Arbøll said. “I knew there was earlier material from ancient Mesopotamia, and when I started reading up on the subject I quickly realized that the evidence had been largely collected in a summary already in the 1980s, but apparently the information was never adopted in other fields, and it was therefore unknown in the larger scientific discourse on kissing.” 

“We therefore thought it would be a welcoming opportunity to write the perspective to make people aware of the existence of this old evidence, while we could at the same time highlight some current debates regarding the spread of this type of kissing and its effect on disease transmission in ancient history, as well as give our scientific take on these debates,” he added.

Kissing is undoubtedly one of the most hallowed and versatile rituals of our time. A kiss at the altar can ceremonially seal a marriage, and the “true love’s kiss” in fairy tales is a supernatural force. Beyond these romantic contexts, people kiss platonically to greet friends and express affection to loved ones. Kisses can even be gesturally performed with no contact, as is the case with “blowing kisses” or the classic “chef’s kiss.”

Friendly and parental kissing appears to be a practically universal practice throughout human history, but pinning down the origin of romantic kissing, specifically, is a trickier challenge. While some prehistoric sculptures may depict kissing, it’s difficult to distinguish between platonic and sexual kissing without explicit context.    

Arbøll and Rasmussen argued that the Mesopotamian references to kissing—in both romantic and friendly contexts—reveal that this practice was not an isolated invention, but rather emerged within a wide range of cultures during multiple eras that may extend deep into prehistory. Indeed, past studies have even speculated that early humans and our extinct relatives, Neanderthals, kissed more than 100,000 years ago.

“We argued in the article that this form of kissing was attested in a wide geographical area in ancient times, which included India and Mesopotamia, and the evidence does not point to a single point of origin, at least in historic times,” Arbøll said. “If someone insists one such should be found, it would have to be identified far back into prehistoric times.”

The independent rise of kissing across many times and cultures hints at a common purpose for this behavior. Intriguingly, chimpanzees and bonobos, which are now our closest living relatives, also kiss each other, though only bonobos perform mouth-to-mouth kisses in a romantic-sexual context. 

With all of that in mind, Arbøll and Rasmussen suggest that the complex history of kissing complicates efforts to clearly link the smooches of the ancients to the spread of certain pathogens. 

“In our opinion, the fact that the sexual kiss was practiced over a large geographical region points to its effect on disease transmission in these periods as having been relatively constant, and not something that suddenly accelerated the spread of pathogens,” Arbøll said.

However, the team noted that the history of kissing can yield important insights about how people in the past responded to infectious diseases. For instance, the researchers cited a letter written neary 4,000 years ago about a woman in a palace harem who became sick with lesions. As a result, people were told to avoid drinking from her cup or sleeping in her bed, which reveals a level of practical knowledge about disease transmission.

We will probably never know exactly when early humans first started kissing, but there is still a lot that we can learn about the history of this beloved pastime and its major role in our modern lives. For instance, Arbøll and Rasmussen hope that future work with ancient DNA could open new windows into the prevalence of kissing before the invention of writing. The team also plans to explore the mystery of why the romantic-sexual kiss appears to have been more common in sedentary and hierarchical societies, such as Mesopotamia.

“Anthropological studies have shown that the sexual kiss is not universally practiced, but there appears to be a tendency for its being practiced in societies with complex social stratigraphy,” Arbøll said. “The cultures from which we have sources describing romantic-sexual kissing in the ancient world span a wide geographical area. At the same time, the written documentation appears in societies which, in periods, maintained a certain degree of social stratification.”

“Consequently, it opens the question as to how widely the romantic-sexual kiss was actually practiced in the ancient world,” he concluded. “We plan to continue our work, and we hope that future studies in general will help to shed further light on these interesting and very human questions.”