Articles - Features

Ninety percent of all people in the world kiss. Even though it inevitably  involves the exchange of saliva and mucous membrane and is most likely to have evolved from a mother's need to premasticate food before transferring it to the mouth of her offspring, the habit has survived.

Kissing is a complex behaviour that requires the coordination of orbicularis oris, the facial muscle that lets you pucker up, zygomaticus (both major and minor) and levator labii superioris to pull your lips upwards, depressors labii inferioris and anguli oris to pull your lips down, lateral pterygoid to pull your jaw down and massiter, temporalis and medial pterygoid to close your mouth. In the event that you choose to keep your mouth open during the act, genioglossus, styloglossus, palatoglossus and hyoglossus engage to get your tongue moving.

The physiology of the process is relatively easy to unbundle. What is less easy to work out is why we do it. In 1680, German polymath, Martin von Kempe published a 1000-page book called Opus polyhistoricum, dissertationibus XXV. de osculis dedicated to the study of just 20 different kinds of kissing, including the kissing of the Pope's foot and the kiss of contagion. Still, von Kempe's hefty tome could not exhaust the myriad possibilities that humans have added to the vocabulary of mouth-to-mouth communication since: blown kisses, air kisses, arse kissing. The list is endless.

Blogger Sheril Kirshenbaum is attempting a definitive work on the subject, a book called The Science of Kissing. On her blog, The Intersection she is running an experiment that invites readers to look at 15 photos of people kissing, and to categorise them into the type of kiss: friendly, erotic, or relationship.

If the wisdom of the crowd that comes via the net is to be trusted  Kirshenbaum hopes that the results, to be tabled in her book, will give fresh insights into the fine art of osculation.