The origins of kissing were a subject for much debate until recent times. Historians initially believed that kissing began with the Romans, when, returning from a hard day at the amphitheatre, Roman husbands would kiss their wives to see if they had been into the red wine. Following this theory, scientists proclaimed that people kissed because when their lips met a pleasurable electric current was generated. New studies have shown this to be completely untrue. (But when two people embrace, hormones are released into the blood stream, which immediately induce a sense of euphoria.) In these enlightened days before the millennium the truth behind why we lip-lock has been revealed.
Back in Prehistoric times it was important to select a mate with a good immune system to further the species with. So, as barbaric as it may sound, our ape-like ancestors would taste each other’s saliva in order to find a healthy prospect. Saliva contains levels of a compound found in the body called immunoglobulin (IgA). IgA binds to bacteria and triggers the immune system to destroy them. Stress and anxiety levels can also be measured through saliva by monitoring the breakdown products of a neurotransmitter called noradrenaline, high levels of which indicate recent trauma. So instead of indulging themselves in the kissing purely for the joy of it, our predecessors were actually using smooching as a test of the health of their partner. Somehow their nervous system was able to recognise a suitable match purely through the exchange of, er….. spit.
Back in 2002, kissing is still linked to procreation, but is also indulged in as an activity all on its own. However the lessons learnt from the discovery of the origins of kissing has assisted science immensely. Many tests can now be performed on animals and humans alike in a non-invasive manner, and immunity can be successfully monitored through saliva levels, rather than the more traditional blood or urine.