"Kissing in human sexual relationships is incredibly prevalent in various forms across just about every society and culture," said Rafael Wlodarski, from The Social and Evolutionary Neuroscience Research Group in the Department of Experimental Psychology, who led a recent study. Researchers investigated smooching by conducting an online survey in which more than 900 adults answered questions about the role of kissing. The survey responses, reported papers in the journal Archives of Sexual Behaviour and Human Nature, showed that women rated kissing as generally more important in relationships than men.
Men and women who rated themselves as being attractive, or who tended to have more short-term relationships, also saw kissing as more important.
"There are three main theories about the role that kissing plays in sexual relationships: that it somehow helps assess the genetic quality of potential mates; that it is used to increase arousal; and that it is useful in keeping relationships together.
We wanted to see which of these theories held up under closer scrutiny," Wlodarski said.
Since, according to the survey, both groups also place a high value on kissing, it suggests that kissing may help in mate assessment. Co-author Robin Dunbar, said: "Mate choice and courtship in humans is complex. It involves a series of periods of assessments where people ask themselves, 'shall I carry on deeper into this relationship?'.
"Initial attraction may include facial, body and social cues. Then assessments become more and more intimate as we go deeper into the courtship stages, and this is where kissing comes in." The study showed very little evidence to support the hypothesis that the primary function of kissing is to elevate levels of arousal.