Psychology and Population is defined as the study of individual dispositions and behavior that affect the size, structure and dispersion of the population, and the way in which acts of individuals enter into the dynamics of population change. Even this definition was viewed as inadequate, ignoring, as it does, the reciprocal effect of population on individuals. The author proposes a framework of relationships between the individual and society. Within this framework, he focuses on the causes of human fertility, which refers to the number of live births in a population, not to the capacity to bear children. The urgency of the population problem is stressed as the factor which should motivate psychologists to assist in researching the myriad questions which a focus on Psychology and Population raises. Many of these questions are included, and significant research beginnings cited. (TL)