The perception of a true increase in autism incidence is influenced by increased awareness, broader diagnostic criteria (e.g., including Asperger's into ASD), and the difficulty in sorting out genetic markers.

“i actually took it as uh i guess i took it as a given that there was a true increase in the incidence of autism though not as significant as what the perception is because this was also the perception is also being driven by as you say just a tremendous increase in awareness diagnostic criteria becoming broader uh more things being included right so for example what used to be called asperger's is now technically a part of asd right right but i guess the question is how would you ever sort it out that's the that's the other problem”