One Fearless Kiss

. . . the word is love.
Surely one fearless kiss
would cure the million fevers,
a stroking brush
the insensitive refuse
from the burning core.

W. H. Auden

The following is excerpted from an article by Chip Walter, entitled Affairs of the Lips: Why We Kiss, first published in the January 2008 issue of Scientific America.

Since kissing evolved, the act seems to have become addictive. Human lips enjoy the slimmest layer of skin on the human body, and the lips are among the most densely populated with sensory neurons of any body region. When we kiss, these neurons, along with those in the tongue and mouth, rocket messages to the brain and body, setting off delightful sensations, intense emotions and physical reactions.

. . . Kissing unleashes a cocktail of chemicals that govern human stress, motivation, social bonding and sexual stimulation.

To the extent that kissing is linked to love, the act may similarly boost brain chemicals associated with pleasure, euphoria and a motivation to connect with a certain someone. In 2005 anthropologist Helen Fisher of Rutgers University and her colleagues reported scanning the brains of 17 individuals as they gazed at pictures of people with whom they were deeply in love. The researchers found an unusual flurry of activity in two brain regions that govern pleasure, motivation and reward: the right ventral tegmental area and the right caudate nucleus. Addictive drugs such as cocaine similarly stimulate these reward centers, through the release of the neurotransmitter dopamine. Love, it seems, is a kind of drug for us humans.

. . . Despite all these observations, a kiss continues to resist complete scientific dissection. Close scrutiny of couples has illuminated new complexities woven throughout this simplest and most natural of acts—and the quest to unmask the secrets of passion and love is not likely to end soon. But romance gives up its mysteries grudgingly. And in some ways, we like it like that.