One of the many podcasts that I listen to on a regular basis is Stuff You Should Know (SYSK), hosted by Josh Clark and Charles W. Bryant and produced by the people over at HowStuffWorks.com. SYSK is pretty informative stuff and the topics cover a grand range of things. Like how humanity seems to have hit a wall in terms of new ideas, how octopi work, and how Route 66 works.
Because it's Wednesday, and that obliges me to write on what it is that I'm currently learning about I've decided to go with kissing. The SYSK podcasts are generally 30 minutes long, but this one has left an imprint the same way the coverage of biospelology did.
Now, I already know that within the English language the word "kiss" goes all the way back to Old English ("cyssan," c's are hard in OE and y's are a kind of "ooo" sound, so it even sounds similar). But I never really gave much thought as to where the practice came from or if it's something that's just always been around.
The two theories that SYSK puts forward are that kissing is either a learned behaviour, or it's something instinctive.
One example given for the case of kissing being learned behaviour is that pre-historic mothers essentially regurgitated food for their children and since they passed it directly into their offspring's mouth from theirs this imprinted a pleasurable and nourishing experience onto the developing mind.
The other theory in support of kissing as a learned behaviour that gets mentioned is that kissing was limited to the area that's now India and that Alexander the Great brought it back to Greece after having conquered his way to South-East Asia. This theory has some tangible evidence behind it, though circumstantial, in that the earliest record of kissing is found in Bhagavad Gita, the section of the larger epic, the Mahabharata, that is dated between 200 BC and 200 AD (wiki ref 1).
The other theory that it's instinctive gets tied into the idea that kissing is an ancient means of assessing a potential mate's immunities. This assessment, Josh and Chuck explain, is important because a couple's offspring will inherit both parents' immunities; thus, for the healthiest possible offspring, it's important that the parents have differing immunities.
This theory gets some serious back-up, I think, when Josh mentions the remnants of an organ of some kind that was instrumental in the kind of hormonal sensing that assessing a make-out partner's immunities requires but that is now dormant.
However, as flimsy as sociological stats can be, in a survey of all contacted societies, 10 percent of them reported no kissing practices. The fact that these societies might not be the types to "kiss and tell" is mentioned, and honestly, I think that this stat alone means little - it would be seriously buttressed by some lateral studies into societal modesty and general regard for sexual activity.
Another intriguing thing from this version of the podcast is that Protestantism ultimately forced what was known as the "holy kiss" out of Catholic mass. The idea behind the practice was that the kiss signified peace and a conscious effort to "not let your heart withdraw from [your brother's]," as St. Augustine explained (wiki ref 2).
SYSK suggests that the holy kiss was about passing the spirit from one person to another, an interpretation that seems sound since the dove is a sign of peace and the kiss is meant to signify a lasting peace between the kissing parties.
Rather than give the rest of the episode away, if you've been intrigued by any of this you should give it a listen.
What I've learned from all of this is that social practices shouldn't be taken for granted since some interesting speculation and curious theories are to be found where hard scientific answers are wanting.