A COMPARATIVE STUDY OF THE CONVERSATIONAL SKILLS OF FRAGILE-X, AUTISTIC, AND DOWN SYNDROME INDIVIDUALS

This study compared the conversational skills of three retarded populations: Fragile-X, autistic, and Down syndrome. The main purpose of the study was to establish differences in conversational skills in these populations. A further purpose was to establish the effect of level of I.Q., age, and expressive skills on conversational performance, in these retarded populations.

Fragile-X has recently been established as a distinct genetic entity. Some individuals with Fragile-X also have autism. There is, therefore, an overlap between these two populations. One question posed by this research was, "Can the two populations, Fragile-X (non-autistic) and autistic (non-Fragile-X), be distinguished by their conversational characteristics?"

The subjects were 18 Fragile-X males, matched for sex, I.Q. and age to 18 autistic individuals and 18 Down syndrome individuals.

Thirty-minute audio recordings were coded for a wide range of conversational variables, designed to evaluate the degree of conversational participation, appropriateness, expressive skills, and fluency of the subject groups.

Results confirmed that the Fragile-X population is significantly different from the other two groups. In particular, the Fragile-X group used most eliciting utterances and most partial repetitions of self; the autistic group used most multiply inappropriate utterances; the Down syndrome group was most dysfluent. Retarded groups therefore appear distinguishable by their conversational skills.

Lower I.Q. individuals, across all the groups, used more inappropriate routines and repetitions. Higher I.Q. individuals provided more unsolicited information. Those subjects with a low M.L.U. had greater difficulty with identifying referents, and providing appropriate responses to questions. Finally, with age, subjects became more conversationally passive, using more minimal responses.