Neurodiversity is a broad theoretical and philosophical term, primarily referring to the idea that the human brain can function in a wide variety of ways in regard to key markers such as sociability, learning, and focus. According to neurodiversity, these differences in brain function are not necessarily harmful and should not be conceptualized according to binaries of "normal" and "pathological" function. Instead, it may be more helpful to simply see these functions as occupying a spectrum, where individuals can fall at different points without being classified as deviant or defective.
The notion of neurodiversity was developed in 1998 by the sociologist Judy Singer. The theory of neurodiversity is related to the social model of disability, which argues that disabilities are largely formed by the existence of societal barriers rather than objectively established according to divergences from normalized expectations. For example, a person with limited mobility does not need to inherently be considered disabled in contrast to someone with full mobility; they begin to experience disability when they encounter barriers such as buildings with steps and without ramps. The neurodiversity approach was first adopted and championed by advocates for the rights of individuals on the autism spectrum. Some advocates for other neurodevelopmental conditions, ranging from Tourette's, to schizophrenia, to obsessive-compulsive disorder, have also adopted the neurodiversity paradigm. Supporters of neurodiversity often find it empowering because it allows them to challenge the idea that there is something "wrong" with them and that they need to be fixed or cured. Neurodiversity also tends to be associated with greater demands for autonomy, disability rights, and support systems that enable full participation and function.
Some individuals are critical of the idea of neurodiversity because they believe that it privileges individuals with greater degrees of functionality and fails to account for individuals who experience more suffering or distress and might rightly view themselves as needing or wanting to be "cured."
In Simsion's novel, Don is never given a specific diagnosis, but it is strongly implied that he experiences some types of brain function that are distinctive from how the majority of the population functions. Don reflects that "I now believe that virtually all my problems could be attributed to my brain being configured differently from those of the majority of humans" (pg. 205). He does not think that there is anything wrong with him, and he is able to see the strengths that his particular brain function gives him. Don is able to live a happy and successful life without changing any of his predominant characteristics.
