How Can So Little Brain Hold So Much Knowledge? Applicability of the Principle of Natural Selection to Mental Processes

Abstract

Though the principle of natural selection may seem somewhat implausible at first glance, it appears to be the only way to explain the occurrence of new organization in phylogeny, if one wishes to avoid appealing to homunculi, intelligent external agencies or other sources which already contain the organization. Similar considerations require that the principle be applied in understanding both the acquisition of new knowledge within the lifetime of individuals and also their use of old knowledge in new situations. To illustrate the possibility of applying the idea of natural selection to details of brain function and human thought, a model is presented in which mental structures consist of converging connections among sets of neural elements. A prominent feature of the model is that elements representing a cognition are retained in activated condition at one level of the system only following a sequence of random variations at other levels. Certain differences are noted between natural selection in phylogeny and natural selection in cognition. It is argued that such a model is necessary in order to deal with the problem of how unified perceptions and orderly acts can be accomplished in the face of the extreme variability of circumstance which the environment imposes. Both overt action and mental acts are hypothesized to involve random variations, selectively retained on the basis of information in perceptual cognitive structures. Arguments are then presented to suggest that a simple extrapolation of the method for handling perception would enable the model to explain some characteristics of abstract thinking. Finally, general considerations about how natural selection processes can lead to increased organization are used to support the idea that ontogeny of mental ability, as reflected in the model, takes place in stages. The end result is a system with intercommunicating levels that may be described as hierarchical, but without the usual connotations of strictness of hierarchical ordering.