Smooching, snogging, sucking face, swapping spit, tonsil matter what the alias, kissing is universally recognized as a sign of affection.  And just in time for Valentine's Day, exposes all including how to get (and give) a perfect pucker, key muscles, other biological stuff related to kissing and even a glimpse at the strange stuff we smooch, like the Blarney Stone.  

If your current status is "single," you'll still want to take the ultimate kissing quiz so you'll be relationship ready next time Cupid draws his bow.  If you're already in love, consider these tidbits as tools you can learn and put into practice together.

Scientifically speaking, anthropologists estimate that 90 percent of the people in the world kiss. It seems that kissing is as much a part of being human as flirting and the chemistry behind microexpressions.  HowStuffWorks explores these universal human traits from every angle in the quest to uncover why we kiss.  Here are a few theories:

  • For Food: Some anthropologists think kissing might have originated with human mothers feeding their babies much the way birds do. 
  • As Instinct: Other researchers believe primates that kiss, like the Bonobo apes, prove the desire to kiss is instinctive.  These apes actually kiss to relieve tension after disputes! 
  • To Find the Right Mate: Researchers have proven that women prefer men with immune system proteins that are different from their own. In theory, having a baby with someone with different immune proteins can lead to healthier offspring. 
  • To Achieve Euphoria: When you kiss, your brain responds by ordering your body to produce oxytocin, dopamine, serotonin and adrenaline. Along with natural endorphins, these chemicals produce the euphoria most people feel during a good kiss.

 "Kissing is so ingrained in our Western culture, that we all grow up thinking fondly about it, and often dream of our first romantic kiss," says Cristen Conger, host of the popular podcast, Stuff Mom Never Told You. "It's true," echoes podcast co-host and health writer, Molly Edmonds, "Even in today's germ-phobic society, kissing remains standard practice for anyone in love."