New research into Ancient Mesopotamia suggests people kissed romantically 4,500 years ago.The finding would mean humans began kissing 1,000 years earlier than previously thought.The article published in Science reveals kissing did not originate in one region, scientists say.LoadingSomething is loading.Thanks for signing up!Access your favorite topics in a personalized feed while you’re on the go. download the appRecords of the very first romantic kiss date back at least 4,500 years ago, new evidence suggests, about 1,000 years earlier than scientists previously thought. In a new article published in Science, researchers from the University of Copenhagen and the University of Oxford revealed their findings on the “ancient history of kissing” after drawing on clay tablets and other materials from early Mesopotamian societies. Ancient Mesopotamia is considered to be roughly the land that is now modern-day Iraq and Syria. It was previously believed the earliest evidence of romantic-sexual lip kissing in humans originated in South Asia 3,500 years ago. Then it spread to other regions, according to the University of Copenhagen. The new research challenges these theories and suggests kissing was common across many different regions and cultures, starting much earlier.  In examining the clay tablets written in cuneiform script in the research, the scientists noted that in the Akkadian language, kissing is divided into two groups: “friendly and familial affection” and “erotic action.” “Many thousands of these clay tablets have survived to this day, and they contain clear examples that kissing was considered a part of romantic intimacy in ancient times, just as kissing could be part of friendships and family members’ relations,” Troels Pank Arbøll, an expert on the history of medicine in Mesopotamia and co-author of the article, said in a statement. “Therefore, kissing should not be regarded as a custom that originated exclusively in any single region and spread from there but appears to have been practiced in multiple ancient cultures over several millennia,” Arbøll said.Thomas Lohnes/Getty Images While the exact origins of romantic kissing remain uncertain, the study said, there is some possible evidence that it may have occurred even before the advent of writing. “In fact, research into bonobos and chimpanzees, the closest living relatives to humans, has shown that both species engage in kissing, which may suggest that the practice of kissing is a fundamental behavior in humans, explaining why it can be found across cultures,” Sophie Lund Rasmussen, co-author of the study, said. The researchers also examined sexually-transmitted diseases in early kissing and its “unintentional role” in the transmission of herpes simplex virus 1 — also known as cold sores. Arbøll noted a “substantial corpus of medical texts from Mesopotamia” that mentioned symptoms reminiscent of the virus. While this cannot be taken entirely “at face value” due to the influence of certain religious and cultural overtones, he said, “it is nevertheless interesting to note some similarities between the disease known as buʾshanu in ancient medical texts.”