According to the Center for Disease Control and Prevention (CDC, 2013), developmental disabilities “are a group of conditions due to an impairment in physical, learning, language, or behavior areas. These conditions begin during the developmental period, may impact day-to-day functioning, and usually last throughout a person’s lifetime” (para. 1).

In some schools these terms are used interchangeably; however, there is a difference between them. Developmental disabilities encompass intellectual disabilities. That is, intellectual disabilities are considered a type of developmental disability, but developmental disabilities also include other disabilities that are fundamentally physical in nature, such as cerebral palsy (American Association on Intellectual and Developmental Disabilities [AAIDD], 2013).

Although these common definitions are used in diagnosing ID and DD, it is important to use these definitions with caution, as they provide only one perspective on such disabilities, mostly in line with a medical model perspective which tends to have its focus on impairments and treatment of the individual (Thomas, 2002). Although the medical model perspective has much to offer toward the health and well-being of individuals with disabilities, there is a push from a number of educational researchers to shift thinking about disability from a medical model to a social model. A social model of disability recognizes that while individuals may have impairments, it is society that needs to change, as society “creates” disability by denying those with disabilities equal participation in their communities (Couser, 2002). Kluth and Chandler-Olcott (2008) explain this notion in relation to individuals with autism:

Although many individuals with autism share that “it” is real—that they do experience things in different ways, that their bodies are uncooperative or that they have sensory or communication problems—many of these same individuals indicated that autism is, at least in moments, “created” by an inflexible society. Therefore, people may feel more or less challenged on any given day based on whether appropriate supports are provided for them or whether they are expected to communicate, behave, move, or interact in a conventional way. (p. 4)

Another point to consider is that there is wide variation among individuals with ID and DD. No label is ever sufficient to describe the intricacies, needs, abilities, or potentials of a human being. In fact, society has been wrong many times in its understanding of individuals with disabilities and assumptions about what they might be able to accomplish. As teachers, disability labels can help us consider some of the different needs our students may have; however, we should always take our understanding of our students from what they show us about themselves and what we are able to figure out from careful and flexible assessment of their needs, not just from textbook definitions of their disabilities.