Rational choice and the structure of the environment

[H. A. Simon](https://en.wikipedia.org/wiki/Herbert_A._Simon), 'Rational choice and the structure of the environment', _Psychological Review_, vol. 63 (1956), pp. 129-38. https://doi.org/10.1037/h0042769 [[via Google Scholar](https://scholar.google.com/scholar?cluster=13954564762960950179) Snippets of text (from the beginning, maybe the middle, and the end) appear below, to give a sense of the content for the chapter. For more depth, the original source is cited, above. ---

... much attention has been focused on the characterization of _rational choice_, and because the latter topic has been a central concern in economics, the theory of decision making has become a natural meeting ground for psychological and economic theory. A comparative examination of the models of adaptive behavior employed in psychology (e.g. learning theories), and of the models of rational behavior employed in economics, shows that in almost all respects the latter postulate a much greater complexity in the choice mechanisms, and a much larger capacity in the organism for obtaining information and performing computations, than do the former. Moreover, in the limited range of situations where the predictions of the two theories have been compared (see 7, ch. 9, 10 and 18), the learning theories appear to account for the observed behavior rather better than do the theories of rational behavior. Both from these scanty data and from an examination of the postulates of the economic models it appears probable that, however adaptive the behavior of organisms in learning and choice situations, this adaptiveness falls far short of the ideal of 'maximizing' postulated in economic theory. Evidently, organisms adapt well enough to 'satisfice'; they do not, in general, 'optimize'. [p. 214] [....]

## The Environment of the Organism We consider first a simplified (perhaps 'simple-minded') organism that has a single need -- food -- and is capable of three kinds of activity : resting, exploration, and food getting. The precise nature of these activities will be explained later. The organism's life space may be described as a surface over which it can locomote. Most of the surface is perfectly bare, but at isolated, widely scattered points there are little heaps of food, each adequate for a meal. [p. 216] [....]

## Perceptual Powers, Storage Capacity, and Survival It is convenient to describe the organism's life space not as a continuous surface, but as a branching system of paths, like a maze, each branch point representing a choice point. We call the selection of a branch and locomotion to the next branch point a 'move'. [....] [p. 217] [....]

## Choice Mechanisms for Multiple Goals We consider now a more complex organism capable of searching for and responding to two or more kinds of goal objects. In doing this we could introduce any desired degree of complexity into the choice process; but the interesting problem is how to introduce multiple goals with a minimum complication of the process -- that is, to construct an organism capable of handling its decision problems with relatively primitive choice mechanisms. [p. 221] [....]

## Further Specification of the Environment : Clues In our discussion up to the present point, the range of the organism's anticipations of the future has been limited by the number of behavior alternatives available to it at each move (d), and the length of the 'vision ' (v). It is a simple matter to introduce into the model the consequences of several types of learning. An increase in the repertoire of behavior alternatives or in the length of vision can simply be represented by changes in d and v, respectively. [p. 224] [....]

## Concluding Comments on Multiple Goals The central problem of this paper has been to construct a simple mechanism of choice that would suffice for the behavior of an organism confronted with multiple goals. Since the organism, like those of the real world, has neither the senses nor the wits to discover an 'optimal' path - even assuming the concept of optimal to be clearly defined - we are concerned only with finding a choice mechanism that will lead it to pursue a 'satisficing' path, a path that will permit satisfaction at some specified level of all of its needs. [p. 226] [....]

## Conclusion In this paper I have attempted to identify some of the structural characteristics that are typical of the 'psychological' environments of organisms. We have seen that an organism in an environment with these characteristics requires only very simple perceptual and choice mechanisms to satisfy its several needs and to assure a high probability of its survival over extended periods of time. In particular, no 'utility function' needs to be postulated for the organism, nor does it require any elaborate procedure for calculating marginal rates of substitution among different wants. [p. 228] The analysis set forth here casts serious doubt on the usefulness of current economic and statistical theories of rational behavior as bases for explaining the characteristics of human and other organismic rationality. It suggests an alternative approach to the description of rational behavior that is more closely related to psychological theories of perception and cognition, and that is in closer agreement with the facts of behavior as observed in laboratory and field. [pp. 228-229]