Why we love to kiss...from an evolutionary perspective

Okay, right out of the gate I have to confess that I'm not a biologist, evolutionary scientist, or other expert on "why" answers from the scientific perspective.  I'm just a guy whose father was a science teacher with immense curiousity.   And so I have, at particular moments,  found myself wondering why it is that we humans like to 'suck tongue' as they say.  Okay, maybe some of y'all are not that interested in trading saliva with a person of the opposite sex but I'd warrant that the majority of folks in the world at one point or another end up doing just that.  And loving it.   


So at some point I found myself thinking "why would we evolve in such a way that this was an evolutionarily positive activity?" I can think of any number of reasons why it might not be advantageous.    If, for example,  you are wrapped in your sweetie's arms and sucking face,  you are totally vulnerable to being whacked in the head by a competitor or jumped by a predator.  So that makes kissing a negative,  unless you take pains to do it in private.  Oh...wait.  I think I just realized there might be a good reason for people who are attracted to each other to head off into a...ahem...private space.   It's bred into us after millennia!  So we don't get jumped while doing it.


But back to the question of 'why' kissing would be important.  Again, a reminder that I'm not a science researcher.  Just a guy thinking about stuff.   And I find myself thinking about bacteria which inhabit our digestive tract.  You know, the miles long organic obstacle course which food has to traverse in order for us to get nutrition and also to protect ourselves from dangers in the outer world.   The human system for inputting stuff starts right there in front of your teeth and isn't complete until the remains of stuff reach the butt end of the system.   It's an incredible system when you begin to examine it in detail.


So it appears that this system in each of us is also the home and sustenance of a billions of organisms, mostly bacteria,  which personalize our response to things being fed into the gut and provide processing and protection as part of their rent for having a place to reside.  I'm guessing that there are strains of bacterium who have lived with humans for ages and that some of these strains are more compatible than others.   Researchers have identified thousands of these symbiotes living in 'perfect harmony' with humans and have increasingly pegged their roles in human health, from cancer protection to digestive function.


When babies are born,  the humans who care for them engage in frequent behaviors that are likely to transfer some of their symbiotes to the new child.  Kissing and snuggling.  Nose rubbing. Finger sucking.  There are many examples of how adult humans might well transfer and establish cultures of their symbiotes to their offspring.   Not that these would be the only sources of bacterial colonization.  Moms more than anyone would colonize their children with bacterial symbiotes.


So, back to kissing. When a man and a woman kiss,  they exchange chemistry and also biological elements.   They ingest and experience the other person's symbiotes.   And I suspect that this is a theoretical explanation of why we kiss, and why we kiss ferociously when we are truly attracted to someone.  I think that kissing is an opportunity for our symbiotes to get acquainted. A somewhat safe mechanism for weighing whether more intimate bodily fluids should be exchanged. Or for determining that hanging with this person is likely to give you indigestion.  


I'm just saying.  It's a theory  And I'm not a scientist.   But if you've got a better connection between evolution and kissing.  I'm all ears.








Comments

Popular Posts