Do you remember your first kiss? Is it painfully, disturbingly seared into your memory like my first kiss is in mine? While the second party who participated in my first kiss will remain anonymous, all I can say is this: it was astronomically awkward, deeply unromantic and even — I hate to say it — clammy.

While my first kiss was clumsy and I will likely never recover, even after all these years, I can only hope that the first kiss ever in history was spared of such embarrassment.

Recent research suggested that kissing as we do now — romantic in nature — dated back to India 3,500 years ago, according to The Washington Post.

But newer research, specifically a review paper by Danish husband and wife research duo Troels Pank Arboll and Sophie Lund Rasmussen, “says that this style of kissing is also mentioned in clay tablets from Mesopotamia that predate the Indian texts by about a thousand years,” per The Washington Post.

Where did kissing originate from?

The earliest kiss recorded dates back “at least 4,500 years to Mesopotamia,” according to The Washington Post.

Arboll and Rasmussen reportedly began their research after chatting about a research paper about herpes. The research “had noted a shift in the transmission of the virus during the Bronze Age (2,000 to 700 B.C.), ‘potentially linked’ to new cultural practices ‘such as the advent of sexual-romantic kissing.’”

Arboll, an assistant professor of Assyriology at the University of Copenhagen, told The Washington Post, “I said to Sophie that I knew we had something older. And then I started digging a bit into that.”

The researchers eventually found that “lip kissing was documented in ancient Mesopotamia and Egypt from at least 2500 B.C.E. onward,” according to their research paper.

“In the earliest texts in the Sumerian language, kissing was described in relation to erotic acts ... and the locus was the lips,” the paper continues.

“In the Akkadian language, references to kissing can be subdivided into two distinct groups, the first designating friendly and familial affection, describing a display of submission or respect through the act of kissing the feet or the ground, and the second being an erotic action with the lips as the primary locus.”

In Mesopotamian culture, kissing outside of marriage was most likely seen as a faux pas. The researchers came across two stories: “One describes how a married woman was almost led astray by a kiss from another man, and the other describes an unmarried woman swearing to avoid kissing and having sexual relations with a specific man.”

It’s worth noting that Rasmussen and Arboll strongly believe that kissing “did not emerge abruptly or in a specific society, but appears to have been practiced in multiple ancient cultures,” according to The Washington Post.

Why did humans start kissing?

“I came across research suggesting that the purpose of kissing, why it could have evolved, is that it serves as an opportunity to evaluate your partner,” Rasmussen, an ecologist at the University of Oxford’s Wildlife Conservation Research Unit and Aalborg University in Denmark, said. “If you kiss somebody with poor teeth, they tend to have bad breath.”

Some researchers have other theories. According to BBC, there are two theories that “stem from the idea that as babies we have an innate liking for lip touching.” The first theory suggests that humans liken kissing, or “lip touching,” to breastfeeding — which is, per BBC, an “innate” reflex “to everyone.”

The second is based on “pre-mastication food transfer.” Some believe that mothers and children “bond over lip-on-lip kissing” because ancient mothers “might have pre-chewed our food for us in our early years, and transferred it directly into our mouths.”

What is the history of humans kissing?

While the earliest recorded kiss was over 4,500 years ago, there are various references to kissing throughout history — both romantic and platonic. According to How Stuff Works, “There aren’t many records of kissing in the Western world until the days of the Roman Empire.”

In Roman culture, kisses were often used in greeting. There were three categories of kisses among the Romans: osculum, a kiss on the cheeks; basium, kiss on the lips; savolium, a deep kiss. It was also customary couples to officially become betrothed by “kissing passionately in front of a group of people” — likely why married couples kiss at the end of their wedding, per How Stuff Works.

Kissing was also prominent in early Christianity. According to How Stuff Works, “Christians often greeted one another with an osculum pacis, or holy kiss.” It was believed that a holy kiss “caused a transfer of spirit between the two people kissing.” Researchers believed that the holy kiss was meant to “establish familial bonds” between church members.

The holy kiss was reportedly a part of Catholic mass until 1528. The Catholic Church integrated a pax board during the 13th century, “which the congregation kissed instead of kissing one another,” per How Stuff Works.

But romantic kissing, William Jankowiak, professor of anthropology at the University of Nevada at Las Vegas, told The Washington Post, was likely “discovered amongst elite in complex societies (hierarchal, market systems with writing) and diffused outward.”

Kissing “was in keeping with”, according to Jankowiak, “the elite pursuit of pleasure.”

Rasmussen and Arboll note that kissing likely played a bigger role than expressing romantic or platonic love throughout history — it likely spread diseases, too. “Reaching beyond its importance for social and sexual behavior, the act of kissing may have played a secondary and unintentional role throughout history in facilitating the transfer of orally transmitted microorganisms, potentially causing disease.”