In the same way we all have different height, weight, hair colour, there is growing recognition for diversity in cognition. The range in neurological profiles is all part of the natural variation of humans, and there is a consistent prevalence of differences (for example, approx. 10% of the population can be expected to demonstrate dyslexia; 2% autism).
In terms of neurodiversity and how it is made up the work Mary Colley (referenced in the graphic below) offers a useful framework to better understand what the term ‘neurodiversity’ encompasses.
Psychometric tests normally take a minimum of 3-4 years to develop as it is essential that they can demonstrate legally defensible levels of reliability, sensitivity, validity and can demonstrate that adverse impact has been considered and mitigated during the construction of the test.