Theories and measurement of adaptive behavior

In this chapter we will briefly present an overview of the history and evolution of the construct of adaptive behavior. We will discuss its role and relevance in the field of disabilities with a special emphasis on intellectual and developmental disabilities (IDD). We will focus on the role of adaptive behavior regarding the diagnosis, classification, and as an intervention outcome of different IDD conditions, including intellectual disability (ID) and autism spectrum disorder (ASD). We will also present an overview of the best practices in conducting an evaluation of a person’s adaptive behavior (also called adaptive functioning; American Psychiatric Association, 2013) as well as presenting the characteristics and psychometric properties of some of the major assessment instruments. Lastly, we will review and discuss the use of the adaptive behavior construct and measurement internationally.