The study compared the Halstead-Reitan (H-R) neuropsychological test profiles of 25 normal, 47 learning disabled (LD) and 20 brain damaged (BD) young adults. Multivariate analyses indicated that the H-R battery could differentiate these groups beyond chance expectancy and that the neuropsychological deficits in LD performance are intermediate in severity between normals and BD. In an investigation of subtypes of LD based upon their neuropsychological test performance, multivariate analyses suggested that LD young adults can be subdivided into those with mild (low LD) and those with more noticeable (high LD) cerebral dysfunctioning. Measures of mental flexibility seemed most sensitive to normal-low LD group differences. Further, there were significant differences in the performance of normal, low LD, high LD and BD groups on the Rey Auditory-Vocal Learning Tests. Differences were due to qualitative differences in information processing. (Author/CL)