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 au

ces are beneficial, for what individuals and in what contexts, and through what specific mechanisms. Recent research has made it patently clear that William James (1890, p. 442, 2) underestimated the faculties of human infants when he suggested that their first sensory experiences were a “blooming, buzzing conf