uta frith is a wonderful person and one of the most profound students in autism. she was one of the pioneers in developing the theory of mind, and pointing out how this is really the defining feature of it. she not only characterized it in psychological terms but she also began to study the biology of it and she's going to describe the difference between the social network in normal kids and kids with theory of mind, and the genetics of the disease which matthew state is going to describe, is really quite fascinating. because several new insights into human genetics emerged just as the genetics of autism was being explored. and they reinforced each other. and we're going to learn a lot about normal human genetics as a result of the study of autism. >> rose: gerald, tell me more about defining, having to understand the biology and the incident of autism. >> charlie, i actual oly have just a very little bit to add to eric's wonderful introduction. this syndrome, the core of it i believe is, and many people would agree, is the sense of aloneness, of living in isolati