Why functional assessment is enough: a response to Reiss and Havercamp.

Reiss and Havercamp (1997) recently suggested that sensitivity theory offers a basis from which to assess and treat challenging behavior exhibited by people with developmental disabilities. They contended that this approach would lead to more effective and durable interventions than would reliance on functional assessment. We respond to their claim that functional assessment is "not enough." After briefly reviewing and critiquing sensitivity theory, we outline the basic tenets of behavior analysis and describe literature on the development and use of functional assessment methodologies with individuals with developmental disabilities exhibiting challenging behavior, responding to several of Reiss and Havercamp's comments about the utility of this approach. Finally, we discuss several limitations of behavior analysis and functional assessment, providing examples of how these limitations are being addressed.