Subtitled "An introduction to human ecology," this work attempts systematically to treat "least effort" (and its derivatives) as the principle underlying a multiplicity of individual and collective behaviors, variously but regularly distributed. The general orientation is quantitative, and the principle is widely interpreted and applied. After a brief elaboration of principles and a brief summary of pertinent studies (mostly in psychology), Part One (Language and the structure of the personality) develops 8 chapters on its theme, ranging from regularities within language per se to material on individual psychology. Part Two (Human relations: a case of intraspecies balance) contains chapters on "The economy of geography," "Intranational and international cooperation and conflict," "The distribution of economic power and social status," and "Prestige values and cultural vogues"—all developed in terms of the central theme. 20 pages of references with some annotation, keyed to the index. (PsycINFO Database Record (c) 2012 APA, all rights reserved)