On this Valentine's Day, you must read Joshua Foer's interesting and informative article on kissing:
Other species engage in behavior that looks an awful lot like the smooch (though without its erotic overtones), which implies that kissing might be just as animalistic an impulse as it sometimes feels. Snails caress each other with their antennae, birds touch beaks, and many mammals lick each other's snouts. Chimpanzees even give platonic pecks on the lips. But only humans and our lascivious primate cousins the bonobos engage in full-fledged tongue-on-tongue tonsil-hockey. [...]
If kissing is not universal, then someone must have invented it. Vaughn Bryant, an anthropologist at Texas A&M, has traced the first recorded kiss back to India, somewhere around 1500 B.C., when early Vedic scriptures start to mention people "sniffing" with their mouths, and later texts describe lovers "setting mouth to mouth." From there, he hypothesizes, the kiss spread westward when Alexander the Great conquered the Punjab in 326 B.C.
Happy Valentine's Day! Celebrate safely; stay away from Shiv Sainiks!