Is smooching fundamentally weird? Kissing is older than humanity. Yet scientists are divided on why we do it and where it came from. Locking lips might be much stranger than it seems.
First kiss ‘was 21 million years ago’
Kissing cousins: The Barbary macaque, also known as the Berber monkey, frequently engages in lip-to-lip contact that resembles kissing, primarily as a form of social greeting and affectionate bonding.