Unlike other IQ tests, the Leiter-R emphasizes fluid intelligence, the truest measure of a person's innate intelligence. This makes Leiter-R a much more accurate, and fair, measure since the IQ score is not significantly influenced by the level and quality of the child's educational, social and family experience. For example, with the Leiter-R, hearing-impaired and ESL youth were only .33 Standard Deviations below the mean, as compared to typical findings of a full Standard Deviation difference, for such groups when using verbally-loaded tests. Also, since the Leiter-R scores do not change significantly in the adult years, so it can be used effectively with older subjects.