evel representational capacities that currently have evoked much interest in research (Loesche, 1990). Another possible cause is genetics. Autism almost certainly has a strong genetic basis. Among brothers and sisters of autistic persons, the rate of both autism itself and milder related symptoms is 50 to 100 times higher than average. The matching rate for autism in identical twins in 65-90%; for fraternal twins, it is close to the sibling average. A statewide survey undertaken in Utah in the 1980s found that among eleven families with an autistic father, more than half of the 44 children were autistic. According to some studies, many apparently normal parents of autistic children have undiagnosed mild autistic symptoms as well. Autism has not been linked to a specific mutation and probably lies at the end of many different genetic pathways (Ashby and Goodman, 1994). Due to the impossibility of obtaining autistic infants as research subjects, researchers have been seeking other methods to identify signs of vulnerability early in development. With the advent of affordable video technology, families in increasing numbers have home videos which inadvertently provide documentation of their childrens development. Retrospective video analysis has shown success as an ecologically valid methodological tool for earlier identification of children with various psychopathologies (Adrien et al., 1993, as cited in de Benedetti, 1993). Although a endless of methodological problems are encountered, retrospective video analysis currently appears to be an excellent option for accessing very early periods in development-months or years before a child with autism is diagnosed (de Benedetti, 1993).Several retrospective video studies conducted specifically in the autism realm suggest that young children with autism can be distinguished from typically developing children with respect to sensorimotor intelligence, orientation to social stimuli,...
