Social Influence and the Autism Epidemic - Incite at Columbia University

Despite a plethora of studies, we do not know why autism incidence has increased rapidly over the past two decades. This study shows that the rising prevalence, at least in part, is caused by the diffusion of information about the condition. Using California data, we found that children living very close to a child with autism are more likely to be diagnosed with autism. The result is explained by the social interactions between parents. A series of tests rule out competing explanations such as environmental toxicants, viral transmission, or the tendency for families of similar economic or demographic background to choose to live in the same type of neighborhood.