Knott et al., 1995); however, the results of these stud- ies suggest that children with developmental disabili- ties and their siblings show marked similarities in their interactions compared to normally developing sibling pairs. Children with disabilities such as Down syn- drome have been found to spend similar amounts of time interacting with their sibling and engage in simi- lar types of interactions as normally developing sibling pairs (Abramovitch et al., 1987; Knott et al., 1995; Stoneman, Brody, Davis, & Crapps, 1987). Observa- tional studies, however, have reported some differences in interactions. Specifically, children with disabilities, regardless of their birth order were more likely to show interactions with their sibling that were more typical of younger children, such as imitative behaviors (Abramovitch et al., 1987). Children with disabilities were also less likely to initiate interactions with their sibling than nondisabled children (Abramovitch et al., 1987). Further, siblings of children with disabilities tended to be more prosocial and nurturing towards their affected sibling than siblings of normally developing children (Abramovich et al., 1987; Lobato, 1991). Because impairment in social abilities is one of the deficits associated with autism, it seems likely that in- teractions of children with autism and their siblings may differ from other children with developmental disabili- ties. One study that specifically investigated the inter- INTRODUCTION Research in child development has tended to em- phasize parent–child relationships and relationships with peers (Stocker, 1994; Stocker & Dunn, 1990). Sib- lings, however, share a unique and important relation- ship with one another within the family unit (Knott, Lewis, & Williams, 1995). These relationships have been found to be important in the development of so- cial skills in early childhood (Dunn, 1988; Dunn & Munn, 1986). Positive relationships among siblings can also be an important source of social support for chil- dren and are associated with lower levels of conduct disorder and loneliness in children and higher self- worth (Jenkins & Smith, 1990; Stocker, 1994). Few studies have investigated how developmental disability in children influences interactions with sib- lings (Abramovitch, Stanhope, Pepler, & Corter, 1987; Siblings Relationships of Children with Autism Laura Kaminsky 1 and Deborah Dewey 2,3 This study investigated sibling relationships of children with autism compared to children with Down syndrome and siblings of normally developing children. Ninety siblings (30 per group) between the ages of 8 and 18 participated in this study. Results indicated that sibling rela- tionships in families of children with autism were characterized by less intimacy, prosocial behavior, and nurturance than those of the two comparison groups. Both siblings of children with autism and siblings of children with Down syndrome reported greater admiration of their sibling and less quarreling and competition in their relationships relative to normally devel- oping comparison children. KEY WORDS: Autism; sibling relationships; Down syndrome. Journal of Autism and Developmental Disorders, Vol. 31, No. 4, 2001 399 0162-3257/01/0800-0399$19.50/0 © 2001 Plenum Publishing Corporation 1 Department of Psychology, University of Calgary, Calgary, Alberta, Canada. 2 Departments of Psychology and Paediatrics, University of Calgary and Behavioural Research Unit, Alberta Children’s Hospital, Al- berta, Canada. 3 Address all correspondence to Deborah Dewey, Behavioural Re- search Unit, Alberta Children’s Hospital, 1820 Richmond Road S.W., Calgary, Alberta, Canada, T2T 5C7; e-mail: dmdewey@ucal- gary.ca