The areas of difficulty (usually called the triad of impairments), is (a) speech (any language delays or disorders), (b) social interaction (problems with interacting with peers, appears to not know how to play or join in), and (c) rigid repeitive behaviours, lack of imagination, need for routines etc (this can show itself
in demanding things are always done
in the same way, throwing tantrums at changes
in routine, not appearing to have flexibility of thought etc).