We argue that the evolutionary process of neoteny -- the natural selection of regulatory gene mutations that retain a youthful ontogenetic system of physiological and behavioral characteristics, and thus never activates the full species-specific features of the ancestors’ adulthood. The resulting new behavio-morph retains infant/young features throughout ontogeny and never displays the adult behavior or physiology of the adult ancestor. This kind of neotenic adulthood defines the human character. We not only inherit our ancestors’ youthful anatomy and physiology but the ancestors’ youthful motivations and proclivities such as docility and social dependency, curiosity and learning as well. We retain our ancestors’ youthful small teeth, and we continue to play throughout adulthood. Like young, but unlike most adult mammals, humans continue throughout life to crave attention, play, learn and remain curious whether just for social gossip or for scientific research.