If you've ever been swept off your feet by a breathtaking first kiss, chances are you and your partner were tilting heads to the right. Why to the right? Because as many as 66 percent of kissing couples tilt the same righthand direction—theoretically a behavior influenced by our tendency to tilt right when in the womb. Combine that with the fact our brain can transmit special neurons to help us locate lips in the dark, and you can see why couples generally don't kiss with their eyes wide open. And that feeling often described as chemistry, or "sparks flying," is actually your brain opening the dopamine flood gates—a naturally occurring chemical that signals pleasure, excitement and energy making it hard to sleep and keeping you craving more. In fact, men who kiss their spouse in the morning everyday tend to live up to five years longer than those who don't. Add in the workout your main kissing muscle gets— the orbicularis oris—with the other 145 muscles and you can burn 6.4 calories per minute of kissing passionately. As we can see, smooching has its perks.
Like most things in life, kissing is not as cut-and-dry as we probably think. The physical, physiological, emotional, social and cultural influence behind one of our favorite romantic hobbies is deep and complex, with a surprising number of health benefits. Pucker up and learn more about the art of kissing—a small action with big science.