What’s the deal with kissing?
It would make sense for kissing to be favorable for evolution if it led to increased arousal and consequently a greater inclination to have sex. When a (heterosexual) couple is kissing, testosterone can pass from the man’s mouth to the woman’s, which may make her more receptive to sex (and the passing on of their genes). But it turns out that though people certainly kiss when they’re aroused, there’s not much evidence to suggest that it works the other way around, where kissing causes arousal. And though some other species such as bonobo monkeys also kiss, it doesn’t have quite the same association with sex as it does for other humans. This suggests that there are other factors at play than just the initiation of play time.
So can kissing help us figure out if we’ve found a potential mate? Some suggest that saliva can contain some clues about a person’s genetics, through taste, smell, or other biological cues, from which our brains can subconsciously derive meaning. It’s thought that swapping saliva can help two people determine how similar their immune systems are; The more different they are, the better, because it means any offspring they produce will have broader and more varied immune systems themselves.
But perhaps the most obvious benefit of kissing is in bonding and relationship building. A survey asking how much importance people place on kissing turned up some interesting trends: People who have many partners tend to rate kissing as more important at the beginning of a relationship, and especially right before sex. For these people kissing was less important during sex, even less important right afterward, and least important at other times not related to sexual activity. People in long-term relationships, however, rated kissing as equally important before sex and in other, more mundane situations. In fact, for people in long-term relationships, the frequency with which couples kiss seems to have more influence on their judgment of the quality of their relationship and their satisfaction with it than sex does.
In the end, it’s still not really clear what precisely has caused our species to love kissing, but it seems as though the practice is here to stay.
– Jaime Collins
Kissing helps us find the right partner — and keep them – Science Daily
The unromantic truth about why we kiss — to spread germs – The Daily Mail
SciShow — Why Do We Kiss? – YouTube
Vsauce — Why Do We Kiss? – YouTube
Dnews — Why Is Kissing So Much Fun? – YouTube