Word identification in adults with mild mental retardation: does IQ influence reading achievement?

To assess the relationship between word identification and intelligence in adults with mild mental retardation (IQ < 80).

A standardized evaluation was administered to 67 adults with mild mental retardation. The evaluation included a psychiatric interview, the WAIS-R, and a 2-h interview with a speech therapist and reading tests.

Causes of mental retardation were diverse in the sample, and IQ scores ranged from 43 to 79 (mean score = 64). All subjects exhibited reading impairment, including 69% with severe impairment. No subject with an IQ score under 65 was able to perform adequately in the word identification tasks. Word identification was correlated with total and verbal IQ, but not with performance IQ.

Our results suggest that, in contrast to subjects with normal intelligence, IQ score is correlated with reading in subjects with mild mental retardation. Finally, remediation should be preferentially implemented for subjects with IQ score greater than 65.