Examined with 38 right-handed boys who were either dyslexic or normal readers and matched for age and IQ (mean age both groups=10.6, mean IQ normal readers=106, mean IQ dyslexic readers=105) were the weak, strong, and equal lateralization theories of dyslexia. Cerebral lateralization was measured for linguistic material (digits) using the dichotic listening technique. No difference was found in mean lateralization score between normal and dyslexic groups; however, the distribution of the lateralization scores of the normal Ss appeared unimodal whereas that of the dyslexic Ss appeared bimodal. The results suggested support for both the weak and the strong lateralization theories of dyslexia. (Author/IM)