Asperger syndrome and clumsiness.

I read with interest the brief report by Ghaziuddin, Tsai, and Ghaziuddin (1992) in this journal referring to clumsiness in Asperger syndrome. The authors of that report cited a study from our center (Gillberg, 1989) and built some of their arguments around that citation. The authors cannot have read the paper they quote. They say that in the Gillberg (1989) study "a cutoff score of 15 and above on the performance subscale of Griffith's scale was used to classify patients as clumsy; however, the rationale for using this as the cutoff point was not explained." This is the wording of the original paper: "Clumsiness was diagnosed as a score of the gross motor subscale > 15 points below the child's IQ level." Thus, it was the gross motor, not the performance scale (which is a completely different subscale on the Griffiths scale). And it was definitely not some arbitrary score of 15 and above, instead it was a score of 15 or more below the child's IQ level. The rationale for using the cutoff point should be implicitly obvious given that this standardized test with documented psychometric properties (the Griffiths gross motor subscale) yields a developmental quotient with a population age cohort mean of 100 and a standard deviation of i5. Clumsiness was thus expressed in terms of an IQ-related deficit in gross motor skills, which, although far from perfect, should be a reliable and reasonably valid means of diagnosing clumsiness in a manner that can be reproduced by other researchers. I agree with Ghaziuddin et al. (1992) that "if clumsiness is indeed an important feature of Asperger syndrome, it is crucial that it is not only properly defined but also properly assessed." Clumsiness was properly defined and assessed in our study. If a "reapraisal of clumsiness" is to be of value to the readership it is crucial that those who take on the task of reappraising actually read the papers that form the basis for their analysis.