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The Science of Why We Kiss

Oxytocin, dopamine, and what the hineys of monkeys have to do with the faces of our lovers.

“Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves,” Einstein allegedly smirked. “Like a bee that settles on the fragrant pistils of a flower, and sips in the nectar for honey, so should you sip in the nectar from between the lips of your love,” Hugh Morris counseled in The Art of Kissing, his entertaining 1936 guide for lovers. The first kiss in cinema both scandalized and tantalized audiences when it appeared on the silver screen in 1896. But why, exactly, do we like kissing so much?

In this illuminating short video, based on the altogether fascinating book The Science of Kissing: What Our Lips Are Telling Us (public library) by our mutual friend Sheril Kirshenbaum, Joe Hanson of It’s Okay To Be Smart, who has previously explored the mathematical odds of finding your soulmate, takes us through the neurochemistry, evolutionary biology, and social science of kissing — all with the necessary disclaimer that we know much less than we don’t, a vital reminder that science and human knowledge are driven by “thoroughly conscious ignorance.”

In the book, Kirshenbaum writes:

Scientists are not exactly sure why we kiss. This may be in part because they have not even definitively decided what a kiss is. Unlike most other areas of scientific investigation, there’s no accepted “taxonomy,” or classification system, for different kinds of kisses and closely related behaviors. What’s more, you don’t find the experts crunching the numbers and figures on kissing across world cultures, as researchers would surely do if they wanted to get a handle on the available data. Why so little analysis of osculation? Perhaps kissing seems so commonplace that few of us have paused to reflect on its deeper significance. Or it’s possible the subject has been intentionally avoided under the microscope given the challenges of interpreting what a kiss really means.


Because a kiss brings two individuals together in an exchange of sensory information by way of taste, smell, touch, and possibly even silent chemical messengers called pheromones (odorless airborne signals), it has the potential to provide all kinds of insight into another person. So even when our conscious minds may not recognize it, the act can reveal clues about a partner’s level of commitment and possibly his or her genetic suitability for producing children.

Dive deeper with The Science of Kissing, then take a vintage sidewise step with The Art of Kissing.

Published February 13, 2014




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