Give Us a Kiss: The Science of Liplocking
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Ahh, the kiss. What a wonderful pastime. Who doesn't enjoy losing themselves in a passionate lip-lock, or the anticipation of a first kiss with a new love interest? And certainly veteran kissers will attest to the physical and emotional benefits of the smooch. But why is it - exactly - that we kiss like no other animal? Have we always kissed? Is kissing instinctual? Where did kissing come from and what benefits, beyond the obvious, might a kiss offer us?
For researchers, kissing is a wonderful area to study - enlisting participants is easy, and the findings are always relevant. The science of kissing even has a name: philematology. Recently, Wendy Hill, dean of the faculty and a professor of neuroscience at Lafayette College in Pennsylvania, conducted two experiments on kissing. Hill discussed her findings at a meeting of the American Association for the Advancement of Science along with Professor Ruth Fisher of Rutgers University and Donald Lateiner of Ohio Wesleyan University. Her first experiment involved 15 heterosexual couples, ages 18 to 22, interacting for about 15 minutes in the student health center. The control group held hands and talked while music played. The experimental group kissed (open-mouthed) during the music.
The second experiment involved nine heterosexual couples and three lesbian couples interacting in ways similar to the first experiment group. The primary difference was that rather than the health center, they were in a secluded room with low light, jazz music, and flowers. Hill was specifically wondering about two chemical changes that take place during a kiss, and how they varied between men and women. The chemical oxytocin has to do with social and pair bonding, and the chemical cortisol measures stress.
The surprise result was that, in the first experiment, the oxytocin levels (indicating feelings of bonding) went up in men, and down in women. Researchers had expected the exact opposite. One theory is that the women's feelings of closeness were disrupted by the artificial setting of the health center. Oxytocin levels from the second experiment are still being reviewed. All of the participants lowered their cortisol (stress) levels during the experiments, although the decrease was greater for couples in more established relationships. The heterosexual women expressed greater feelings of intimacy than both the men and the homosexual women. All participants reported equal satisfaction from kissing their significant others.
Evolutionary Psychology: Why We Kiss
Now for a little lesson in philematology. Kissing is thought to have evolved from an early human method of feeding babies. Without the convenience of pre-mashed food, mothers might have chewed food, and then transferred it directly to the mouths of their infants. Yum. Today's kissing is primarily a way to share affection, and often linked to our sexuality. This is true for at least 90 percent of global cultures. Kissing at the beginning of a relationship serves to communicate details through taste, smell, texture, and sounds that determine whether the two people will want to stay together. According to Fisher, kissing stimulates the three components of human mating: sex drive to encourage the seeking of a mate, romantic love to promote a particular person, and attachment to support the conception and nurturing of children.
"Kissing is not just kissing. It is a major escalation or de-escalation point in a powerful process of mate choice," said Fisher. "When you kiss, an enormous part of your brain becomes active. Romantic love can last a long time, if you kiss the right person."
Men Vs Women
From an evolutionary and subconscious standpoint, men and women are thinking about different things during a kiss. Women are collecting information about their partner's immune system, hoping to detect one with a makeup different from their own. Men are trying to transfer as much testosterone-filled saliva as possible, as the chemical increases sex drive, bettering the chance of copulation.