Four motivational components of behavior

I have been interested in what motivates people for over 35 years. During this period of time, our understanding of the processes involved has increased dramatically. From my reading of the literature, it appears that there are four major components that act, and more importantly, interact, to produce motivated behavior. Motivated behavior is a dynamic, ever-changing product of these components and their interactions. The idea that motivation is dynamic and interactive has been proposed before. In his force field theory, Lewin (1936) proposed a dynamic view of behavior, and Birch, Atkinson and Bongort (1974) also conceived of behavior as a constant behavioral stream changed from one moment to the next by the conditions of the situation in which one finds herself/himself. However, while Lewin¿s model emphasized internal and external factors, and Birch et al. proposed cognition as the major source of behavior change, the present proposal suggests that motivated behavior results from a complex interplay between at least four currently identifiable components. Those four components are: biology, environment, cognition, and emotion. Each contributes to the production of behavior in its own unique way and, each can interact with one or more of the others to produce motivated behavior. While it is reasonable to assume that developmental changes across the lifespan would also influence motivational processes, the writer will leave it to others to examine those processes