Part 4 of a seven-part series asking whether the modern autism spectrum accurately describes the diversity of neurodivergent cognition. Has diagnostic simplification obscured meaningful neurological differences? Autism is now defined as a single spectrum in modern psychiatric manuals, replacing earlier distinctions such as Asperger’s syndrome. While this simplified diagnosis, it also collapsed multiple neurological profiles into one category. This article examines whether the spectrum model accurately reflects autistic diversity or obscures meaningful differences in cognition, support needs, and lived experience.