Have you ever wondered why kissing is so important in a romantic relationship? It turns out it’s complicated!
After conducting an online survey with 902 people aged 18-63 years in North America and Europe, researchers at Oxford University have concluded that kissing may help people assess potential mates and then maintain the relationship.
“Kissing in human sexual relationships is incredibly prevalent in various forms across just about every society and culture,” according to Rafael Wlodarski, a DPhil student who has led the research.
“Kissing is seen in our closest primate relatives, chimps and bonobos, but it is much less intense and less commonly used.
“So here's a human courtship 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.”
Rafael explains that there are three main theories about the role that kissing plays in sexual relationships.
“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.”
Participants in the survey were asked about their attitudes toward kissing in different phases of romantic relationships. They were then asked about their sexual history: for example, whether they had been more inclined toward casual encounters or long-term, committed relationships. They also had to define their “mate value” by assessing their own attractiveness.
The participants generally rated kissing in casual relationships as most important before sex, less important during sex, even less important after sex and least important “at other times.”
Previous research has shown that three types of people tend to be choosier in selecting mates who are genetically fit and compatible:
- women
- those who rate themselves highly attractive, and
- those who favour casual sex.
The people in these groups said that kissing was important mostly at the start of a relationship as a quick, easy way to sample a partner’s suitability.
After that first kiss, these types are much more likely than other subjects to change their minds about a potential partner, researchers found. If it’s not in his kiss, forget about him.
But other people might use different criteria to size up their mates:
- men
- those who rate themselves as less sexually attractive, and
- people looking for commitment.
In the grand search for a partner, these individuals screen for people who seem to have the inclination and resources for the long haul. For these groups, kissing has a lower priority at the beginning of dating.
Among the study’s participants who said they were in exclusive relationships, frequency of kissing, rather than of sexual intercourse, was best correlated with relationship happiness.
“You would think that intercourse would be even more bonding, more intimate, but that’s not necessarily so,” Rafael said. “Maybe you have a happy relationship and you don’t need more intercourse.” For contented couples, he said, kissing continued to be a conveyor of emotion.
“In choosing partners, we have to deal with the ‘Jane Austen problem’: how long do you wait for Mr Darcy to come along when you can't wait forever and there may be lots of you waiting just for him? At what point do you have to compromise for the curate?” asks Professor Robin Dunbar of Oxford University.
“What Jane Austen realised is that people are extremely good at assessing where they are in the ‘mating market’ and pitch their demands accordingly. It depends what kind of poker hand you've been dealt. If you have a strong bidding hand, you can afford to be much more demanding and choosy when it comes to prospective mates.
“We see some of that coming out in the results of our survey, suggesting that kissing plays a role in assessing a potential partner,” Professor Dunbar explained.
While high levels of arousal might be a consequence of kissing (particularly as a prelude to sex), the researchers say it does not appear to be a driving factor that explains why we kiss in romantic relationships.
In a companion paper in the journal Human Nature, the researchers report that women's attitudes to romantic kissing also depend on where in their menstrual cycle and their relationship they are. Women valued kissing most at initial stages of a relationship when they were in the part of their cycle when they are most likely to conceive. Previous studies have shown that hormonal changes associated with the menstrual cycle can change a woman's preferences for a potential mate. When chances of conceiving are highest, women seem to prefer men who display supposed signals of underlying genetic fitness, such as masculinised faces, facial symmetry, social dominance and genetic compatibility.
It appears that kissing a romantic potential partner at this time helps women assess the genetic quality of a potential mate, the researchers say.
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And here's what Cher had to say about all this!