Humans were kissing 4,500 years ago.
Kissing dates back 4,500 years
Scientists say that clay tablets, used in parts of modern Iraq and Syria, provide evidence that locking lips was practised by the human race 1,000 years earlier than previously thought.
The team from the University of Copenhagen suggest kissing happened in the earliest Mesopotamian societies and believe it was common across many different cultures.
It contradicts a previous theory that the earliest evidence of human kissing came in a specific part of Asia 3,500 years ago.
Dr. Troels Pank Arboll, an expert on the history of medicine in Mesopotamia, said: "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.
"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 practiced in multiple ancient cultures over several millennia."