John Lennon was wrong — a kiss is not just a kiss. Earthlings have been puckering up from time immemorial: recent research by scientists now places the origins of the kiss between 16 and 21 million years ago, with Neanderthals, ants and even fish all having their own versions of the smooch. Surprisingly, the research findings insist that the kiss offers little evolutionary advantage: it is a decorative quirk that somehow managed to escape evolution’s elimination of the vestigial. That claim feels oddly blinkered. Can a behaviour survive across species, continents and millennia unless it performs a function? Perhaps science should turn to history and culture for some answers about the enduring appeal of a kiss.
Archaeological and literary records show that communities have had far more faith in the lip-lock than, say, evolutionary biologists do. The written record of kissing reveals complexity rather than triviality. South Asian treatise, such as the Kama Sutra, notes more than a dozen distinct types of kisses. Roman writers divided kisses into osculum, basium and savium, thereby differentiating duty from affection and overt desire. The kiss was neither a furtive activity only. In ancient Mesopotamia, humans kissed in both intimate and familial settings. A pattern emerges from these records. Different
societies turn the same basic movement of lips into a nuanced code for rank, respect, erotic interest, kinship, reconciliation or allegiance. These reflect a long-held awareness that a kiss carries social intent and emotional communication that, evidently, continues to elude science.
In fact, the kiss has served as an ancient mechanism for species to build alliances, mediate conflict and strengthen group cohesion. Bonobos kiss to defuse tension, chimpanzees use it to reconcile after acts of aggression, and orangutans do it to express affection. Negotiation, reassurance and peacekeeping would not have been effective without the kiss. Intriguingly, on occasion, this marker of affection and solidarity has been known to do the opposite: that is, symbolise betrayal. The Judas kiss, supposedly inspired by Judas kissing Christ to identify him to his adversaries, is a metaphor that retains its potency across time and culture. Little wonder then that humans could not resist adding poetry, cinema and music to an act that has such layers. The famous photograph of a sailor kissing a nurse, which was taken by Alfred Eisenstaedt for Life magazine on the occasion of America’s victory over Japan in the Second World War, is a testament to the kiss’s ability to straddle layers of reality. There is also the kiss’s function as a tool for subverting claustrophobic moral opprobrium: some years ago, the ‘Kiss of Love’ campaign began from Kochi and spread to other cities, including Calcutta, to protest against the moral policing by right-wing vigilantes. A kiss a day can even keep the doctor away. The calming of the nervous system by a drop in cortisol levels and the release of oxytocin can be attributed to the magic movement of the lips.
The kiss, then, is no evolutionary quirk. It has survived millions of years precisely because the tiny act carries in it an oversized load of meaning.
