In Selection by Consequences, Skinner (1981) described a causal model that explains human behavior as a joint product of three levels of selection: (a) the contingencies of survival involved in natural selection, (b) the contingencies of reinforcement involved in the selection of individual behavior, and (c) contingencies of an evolving social environment. Since then, researchers from behavior analysis and other fields such as biology and anthropology have used an evolutionist/selectionist approach to greatly improve our understanding of those three levels of analysis. As our knowledge of each level has expanded, the borders between them and their belonging to specialized academic domains has become less clear. Even though Skinner (1981, p 502) stated that "each level of variation and selection has its own discipline-the first, biology; the second, psychology; and the third anthropology," we argue that Selection by Consequences sets a milieu for behavior analysis to take part in the analysis of the integrated relation among all levels of analysis. In this commentary to Skinner's (1981) paper, we aim to point out some advances in behavior analysis that may contribute to bridging the gap between the three levels of analysis described by Skinner. In doing so, we will briefly describe some relations between natural and behavioral selection and between behavioral and cultural selection. Additionally, we discuss an alternative model to analyze selection of cultures.
Natural-Behavioral SelectionLet us start with the relationship between natural and behavioral selection. Glenn and Madden (1995) pointed to Skinner (1953) andCampbell (1956) as the first to compare the processes of natural selection and reinforcement. Glenn and Madden argued that if the same processes that explain organic selection were applicable to behavioral selection, the understanding of one would provide valuable insights about the other. In organic evolution through natural selection, genes are the units of retention and replication that are transmitted generation-to-generation, enabling species survival and adaptation to environmental changes. On the other hand, in behavioral