 Anthropologists are divided into two schools on the origins of kissing, one believing that it is instinctual and intuitive, having evolved from activities like suckling, premastication, or checking the health of a potential mate via inspecting their saliva, and the other believing that it is a learned behavior, spread by European explorers.The earliest reference to kissing-like behavior comes from the Vedas, Sanskrit scriptures that informed Hinduism, Buddhism and Jainism, around 3,500 years ago, according to Vaughn Bryant, an anthropologist at Texas A&M University who specializes in the history of the kiss.Both lip and tongue kissing are mentioned in Sumerian poetry