Professor David Skuse explains that the language and social difficulties associated with autism correlate more closely than repetitive behavior symptoms.

Now one of the questions that seems to me to be particularly interesting about the symptoms of people who suffer from autism is, to what degree do these symptoms cluster together and to what extend they can be found to a greater or lesser degree in people who aren’t typically autistic? Evidence that is emerging from work we have been doing over the last few years strongly strongly suggests, firstly, that the social and the language aspects of autistic symptomatology are very, very closely connected. So, it would be unusual to find somebody who had the social difficulties without the language problems and very unusual to find somebody who had the language problems without the social difficulties. They go together, they are almost part of the same thing. The repetitive and stereotype behaviors, resistance to change, the unwillingness to try new things, those symptoms seem to be less correlated, less closely associated, with the language and the social difficulties. We do find people who have what we call atypical autism - so autism that isn’t typical - who will have the social and language difficulties, but don’t have those motor behaviors, don’t have the flapping and the rocking, don’t have the resistance to change, don’t have the routines and those other features that are in the third part of the dimension, of the three dimensions, as you will, of autism.

symptoms of autism, social difficulties, symptomatology, diagnosis, autism