Chris Oliver, Louisa Demetriades, and Scott HallUniversity of BirminghamAbstractAngelman syndrome is a neurogenetic disorder associated with unique behaviors and characteristics,including an unusually happy expression, inability to speak, ataxia, mental retardation,and abnormal EEG. Previous research has suggested that smiling and laughingbehaviors in Angelman syndrome are inappropriate, excessive, and dissociated from contextualevents. In the present study, the variability of smiling and laughing behaviors of 3individuals with Angelman syndrome was examined across typical social contexts. Resultsindicate that laughing and smiling increased during social situations and occurred at lowlevels during non-social situations. The behaviors, therefore, did not occur totally inappropriately,as has been suggested. The findings illustrate the need to divert attention tothe examination of environmental influences on purported phenotypic behavior in geneticsyndromes.