A STUDY by Oxford University researchers suggests kissing helps us size up potential partners.

And the boffins say that once in a relationship, snogging may be a way of getting a partner to stick around.

“Kissing in human sexual relationships is incredibly prevalent in various forms across just about every society and culture,’ said Rafael Wlodarski, the student who carried out the research in the Department of Experimental Psychology at Oxford University. “Kissing is seen in our closest primate relatives, chimps, but it is much less intense and less commonly used. So here’s a human court-ship behaviour which is incredibly widespread and common and, in extent, is quite unique.

“And we are still not exactly sure why it is so widespread or what purpose it serves.”

To understand more, Mr Wlodarski and Prof Robin Dunbar set up an online questionnaire in which more than 900 adults answered questions about the importance of kissing in both short-term and long-term relationships.

Mr Wlodarski said: “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 (to initiate sex for example); and that it is useful in keeping relationships together.

“We wanted to see which of these theories held up under closer scrutiny.’ The researchers report their findings in two papers, one in the journal Archives of Sexual Behavior and the second in the journal Human Nature.

They were funded by the European Research Council.

The survey responses showed that women rated kissing as generally more important in relationships than men.

Men and women who rated themselves as being attractive, or who had more short-term relationships and casual encounters, also rated kissing as being important.