Reply #3: Presently, the distinction between autism and Asperger's rests on IQ subscores

[KamaAina]

I should know; I did the data analysis for the Yale field trial that got Asperger's included in DSM-IV for the first time.

IQ tests are divided into two parts: verbal ("A train leaves Boston going 30 miles per hour...") and nonverbal or performance (the block designs). By definition, a "neurotypical" subject will score within a few points on both, since that is how the tests are designed.

But in autism, the nonverbal score is significantly (>10 points) higher than the verbal score. In Asperger's, the reverse is true: the verbal score is elevated.

Clinicians encounter difficulty when they run into someone like me, both of whose subscores are off-scale. :P

edit: caps