Behavioral momentum theory states that behavioral resistance to change is positively related to reinforcer rate and independent of response rate under most circumstances. We examined behavioral momentum in humans with developmental disabilities. The experimental procedures were implemented as a computer game. Different rates of positive reinforcement were programmed in two alternating components signaled by distinctive cues. For 10 participants who successfully completed testing, resistance to disruption by an alternate source of reinforcement was greater in the component with the higher reinforcer rate, although the magnitude of the difference varied among individuals. These results confirm reinforcer rate effects consistent with behavioral momentum under laboratory conditions and with the largest number of human beings with developmental disabilities studied to date.

Our laboratory is currently conducting studies of behavioral momentum in humans with mental retardation. A better understanding of momentum effects may contribute to more effective procedures for reducing or eliminating learning problems in this population (e.g., McIlvane & Dube, 2000). In our studies, we have occasionally encountered cases where even liberal baseline stability criteria were not met after a substantial number of sessions, and thus typical procedures for evaluating momentum were not appropriate. This brief report will describe an alternative testing procedure that we are examining for use in these situations.