Kissing: nature or nurture?

Why do humans kiss?  Is it a learned behavior or does it serve a primary function in evolution of the human species?  In a 2011 issue of Discover Magazine, writer Sheril Kirshenbaum shared “20 things you didn’t know about kissing.”  Some highlights from Kirshenbaum’s findings:

•  Kissing is not universal, points out Kirshenbaum, “leading some experts, like anthropologist Vaughn Bryant of Texas A&M to think that it might actually be a learned behavior.”

•  Citing the work of evolutionary biologist Claus Wedekind (Switzerland’s University of Lausanne), Kirshenbaum explains that “being close enough to kiss helps our noses assess compatibility.”  Wedekind’s study, said Kirshenbaum, “reported that women prefer the scents of men whose immunity-coding genes are different from their own.  Mixing genes that way may produce offspring with a stronger immune system.”

•  A vote for nature?  Said Kirshenbaum: “. . . two-thirds of all people turn their head to the right when kissing, according to psychologist Onur Gntrkn of Ruhr-University Bochum in Germany.  This behavior may mirror the head-turning preference observed in babies and even in fetuses.”

•  Women vs. men?  A study cited by Kirshenbaum found that “when deciding whether to kiss someone, women pay much closer attention than men do to the breath and teeth of their partner.” The work cited was performed by evolutionary psychology Gordon Gallup (State University of New York, Albany).