LEILA FADEL, HOST:
Good morning. I'm Leila Fadel. New evidence suggests the first mention of kissing was much earlier than previously known. Some papers suggest romantic kissing began about 3,500 years ago in what is now India. But a new review in the journal Science shows it was mentioned in much older clay tablets from an area that's now modern-day Iraq, a thousand years earlier. The review was put together by a husband and wife from Denmark. Maybe they're subject matter experts. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.