Research in Dr. Strauss' lab has shown that people with autism may have difficulty with categorization. Categorization is an important cognitive skill that significantly reduces demands on memory. It is also critical to language development, and most theories assume an ability to categorize is a prerequisite for learning words. Deficient categorization skills would have a profound effect on how one learns about the world and ultimately acquires expertise about objects, social information such as people and faces, and language. Thus, deficits or differences in categorization may underlie the symptoms of autism. This project will examine the categorization abilities of infants at-risk for autism. Dr. Strauss' fellow will study infants that have an older sibling with autism. Specifically, the fellow will focus on the attentional, perceptual, and memory abilities of these infants especially as they relate to categorical knowledge of objects and people. The study will also track the development of these skills by following the same infants for the first two years of life. What this means for people with autism: Deficits in categorization skills may be a sign of autism, and they might be present as early as infancy. If so, this deficit could be used as an early diagnosis tool, and suggests new behavioral treatments geared toward enhancing categorization skills.