The romantic kiss may have existed for 1,000 years longer than previously estimated, dating back to ancient Mesopotamia, a new scientific article suggests.
The article, published in the journal Science on Thursday, looked at surviving clay tablets from Mesopotamia and dated the earliest recorded kiss to 4,500 years ago.
"In ancient Mesopotamia, which is the name for the early human cultures that existed between the Euphrates and Tigris rivers in present-day Iraq and Syria, people wrote in cuneiform script on clay tablets," study author Troels Pank Arboll, an expert on the history of medicine in Mesopotamia, said in a news story from the University of Copenhagen.
"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."
The researchers say recent studies have suggested that kissing originated in a specific geographical area in South Asia 3,500 years ago and spread to other regions.
But in their article for Science, they suggest that kissing was already well established in the Middle East.
"Therefore, kissing should not be regarded as a custom that originated exclusively in any single region and spread from there but rather appears to have been practised in multiple ancient cultures over several millennia," Arboll said.
Sophie Lund Rasmussen from the University of Oxford and a co-author of the study says the closest living relatives to humans — bonobos and chimpanzees — also engage in kissing, which could explain why it is a fundamental human behaviour found across cultures.
It also inadvertently helped the spread of viruses, the authors say.
"If the practice of kissing was widespread and well-established in a range of ancient societies, the effects of kissing in terms of pathogen transmission must likely have been more or less constant," Rasmussen said.
Kissing also may have played an "unintentional role" in the transmission of certain viruses such as herpes simplex virus 1, which spreads by oral contact and causes infections known as cold sores around the mouth.
"There is a substantial corpus of medical texts from Mesopotamia, some of which mention a disease with symptoms reminiscent of the herpes simplex virus 1," Arboll said.
The texts, for example, reference a disease known as bu'shanu, which bears some similarities to the symptoms caused by herpes simplex virus.
However, different "cultural and religious concepts" would have influenced those ancient medical texts, he added, meaning they cannot be read at face value, he added.
