"Neurodiversity is a viewpoint that brain differences are normal, rather than deficits" (Understood.org).
Neurodiversity is the idea that differences in cognition don't indicate a problem or weakness that needs to be fixed or cured. Instead, it promotes the concept that all variations in the human brain are normal and bring both benefits and challenges. It suggests that everyone connects to and processes the world in their own way and that there is no optimal way to do this.
The term neurodiversity is attributed to Judy Singer, an Australian sociologist, who is known for describing herself as "likely somewhere on the autistic spectrum" (Spectrum Suite). She used it to promote inclusion and equality of all people. During the 1990's, the neurodiversity movement first appeared. From there, the word increased in popularity after being used in a 1998 issue of The Atlantic, which stated that:
“Neurodiversity may be every bit as crucial for the human race as biodiversity is for life in general. Who can say what form of wiring will prove best at any given moment? Cybernetics and computer culture, for example, may favor a somewhat autistic cast of mind”
(Spectrum Suite).
There are different opinions on the neurodiversity model. Some feel that it is between a strong social model and a strong medical model. Others have concerns about how it is defined, as they worry that it risks downplaying the suffering some people endure. Ari Ne'eman, autistic self-advocate and researcher, suggests a trait-based approach. Here, she proposes that a neurodiversity approach would be used for supporting non-harmful traits (eg. intense interests, stimming) and a medical model for traits which the individual is finding harmful.
The use of language is often central during discussions about neurodiversity. Originally, terms were created by medical professional or those outside of the communities they are discussing. Recently, this has changed and many communities are now explaining their preferences. However, it must be taken into account that, as in any community, everyone has individual preferences and these need to be respected.
The main debate is currently around person-first or identity-first language. Person-first language is where the person is put before the diagnosis, e.g., person with autism. Identity-first language is where the person's diagnosis or identity is put first, e.g. autistic person
Surveys suggest that many people prefer identity-first language as they feel that their diagnosis is a important part of who they are.
References:
https://www.understood.org/en/articles/neurodiversity-what-you-need-to-know
https://www.health.harvard.edu/blog/what-is-neurodiversity-202111232645
https://www.donaldsons.org.uk/news/the-language-of-neurodiversity/
https://www.verywellmind.com/should-you-say-person-with-autism-or-autistic-person-5235429