“Chemistry look what you’ve done to me,” Donna Summer crooned in Science of Love, and so, it seems, she was right. Just in time for Valentine’s Day, a panel of scientists examined the mystery of what happens when hearts throb and lips lock. Kissing, it turns out, unleashes chemicals that easestress hormones in both sexes and encourage bonding in men, though not so much in women.
Chemicals in the saliva may be a way to assess a mate, Wendy Hill, dean of the faculty and a professor of neuroscience at Lafayette College, told a meeting of the American Association for the Advancement of Science on Friday.
In an experiment, Hill explained, pairs of heterosexual college students who kissed for 15 minutes while listening to music experienced significant changes in their levels of the chemicals oxytocin, which affects pair bonding, and cortisol, which is associated with stress. Their blood and saliva levels of the chemicals were compared before and after the kiss.
Both men and women had a decline in cortisol after smooching, an indication their stress levels declined.
For men, oxytocin levels increased, indicating more interest in bonding, while oxytocin levels went down in women. “This was a surprise,” Hill said.
In a test group that merely held hands, chemical changes were similar, but much less pronounced, she said.
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