I am hoping to learn the population standard deviation for the AS quotient. No luck so far, but this paper has the following info: 100 people suspected of having Asperger's took the test, and then were evaluated by two clinicians using the DSM-IV criteria. The 73 subsequently diagnosed with Asperger's had a mean of 36.62 and std. dev. of 6.63. The 27 not diagnosed had a mean of 26.22 and std. dev. of 9.39. Needless to say, one should interpret these numbers carefully because of the selection into the study, and due to variation across clinicians in coming to the same diagnosis.