Ah, the romance of the New Year's Eve kiss—the flushed cheeks, the quickened pulse ... the stream of bio-data rushing to the somatosensory cortex? A research scientist deconstructs the kiss in the Washington Post, explaining that there's a lot going on with all five senses during a seemingly simple lip-lock. For example: "A long open-mouthed exchange allows us to sample another person's taste, which can reveal clues about his or her health and fertility," writes Sheril Kirshenbaum .
"Our tongues—covered with little bumps called papillae that feature our 9,000 to 10,000 taste buds—are ideally designed to gather such information." And because kissing requires close proximity, "our noses can detect valuable information about another person's health and perhaps even his or her DNA." All this and much more happens on a "subconscious level," and if a kiss flops, it may be the body's way of warning against a bad match. "If the chemistry is wrong, there's not much you can do," writes Kirshenbaum. "But take heart. Valentine's Day is less than two months away." (Read more kissing stories.)