Clinical, animal, and genetic evidence points to a role for the hormone oxytocin in autism and suggests that oxytocin-related abnormalities may be present in relatives of people with autism. Cholesterol may be similarly linked to ASD. This study will examine the levels of oxytocin and cholesterol in blood samples from 30 families that have at least one member with ASD and compare them to samples from families without autistic family members. Additionally, potential connections between both oxytocin and cholesterol and distinct behavioral and cognitive traits will be explored. Such links between genes and behavioral symptoms are called endophenotypes. Establishing endophenotypes will enable classification of subgroups within autism families that can aid the search for associated genes through molecular genetics studies.