The Territorial Imperative  The Territorial Imperative: A Personal Inquiry Into the Animal Origins of Property and Nations is a 1966 nonfiction book by American writer Robert Ardrey. It describes the evolutionarily determined instinct among humans toward territoriality and the implications of this territoriality in human meta-phenomena such as property ownership and nation building. "The Territorial Imperative" was an immediate success and remains a widely influential work of popular science. It extended Ardrey's groundbreaking anthropological work, contributed to the development of the science of ethology, and encouraged an increasing public interest in human origins. "The Territorial Imperative" is the second book in Ardrey's Nature of Man Series; it is preceded by "African Genesis" (1961) and followed by "The Social Contract" (1970) and "The Hunting Hypothesis" (1976). It was illustrated by Ardrey's wife, the South African actress and illustrator Berdine Ardrey (née Grunewald). Ardrey dedicated "The Territorial Imperative" to Henry Eliot Howard, who was noted for being one of the first to describe in detail the territorial behaviors of birds. "The Territorial Imperative" develops the theses originally introduced in "African Genesis: A Personal Investigation into the Animal Origins and Nature of Man", which was published five years earlier. In "African Genesis", Ardrey posited that man originated in Africa instead of Asia, that he is driven by inherited instincts to acquire land and defend territory, and that the development of weapons was a fundamental turning point in his evolution. "The Territorial Imperative" further explores these ideas with a special emphasis on man's distinct preoccupation with the concept of territory. It goes on to elucidate the role that inherited evolutionary instinct, particularly the so-called "territorial imperative", plays in modern human society in phenomena such as property ownership and nation building. "The Territorial Imperative" caused significant scientific and popular controversy. In it Ardrey restated and developed his challenge to the reigning methodological assumption of the social sciences, that human behavior is fundamentally distinct from animal behavior. As he writes in "The Territorial Imperative", "The dog barking at you from behind his master’s fence acts for a motive indistinguishable from that of his master when the fence was built." Robert Wokler wrote of Ardrey's challenge to the established life sciences: What ought to be studied, according to Ardrey, are the relations between individuals that stem from the innate and universal attributes of animal life, whereas cultural anthropologists who detect a fundamental discontinuity between mankind and other zoological species are just impervious to the revolutionary ideas of Darwinism which have reverberated throughout all the life sciences apart from their own.