The science of kissing itself is called philematology. Philematophobia is the term for fear or hatred of kissing. Man's earliest kisses were delivered by the nose, similar to the kind of 'nuzzle-sniff' popular in Eskimo culture. Nose kisses were used to identify and reconnect with relatives and friends and even provide clues about a person's health. Kissing involves six major muscles around the mouth help to pucker up the upper lips, pull up the corners of the mouth, and pull down the lower lips. Kissing for one minute burns 26 calories. It's believed that about two-thirds of people tip their heads to the right while kissing. Scientists believe this preference starts when we tip our heads to the right in the womb.