Kissing is an act of love seen in cultures across the globe, with its history spanning many thousands of years. There are many theories as to how this act – representing love, affection, friendship and even respect – came about. The two most popular theories are the ideas that early humans in the Stone Age licked each other’s faces to obtain salt from sweat, or that it originated from ancient Romans. Roman soldiers kissed their wives as soon as they returned from war, to check whether there was the smell of alcohol (which was banned for women) or another man.
Using historical evidence from ancient texts from India and old paintings from China, it can be deduced that even in Asia the history of kissing is over 2000~4000 years old.
The human lip contains many nerve endings, making it one of the most sensitive part of skin on the body. Also, kissing stimulates the secretion of dopamine and oxytocin, chemicals responsible for invoking the feeling of love and happiness, causing an electric sensation (research states that the brain interprets it in a similar way to using cocaine).
It has already been proven that kissing lowers perceived stress and frequent kissing between couples lowers cholesterol and strengthens the cardiovascular system. Furthermore, it has been discovered that over 295 colonies of bacteria can be transferred per kiss (95% of which are harmless, but diseases such as glandular fever or herpes can be transmitted this way).
Some believe that the act of kissing came about to simulate the feeling of breastfeeding, an act ingrained in the subconscious mind (the same point is made regarding cigarette use).
This romantic behaviour is also seen in nature. Many bird and mammal mothers transfer pre-masticated food to their young this way, and calves kiss each other after drinking milk to prolong the sensation of breastfeeding. Even insects are found to “kiss”, such as ants that bring up food from their second stomach, the “social stomach”, to feed fellow ants that need food.