The Science of Kissing

Can you read his lips? (Photo: ThinkStock)Pop quiz:  When was the last time you kissed — really kissed — your partner? If you just met, come up for air. If you’ve been together a while, you probably can’t remember. That’s because kissing evolved as a courtship tool to suss out a long-term mate, according to the results of a new study conducted by Oxford University.

“When two people kiss for the first time, they transmit signals about each other’s health and DNA through taste and smell, helping them best select a compatible partner,” study author Rafael Wlodarski, a DPhil student in the Department of Experimental Psychology at Oxford University, tells Yahoo Shine. “Once a couple has decided to stay together, kissing tends to die down because they no longer need that genetic information.”

Here’s how it works: When you’re super attracted to someone, his natural, unique scent smells intoxicating and you may find yourself deeply inhaling while you kiss. Digging each other’s scent means your bodies are subconsciously responding to each other’s genetic codes — a sign you’ll produce healthy offspring.

Sadly, when you’ve been in a relationship for a while, you may not kiss as passionately because you (and your body) know he’s “the one.” However, it's important to keep the passion going — the study also found that relationship satisfaction is linked to how frequently a couple locks lips, not how often they have sex. And you don’t have to make out each time in order to reap the benefits. “As long as the kiss is intimate with close facial proximity, that’s enough,” says Wlodarski.

A few suggested techniques: You can make your kisses count by using your hands (lightly tugging on each other's hair releases pleasure-inducing endorphins), popping a mint (the menthol produces a tingly warm and cool sensation), or gentle lip biting (variety keeps things interesting!).

However you do it, just keep kissing!