A big question is whether kissing is learned or instinctual. Some say it is a learned behavior, dating back to the days of our early human ancestors. Back then, mothers may have chewed food and passed it from their mouths into those of their toothless infants. Even after babies cut their teeth, mothers would continue to press their lips against their toddlers’ cheeks to comfort them.
Anthropology doesn’t offer clear answer to the question, whether kissing is learned or instinctive. Yet many primates kiss in their own ways. Bonobos (Congo Chimpanzees or so called Pygmy Chimpanzees) use kissing to soothing tension among them. On the other hand many Eastern Asian cultures have traditionally found kissing repulsive practice.