The Evolutionary Biology of Ourselves: Unit Requirements and Organizational Change in United States History

Abstract

Researchers have proposed that the distinction between so-called "simple" and "complex" societies can be expressed by an increase in the number of levels at which functional organization, interaction, and thus selection, operate. In spite of the obvious links between this suggestion and research into complex social organization amongst insects and other social animals, the levels of selection model has seen little use among anthropologists. We suggest that the primary reason for lack of research into the evolutionary causes of social complexity has been the lack of descriptive units with which we can examine phenotypic variation and heritability of social organization above the level of the organism. The goal of our paper, therefore, is to begin constructing descriptive units which map to meaningful models of multi-level selection. In order to demonstrate how these units are useful in a real dataset, we examine the functional changes involved in the United States economy over the last 100 years, a period of time characterized, we believe, by significant changes in the number and kinds of social aggregates functioning as "individuals" with respect to selection. Our preliminary analysis suggests that it is possible to measure changes in the scale at which functional integration occurs through published data, and that the multilevel selection model for complex society may possess considerable power for describing how selection of culturally transmitted variation occurs in complex societies.