INITIATORY AND REACTIVE BEHAVIOR IN YOUNG-CHILDREN WITH A PERVASIVE DEVELOPMENTAL DISORDER - 2 INDEPENDENT COMPONENTS IN COMMUNICATIVE-BEHAVIOR FOR DISTINGUISHING SUBGROUPS

Thirty-three children with a pervasive developmental disorder (PDD) were classified to be either ''aloof', ''passive'', or ''active but odd'' according to Wing's classification criteria (Wing & Attwood, 1987). These subgroups were compared with each other and to a control group of 33 normally developing children on the basis of behavioural measures derived from direct observation. The children were observed during an individual play session with a child psychiatrist. The comparative measures were frequency counts and transmission indices derived from sequential analysis (Steinberg, 1977; Van Hooff, 1982; De Vries, 1994). Two independent components in the communicative behaviour of the children were found to distinguish the PDD subgroups from each other in different ways: Initiatory behaviour on the one hand appeared to discriminate between all the 3 subgroups with respect to its level of occurrence as well as the effect it had on communicative acts of the child psychiatrist. Reactive behaviour on the other hand only discriminated the aloof group from the other two groups. Discrimination was seen in the frequency of this behaviour and its predictability in response to the child psychiatrist's communicative acts.