Association for Behavior Analysis International

Organisms are selected based on what they can do, so behavior is fundamental at every level of selection, in the sense that anatomies and physiologies evolved in the service of behavior. We look at the founding selectionists, and then we examine selection as it operates in phylogeny (Darwinian evolution), ontogeny (operant behavior), and sociogeny (cultural selection, selection of verbal behavior). Selection as a causal mode differs fundamentally from classic causal modes (as in Aristotle's material, formal, efficient and final causes); it is not reducible to causal chains because, as in the three-term contingency in behavior analysis, it relates the outcomes of variations to their antecedent environments. The three levels of selection differ in what is selected and in mechanisms of selection, but it nevertheless remains appropriate to explore parallels among them. We consider some parallels, such as competing effects of short-term and long-term contingencies at each level of selection, and use them to interpret findings in sexual selection, evo-devo or evolutionary development, epigenesis, and horizontal gene transfer (among others), that have challenged the generality of Darwinian selection.

The target audience for the symposium is behavior analysts, graduate students, and post-docs who seek to learn more about the history and theory of selectionism as it relates to the three levels of selection highlighted by Skinner (e.g., 1981).

Darwin developed his theory of natural selection to account for the fact of evolution; he extended it from phylogeny to sociogeny when treating the evolution of human languages. Skinner discussed operant behavior as an ontogenic parallel and later included sociogenic selection as one of three varieties of selection by consequences; the sociogenic variety embraced both verbal behavior and cultural practices. Wilson, in his sociobiology, integrated phylogenic with sociogenic selection. In a little-known interaction, Wilson and Skinner discussed similarities between their approaches. We therefore cannot identify any one innovator with any particular level of selection, but we can explore their various contributions to each. As we shall show, each was a brilliant theorist, each was a consummate observer, and each was an incisive experimentalist. Their work, well-received by many, also aroused strong counter-reactions, most notably with accusations of fascism (e.g., Chomsky's attacks on Skinner; Gould's attacks on Wilson). The most prominent attacks on Darwin came not in his lifetime, but rather in the context of early twentieth-century social Darwinism, when natural selection was conflated with eugenics and racist theories. But in our behavior analytic environments selection thrives: within them it has been selected.

Variations provide the necessary substrates for both Darwinian evolution and Skinnerian shaping. When differential consequences (e.g., survival and procreation in one case; food or sex in the other) are based on individual members of the substrate, then new species or operant responses can emerge. Thus, for example, by reinforcing only the largest 20% of beak openings in a pigeon, one can shape a larger opening than was ever before observed. Importantly but less well appreciated, consequences also select the levels and characteristics of variability itself, e.g., variability of species phenotypes and response topographies. Darwin referred to selected variability as "divergent" and explained it by differential survival; in operant studies, it is referred to as "operant, or reinforced variability." Thus, just as the current size of beak openings is a function of past reinforcement, the current level of beak variability may be due to past variability-contingent consequences. I will provide some of the copious evidence for selection of levels and characteristics of variability in evolution and operant conditioning.I will also discuss how applications of reinforced variability can assist those involved in teaching and skills-training as well as in therapeutic situations, e.g., with behavior along the autism spectrum.