Decision Theory as a Branch of Evolutionary Theory
Abstract
This article examines the possibility that the theory of rational choice under uncertainty, including cognate theories of utility and subjective probability, may ultimately be reducible to a basis of evolutionary theory. As preliminary support for this reducibility hypothesis, L. Savage's classic axiomatization of decision theory, utility, and personal probability is derived mathematically from a simple biological population process model. The derivation establishes that the evolutionary constraint of fitness maximization imposed on organismic behavior by the action of natural selection can give rise to formal consequences comparable to the standard laws of rational choice, utility, and personal probability. If the logic of decision is ultimately biological, as the reducibility hypothesis suggests, profound changes may be called for in our perception of the character of rational judgment and in our methods of investigating it. Classical standards of rationality could no longer be regarded as absolute, behavior previously thought irrational might turn out to be biologically rational, and evolutionary process models would become potential psychological hypotheses concerning reasoned behavior.