Why do we kiss?
It is a million-dollar question. I mean, sure, in the modern age, kissing is widely perceived as a manifestation of love and passion. It is an expression of devotion.
But was this always the case? I mean, if you think about it logically, in all honesty, kissing is kind of…gross!
Without the cultural associations of love and warmth that we equate with a kiss, what really is so great about sucking vampirically on another person’s lips or even having a tongue thrust down your throat? It would be a mildly uncomfortable experience; in the worst-case scenario, you could get saliva-borne pathogens injected into your system.
So again, the question arises, given the apparent risks of the practice, why do we enjoy kissing so much?
Well, there are probably several biologically valid reasons for the evolution of kissing among early humans. However, we can still observe one of the most pertinent reasons in birds.
The mother connection
Mouth-to-mouth contact among humans is associated with expressions of love and trust, just as in other life forms. Mother birds feed their children by putting the food into their mouths, chewing on it, and then regurgitating said chewed food into the baby’s mouth directly for it to swallow. Sure, to us, this may seem rather gross, but biologically it makes perfect sense as a child-rearing technique.
Babies have not yet developed the biological faculties that we need to chew and swallow our food fully. They do not yet have fully formed teeth or saliva-producing glands. Swallowing un-chewed food is injurious to health. In such a scenario, in the absence of modern pre-packaged baby formula, what is a mother to do but chew the baby’s food for it? Mouth-to-mouth feeding is observed not only in birds but also in various kinds of mammals, including apes.
Surprisingly, this practice was also quite popular amongst humans before the advent of the baby formula. To wean their babies from breast milk, mothers would often chew solid food, grinding it down in their mouths before directly transferring it to the baby’s mouth.
While this isn’t the healthiest practice due to the possible transfer of pathogens from the mother to the child through saliva sharing, a healthy mother can help the child’s development by chewing its food. The presence of adult saliva helps in the faster digestion of food and the transfer of many essential minerals like zinc that aren’t present in breast milk.
This cultural and psychological association of mouth-to-mouth contact with love, comfort, and nourishment has probably played a role in elevating a kiss to the position it now holds in our society.
The taste-testing theory
Another theory involves the prevalence of something called ‘taste-testing.’ According to this theory, we can subconsciously tell the health and well-being of a potential mate through the taste of their saliva. Now whether this is true or not, I cannot tell you. But it certainly seems like an interesting theory. If this were true, those of our ancestors who were better at kissing selected better mates and could reproduce more often, leading to the widespread acceptance of kissing as a mate-selection technique.
Whatever the origins of the kiss, we cannot deny that it is one hell of an enjoyable activity! So instead of reading online articles about kissing, go out and kiss someone you love right now.