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.
The experiment was conducted in a student health center, Hill noted. She plans a repeat "in a more romantic setting."
Hill spoke at the session on the Science of Kissing, along with Helen Fisher of Rutgers University and Donald Lateiner of Ohio Wesleyan University.
Fisher noted that more than 90 percent of human societies practice kissing, which she believes has three components
- the sex drive, romantic love and attachment.
The sex drive pushes individuals to assess a variety of partners, then romantic love causes them to focus on an individual, she said. Attachment then allows them to tolerate this person long enough to raise a child.
