Sunday, April 20, 2008

The science of kissing

According to a great article about kissing in the Scientific American, Finns don’t kiss very much either. They get into a sauna nude with a whole community of people but as a nation, Finland doesn’t buy into osculation, which is the scientific— and rather inept term—for kissing. Neither do certain tribes in Polynesia, Madagascar and Tierra del Fuego. Some Mongolian tribes breathe down on their child’s head in lieu of a kiss.

All of which led me to question the whole notion of a lip-lock. After all, you don’t need kissing for the survival of the species. Not technically anyway. People use other parts of their anatomy for that. A kiss is delicious and pleasurable, yes, but what purpose does it serve in the evolutionary sense?

Freud believed that kissing was just an offshoot of the suckling reflex. We suckle as babies; we kiss as adults, proving once again that we never grow up. Anthropologists feel that, as with many things, we learned from the primates before us. Chimps, for instance, mouth feed their young. It took a few aeons and several species to figure out that the mouth could be used for more pleasurable activities than passing on food particles.

Birds still do this, but we humans have invented cutlery for the whole feeding thing. We use our lips to masticate, yes, but also to osculate. Ergo, the 21st century version where Harry and Sally, or Sunehri and Aryan, pucker up.

Other studies have also advanced the view that kissing helps in the selection of a mate. When you kiss someone, your orbicularis orbis muscle contracts, allowing you to pucker. Meanwhile, blood rushes to your lips, your body gets warm, your neural synapses fire away and levels of the cortisol ‘stress’ hormone drop.

If you are stressed out, kissing someone will lower your cortisol ‘stress’ hormone and increase the pleasant oxytocin levels, which may help explain all those office romances that happen as deadlines approach.

One unusual finding was that while men uniformly got a high oxytocin count after a kiss, women didn’t. This study by psychologist Wendy Hill and Carey Wilson of Lafayette College concluded that women needed something more than a kiss; something more romantic—such as flowers, candles, compliments, serenades, or diamonds—to get them high. All men needed was a kiss.
A single kiss can also make or break a date. You may be focusing on getting your tongue into the other person’s mouth but your brain is engaged in all kinds of subliminal judgements: Is this person good enough to bear my children; can I stand looking at this person for the rest of my life; and the deal breaker—will this person laugh at my lame jokes; and laugh as if they mean it. All these judgements happen in the span of a single kiss.

Meanwhile, your pheromones are firing and driving you both crazy: androstenol from the male sweat and copulins (a wonderfully appropriate scientific word for a change) from the female vagina. These neurochemicals work on a molecular level in weird ways. Studies have shown that if you give women a whole series of sweaty T-shirts to sniff, they will choose the shirt of a man whose immune system complements theirs. Weird, isn’t it?

In fact, evolutionary biologists would like to have you believe that kissing is just a more socially advanced method of choosing a mate.

1 comment:

Daniel Rossi said...

Interesting, but let me correct one thing:
There are no "tribes" in Tierra del Fuego anymore; native people there are extinct since long ago. It seems that part of the article is a "little" outdated :)