Kissing: it’s a normal part of life. But few people understand its true significance. The Science of Kissing (2011) explains why kissing is so rooted in both human and animal biology, what happens physiologically when we do it and why it’s a lot more important than you may realize.
Nearly everyone enjoys kissing, but most of us rarely stop to wonder why. The answer is deeply rooted in our biology.
One of the first physically enjoyable sensations we experience is being nursed by our mothers; the use of our lips comes naturally to us. Babies suck their thumbs even when they’re in the womb and purse their lips for nursing as soon as they’re born – the very same lip movement as kissing!
Nursing is very comforting for a baby. It usually takes place in a safe and calm environment, so the baby grows to associate soft pressure on the lips with feeling secure and loved.
Premastication, the process of feeding mouth-to-mouth, was the most practical way to feed babies and toddlers for thousands of years, which also biologically linked positive feelings with lip contact.
Premastication might sound gross to us in the modern world. However, mechanically mashed baby food is a rather recent invention, so pre-chewing food used to be the best way to transition out of breast-feeding.
Other animals like apes and birds use premastication too, and it’s still used by humans in some areas. The first known written records of the practice date back to ancient Egypt, and one study found that 39 out of 119 modern communities investigated still use premastication for feeding, as part of a ritual, for various reasons including disease prevention.
Premastication doesn’t only deepen a baby’s feelings of security, attachment and love. It also transfers the positive association of mouth-to-breast contact to mouth-to-mouth contact, further strengthening the emotional and behavioral foundation for kissing that develops later in life.
And our penchant for kissing isn’t only about feeling love; find out more in the next blinks!