ABSTRACT
Psychology.—In his pioneering work published in 1943, Leo Kanner isolated autism as a syndrome characterized by (1) the inability to establish socioaffective relations with others (→SOCIAL COGNITION), (2) mutism or the incapacity to use language for communicative purposes (→COMMUNICATION, LANGUAGE), and (3) abnormal responses to the environment (stereotypies, immutability)—all standing out against a normal physical appearance and isolated areas of competency. The symptomatology was later supplemented with another criterion: (4) the appearance of these signs before the age of thirty months. Despite general agreement on these four criteria, it is always difficult to establish an irrefutable diagnosis of autism. Mental deficiencies and other associated impairments, frequent but not necessarily present, are one of the reasons for this uncertainty, which is made worse by the fact that the criteria remained rather subjective for quite some time. Asperger’s syndrome, another form of autism isolated by Hans Asperger, involves socioaffective impairment associated with normal language development.
