title: Social interaction behaviors discriminate young children with autism and Williams syndrome.
abstract: OBJECTIVE
  Autistic disorder (AD) and Williams syndrome (WS) are neurodevelopmental disorders characterized by contrasting abnormal social behavior (the former, socially avoidant; the latter, outwardly social); nonetheless, there are individuals with WS who display some behaviors that are characteristic of AD. We quantified the extent to which autism spectrum disorder (ASD) behaviors were present in children with WS.
  
  
  METHODS
  Twenty children with WS (27-58 months) and 26 age- and IQ-equivalent children with AD were administered the Autism Diagnostic Observation Schedule (ADOS). ADOS behaviors were compared between groups.
  
  
  RESULTS
  Two children with WS met DSM-IV criteria for AD, one of whom was also classified as having AD by the ADOS algorithm. Discriminant analysis of ADOS behaviors indicated that gesture, showing, and quality of social overtures best discriminated the groups.
  
  
  CONCLUSIONS
  Although some children with WS demonstrated some ASD behaviors, and a minority of children with WS had coexisting AD, the symptom profile in WS was different from AD. Despite some deficits in communication behaviors, showing, and initiating joint attention, children with WS made social overtures and efforts to engage others, whereas children with AD tended not to do so.
authors.affiliation: Dr. Lincoln, Ms. Searcy, and Dr. Jones are with the Salk Institute for Biological Studies Laboratory for Cognitive Neuroscience; Dr. Lincoln is also with Alliant International University, California School of Professional Psychology-San Diego; and Dr. Lord is with University of Michigan. Electronic address: alincoln@alliant.edu.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Lincoln
authors.affiliation: Dr. Lincoln, Ms. Searcy, and Dr. Jones are with the Salk Institute for Biological Studies Laboratory for Cognitive Neuroscience; Dr. Lincoln is also with Alliant International University, California School of Professional Psychology-San Diego; and Dr. Lord is with University of Michigan.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Searcy
authors.affiliation: Dr. Lincoln, Ms. Searcy, and Dr. Jones are with the Salk Institute for Biological Studies Laboratory for Cognitive Neuroscience; Dr. Lincoln is also with Alliant International University, California School of Professional Psychology-San Diego; and Dr. Lord is with University of Michigan.
authors.forename: Wendy
authors.initials: W
authors.lastname: Jones
authors.affiliation: Dr. Lincoln, Ms. Searcy, and Dr. Jones are with the Salk Institute for Biological Studies Laboratory for Cognitive Neuroscience; Dr. Lincoln is also with Alliant International University, California School of Professional Psychology-San Diego; and Dr. Lord is with University of Michigan.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lord
mesh_terms: D000465:Algorithms; D001321:Autistic Disorder / Q000175:diagnosis* / Q000523:psychology*; D002675:Child, Preschool; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D012919:Social Behavior; D018980:Williams Syndrome / Q000175:diagnosis* / Q000523:psychology*