Electroencephalograms of XYY and XXY men.

Abnormal EEGs have been reported in XYY and XXY men located in psychiatric hospitals and prisons. In general, persons resident in institutions are more likely to exhibit EEG abnormalities than "normal" population, and this bias of ascertainment has complicated the interpretation of these results. The present study was conducted in Denmark. Chromosome determinations were made on 4,140 men selected from a birth cohort of 31,438 men. Twelve XYY and 16 XXY men were detected. Appropriate XY control groups were selected from the same population. The XYY men were found to have a significantly lower average frequency of the occipital alpha activity than their controls. The XYY and XXy men showed significantly more theta activity than the controls.