Are Humans the Only Animals That Kiss? An Evolutionary Biologist Explains

A 2025 Oxford-led study suggests kissing likely began in a common ancestor of large apes around 21 million years ago.

The behavior may have been inherited by humans and Neanderthals, making it far older than many assume.

Researchers think kissing could have evolved from grooming or other bonding behaviors, not just romance.

The article highlights kissing as an ancient primate trait with possible social benefits and infection risks.