The Functional Approach to Behavior: Is it Useful?

Abstract

Natural selection is an axiom for a functional approach to studying behavior. Research is thus canalized toward observing the function of behaviors in relation to an organism's reproduction and/or survival. Explanations resulting from this approach can be instructive only if all or most behaviors under study are the consequence of natural selection. This assumption has no empirical basis, however. Predictions derived from selection theory are supported generally, but these predictions are not unique to the selection process and are therefore ambiguous. Behaviors can be induced environmentally without a change in the genotype, and they can be learned and transmitted culturally as well as genetically; all three processes can relate to increased measures of fitness. Which of these processes has led to the establishment of a behavioral pattern is not easily discernible from simple observations. Behaviors are extremely plastic in their development, and thus studies that assume heritable variation should be viewed with caution. The relative significance of these factors is not known because of the artificial dichotomization of behavioral explanations into proximate and ultimate causation, the functional approach being the paradigm of the latter. Therefore, a functional approach limits our understanding of the origins, diversity, and persistence of behaviors. An epigenetic approach is proposed as being more useful because it yields a more comprehensive understanding of behavioral processes.