The number of autism spectrum disorders diagnoses in the U.S. has risen exponentially over the last 10 years. Why has this happened? This research project begins from the sense that the search for explanation has up till now been impeded by an untenable opposition between biological (therefore "real") and social (therefore "artificial") causes. Instead, it proposes to examine autism as a bio-social phenomenon, caused by complex feedback loops between, on the one hand, how we think about, classify, treat and institutionally process individuals with autism, and on the other hand, how these individuals react to their treatment. The main point is that we need to think differently about expertise. The biological approach thinks of expertise as describing and explaining the autism epidemic from the outside. The social approach thinks of expertise as "constructing" autism all by itself. But in the case of autism it is much more realistic to think of expertise as distributed in a network, since patients and parents have become "lay experts" with considerable input on how the disorder is viewed and treated. To study such complex networks and feedback loops, the researchers are conducting ethnographic participant observations in clinics and schools where diagnosis and treatment of autism takes place. The researchers also interview parents, patients, experts and advocates. The broader impact of the proposed activity would hopefully be a greater clarity of vision about the current epidemic of autism diagnoses and how to address it. Autism is likely to prove a major social problem in the future, and it is already changing the nature of schooling in the U.S. The main thrust of the proposed research is to highlight the extent to which what is at stake is neither simply a biological condition for which a cure may or may not be found, nor a social construction which can be dispatched by being unmasked, but a deep ethical and economic question about the criteria of membership in society, which in our era, more than any previous times, have become a matter of conscious human choice.