An Indian judge ordered the arrest of actors Richard Gere and Shilpa Shetty over a kiss. (STRDEL/AFP/Getty Images)
Why humans kiss
Last Updated April 26, 2007
An itchy nose probably doesn't mean you are about to kiss a fool. That's just an old saying. But one study did find that, on average, a woman kisses 79 men before finding a husband.
In a lifetime, some people probably spend about the same time kissing as brushing their teeth. Not surprising then that anthropologists suspect smooching is embedded in human nature. In fact, some researchers have determined that the brain has evolved its own special way for detecting a partner's lips when the lights are out.
Primatologist Jane Goodall kissing chimpanzee (Jean-Marc Bouju/ AP Photo)
"We've probably been kissing since the dawn of time," explains Kathryn Denning, a York University anthropology professor. "We know that chimpanzees kiss today, so we can assume our very ancient pre-human ancestors kissed as well."
With primates being close relatives to humans, it's safe to say sharing a peck is part of our lineage. Like people, primates don't just nuzzle or sniff, but kiss mouth to mouth. Chimpanzees, and particularly bonobos, exchange big wet kisses when they greet and leave each other. Their ritual is so analogous to the human one that they even kiss to make up after a fight.
Similarly, human kissing can be a relationship barometer. The British Marriage Guidance Bureau found that married couples on the verge of a split kissed less often. They were also more likely to have intercourse than to kiss — an indication the venerable lip-lock might be the most intimate of relationship acts.
So, how did kissing evolve? One anthropological theory pegs it to a mother's mastication of food. Before the invention of processed baby food, mothers would chew food before passing it by mouth to their babies. Some cultures still use this practice, essential during the time after breastfeeding and before a baby cuts teeth.
Anthropologists also think kissing might originate from nuzzling and licking, the same way a dog licks her puppies after birth.
Madonna and Britney Spears 2003 MTV Awards staged kiss (Julie Jacobson/AP Photo)
On the other hand, it just may be linked to our poor sense of smell. What a dog's keen scent detects in a few social sniffs, is next to impossible for a human to sense. People need to get up close and personal to recognize pheromones, the intimate chemicals that some say help in partner selection.
Denning speculates kissing has a long history because people enjoy it. "There are a lot of nerve endings in the lips," she notes, "so it feels good."
A kiss also releases endorphins in the brain that help relieve stress and even depression. During a typical smack, hearts can race to 100 beats a minute, blood pressure jumps, pupils dilate, lips swell and skin blushes.
Cultural and religious differences
While kissing is mostly about intimacy and love, it's also symbolically tied to friendship and respect within cultures and religions, which is the problem actor Richard Gere found himself in when he swept Bollywood actress Shilpa Shetty into his arms in Delhi recently.
Some Hindus, including an Indian judge, labelled the televised kiss an act of indecency for its public display of affection. But that shouldn't suggest kissing isn't part of Indian culture. In fact, in 1500 BC, Indians were the first to document the kiss. Four Sanskrit texts recorded nose rubbing as a lovers' gesture.
Kissing might stem from animal behavior.
Then there's the Kama Sutra. By the 6th century AD, the erotic text instructed on three types of kisses, including "touching kissing," to be performed with the tongue.
About 90 percent of the world's cultures engage in the lip variety — but very differently.
"Heterosexual men in America don't usually kiss each other, but it's the norm in parts of Europe, the Middle East and Africa," says Denning. "In contrast, male and female acquaintances might kiss on the cheek in North America, but this is a grave social offense in some other areas of the world."
From culture to culture, knowing how and when to pucker up can mean the difference between rejection and inclusion. To the Inuit, smell kissing, by rubbing noses, is customary. Certain African tribes literally kiss the ground walked on by their leaders.
In Victorian times, it was the rule in the better social strata for a man to kiss a woman on the hand when greeting. In rural Romania by contrast, a woman today will kiss a strange man's hand as a sign of respect. (Romanians find it rude the other way around.)
Kris Kristofferson and Barbra Streisand in A Star is Born movie poster (Warner Bros./ Getty Images)
As of the 1700s, one of the few cultures not kissing were the people on the South Pacific island of Mangia. They had no knowledge of it before Europeans arrived.
Some places even condemn kissing. In 2005, a proposed Indonesian law would punish a public kiss with a jail sentence or fine. Also, it's only been recently that reserved China and Japan have begun shedding the notion that a public peck is uncouth.
Antiquated kissing laws are still on the books in some American states. A husband can't kiss his wife on Sundays in Hartford, Connecticut, and kissing a stranger is illegal in Cedar Rapids, Iowa.
The ritual also has religious connotations. In his book Kissing Christians, author Michael Philip Penn explains that, for early Christians, kissing set group boundaries and emphasized a familial relationship between members of the church.
Historically, Christians didn't kiss outside of their religion — they refused to kiss pagans or heretics. Penn also notes that Jews didn't have to kiss as part of their religion.
'Definitely an acceptance thing'
Mary Astor holds record for most kisses in a movie (127) (Hulton Archive/Getty Images)
Psychologists have long associated kissing with acceptance. A Toronto artist tested the limits of this idea when he set about to kiss 100 women in four months as part of an art project. His goal was to experiment with his own social boundaries.
"Before that I was a shy person with girls, and pretty conservative," explains Tim McCready. "Getting somebody to kiss me was definitely an acceptance thing. I'd think, 'Can I get this girl to kiss me?' And the results were surprising."
Kissing close to 130 women, McCready found most women were quite willing to participate, especially once they found out it was for art. The idea was controversial to some, he says, while others found it to be funny and smart.
And what did he learn most about human nature through this experiment? Well, he says, "Kissing is more social than sexual, and it doesn't necessarily mean anything."