When clinicians diagnose individuals with a mental disorder, they are making a statement about deviance, about what falls within and outside the range of normal mental states. Unfortunately, there are no clear categories, no bright lines separating normal from abnormal or uncommon. As the distinguished American psychologist William James noted, however, studying “the abnormal is the best way to understand the normal.” Let’s follow this logic. Consider the developmental disorder of autism. This disorder, typified by difficulties understanding what others believe and feel, ranges from individuals who appear locked out of the world, rocking back and forth to their own internal rhythm, to high functioning individuals such as Professor Temple Grandin, who not only teaches college-level courses, but has done wonders as a spokesperson for autism and for the animal welfare movement. This range already tells us that autism is represented by a spectrum, once identified by purely behavioral measures, but joined today by genetic and neurobiological markers. The genetic evidence is particularly helpful for explaining the observed variation. For example, the MAOA gene, located on the X chromosome, is involved in the regulation of social behavior and has different forms that map to differences in brain activity and stress physiology. The different forms correspond to the number of copies of the genetic material. This copy number is, in turn, partially responsible for the spectrum of autism observed, especially the degree of social dysfunction, including stress and aggression. Once we admit to a spectrum, and begin to pinpoint the factors that push individuals to stand on one end or the other, we must admit to admitting virtually everyone onto this spectrum. All of us, at some point in our life, have lacked sensitivity to the feelings and beliefs of others. All of us have been self-absorbed and locked out from the rest of the world. All of us have failed to express empathy and com