Lip kissing is an act that’s so natural and common in many present-day societies it is easily taken for granted. But it’s not actually clear whether people have always been kissing, or whether its ...

Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Humans are born with instincts for crying and smiling, but not for ...

Kissing feels instinctive and intimate, yet scientists now argue it is a surprisingly recent and uneven addition to human behavior. Instead of a single romantic origin story, the evidence points to a ...

In the Western world, Valentine’s Day expressions of affection are closely linked to mouth-to-mouth kisses. I remember feeling envious years ago when a colleague found a card in his pigeon-hole ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. “The meeting of ...