When we think of a kiss, we usually picture romance, affection, or emotional bonding between humans. But new research suggests that the world first kiss may have happened 20 million years ago, long before humans existed. Early primates like chimpanzees, bonobos, and orangutans were already using mouth-to-mouth gestures to bond, comfort, and reconcile. This discovery turns our ideas about kissing upside down, showing that it’s more than culture—it’s a deeply rooted biological instinct.
World First Kiss
Scientists studied mouth-to-mouth behaviours across multiple primate species and found that affectionate gestures are common. Chimpanzees kiss to make up after fights, bonobos use it for social bonding, and orangutans occasionally show similar behaviours during grooming. By mapping these gestures across the ape family tree, researchers concluded that the common ancestor of great apes—the pioneer of the world first kiss—likely engaged in mouth-to-mouth contact around 20 million years ago. Humans inherited this behaviour, turning it into the romantic and social gesture we know today.
Why Early Apes Kissed
Affectionate kissing-like gestures likely helped early apes maintain social harmony. They may have been used to repair conflicts, comfort group members, build trust, or reinforce alliances. Some scientists believe kissing evolved from grooming, which was essential for hygiene and social bonding. Others think saliva contact allowed individuals to check a partner’s health. Whatever the reason, the behaviour was effective and persisted through millions of years of evolution.
