This paper examines the assertion that a genetically programmed instinct referred to as the agrarian imperative underlies a territorial drive that compels farmers and their biological heirs to hang on to their land at all costs while working hard, taking risks, enduring pain, and hardship. Research from multiple fields refutes the assumption. Basic physiologic instincts are not primary drivers of animal or human behavior. Their expression is greatly modified by the physical and social environments in which animals mature and learn. The human cerebral cortex with forethought and reflection greatly modifies basic instinctual drives. As a result, human behavior is to a large degree self-reflective and self-determined within the limits of the opportunities and resources available to individuals. The primary factors involved in continued successful farm operations across generations are not genetic, but rather farmers' access to economic, cultural, and social capital resources. These forms of capital and their distribution explain the evolution of human societies from preagricultural hunter-gather tribes to agrarian family kinship groups to complex nation states. Current highly mechanized, large-scale agricultural production focused on a few genetic strains of plants and animals provides abundant food at low cost, but is vulnerable to man-made and natural pandemics of human, animal, and plant pathogens as well as to disasters that can destroy the infrastructure required to support the system. A critical agrarian imperative is to ensure in perpetuity a pool of small farm operators capable of using simple farming technology for raising multiple cultivars and species of plants and animals.