Electroencephalographic studies were done on 25 dyslexic and 25 normal reading children (all between the ages of 8 and 13 years). Results indicated that, of dyslexic Ss showing evidence of unresolved dominance in the EEG recordings, 35 percent of cases were possibly genetically determined with a further 40 percent possibly neurologically impaired. Inter-group findings revealed differences in the amount of alpha activity in the two hemispheres with dyslexic Ss showing more activity on the dominant side or no difference at all, whereas controls showed more activity on the non-dominant side. Findings suggested the presence of lateral dominance and cortical organization in the control group on normal readers and no comparable resolution of dominance in both the genetically and neurologically determined cases of dyslexia. (DB)