Roy Richard Grinker started his training in psychiatry before he hit puberty, listening to his grandfather discuss the field. Later, Grinker rejected the idea of studying science, eventually settling into his current job as a professor of anthropology at George Washington University. But the academic wanderings over the years have brought him right back home in his most recent project, which marries anthropology with psychiatry in an attempt to make sense of an intensely personal issue: his own daughter's autism. In this article, Mr. Grinker discusses his new book "Unstrange Minds: Remapping the World of Autism" (Basic Books), wherein he analyzes how psychiatric understanding of autism has changed over the decades and how those shifts have influenced society. Drawing on his experiences with his daughter and some of the lessons he learned from his childhood education in psychiatry, he argues that the current autism epidemic is actually an illusion brought on by the broadening scope of an autism diagnosis and the fact that American society is more willing now than before to pay attention to autism and other mental disorders.