Toth, Karen Elizabeth2009-10-062009-10-062007b58539463180722727Thesis 57396http://hdl.handle.net/1773/9024Thesis (Ph. D.)--University of Washington, 2007.Background. Studies are needed to better understand the broad autism phenotype in young siblings of children with autism, and to identify areas of impairment, so that interventions can begin at as young an age as possible. Method. Multiple measures were used to examine cognitive, adaptive, social communication, social-emotional functioning, imitation, play, and language abilities in 42 non-autistic siblings and 20 toddlers with no family history of autism, ages 18-27 months. Results. Siblings had lower mean receptive language and adaptive behavior skills, lower overall rates of social communication and social-emotional functioning, and used fewer words, distal gestures, responsive social smiles, and pointing during social interactions. Additionally, parents reported social impairments in siblings by 13 months of age. In other domains, such as imitation and play, siblings performed similarly to controls. Conclusions. These results suggest that certain aspects of language and social communication are affected at an early age in young non-autistic siblings. As such, the development of such children should be closely monitored by parents and professionals, with appropriate interventions implemented as needed.vi, 93 p.en-USCopyright is held by the individual authors.For information on access and permissions, please see http://digital.lib.washington.edu/rw-faq/rights.htmlTheses--PsychologyThesis