Divergent predictions from behavioral momentum theory and 'diversity theory'

The development of basic behavior analysis research is sketched from its conceptual origins through the advent of behavioral momentum theory (BMT), which is described in some detail. An explanatory metaphor as an alternative to that of BMT is proposed, and the name "diversity theory" is given to the theoretical perspective based upon that new metaphor. Conceptualizations in diversity theory that lead to research expectations are explicated. The similarity of research interests between diversity theory and BMT is acknowledged, while their diverging predictions for research results are identified. Two experiments are reported, which examined resistance to change of variable-interval (VI) schedule responding in components of multiple schedules, and in which three disruptor operations were used: moderate pre-session feedings on successive days; huge-amount pre-session feedings on temporally dispersed days; and successive days of extinction. In Experiment 1, a two-component multiple VI VI schedule was employed throughout training and disruptor conditions. One component contained a concurrent VI 120-s VI 60-s schedule, while the other component contained a single VI 40-s schedule. The resistances to change of these pairs of schedule performances were compared: VI 120-s versus VI 60-s; combined VI 120-s and VI 60-s responding versus VI 40-s. Results were inconclusive due to a lack of systematic pattern of resistances to change of the compared performances. In Experiment 2, a three-component multiple VI 120-s VI 60-s VI 60-s schedule was employed during training conditions. During resistance-to-change test conditions a two-component schedule was used, as the VI 120-s and one VI 60-s schedule performance were adjoined into a concurrent VI 120-s VI 60-s schedule. This introduced to the newly-concurrent VI 120-s and VI 60-s schedule responding a basis for generalization decrements, and also for a phenomenon derived in diversity theory. Resistances to change of the three performances were compared in pair-wise fashion. The results generally exhibited a pattern to be expected from greater reinforcement of the VI 60-s schedules and generalization decrement effects. However, the effects were unreliable and the deviations from those expectations were consistent with countervailing effects predicted by diversity theory. Prospects for diversity theory are discussed.