In this paper, we proposed the idea of "Operant Life" as a new viewpoint for the psychological study of individual behavior in every day life situation. The main points of the proposal were as follows. 1) From the viewpoint of operant life, the aim of psychological study of individual behavior is to answer the question, "Why does the individual organism do as it does ?" by identifying the controlling variables in its environment. 2) We adopt the fundamental concepts from the experimental analysis of behavior (TEAB) initiated by B. F. Skinner. 3) We classify individual behavior into three categories, namely (1) respondent behavior, (2) instinctive behavior and (3) operant behavior, emphasizing the importance of the last one. 4) In our opinion, TEAB has at least two weak points. One is the elementalism and the other is so to speak universalism. TEAB ignores the dynamic interaction among operants and species-speciality of individual organism. In contrast with TEAB, operant life makes much of the wholeness and uniqueness of individual organism. 5) We define "culture" as the common mode of operant behavior in a given group inherited from generation to generation through environmental route contrasting with the common mode of respondent and instinctive behavior which is inherited through the genetic route. 6) Operant life seeks to develop new methods to uncover the controlling variables of individual behavior, which is not free from genetic and socio-cultural constraints. For this purpose, operant life extends observational time, space, and social factors as possible controlling variables for their own sake.