XYY Chromosomal Constitution in Prison Populations

IN 1965 Jacobs et al.1 found seven of 196 males at Carstairs, the Scottish State Hospital, had a chromosome complement of 47, XYY and studies of the inmates of similar institutions in England2, Australia3, Denmark4 and the USA5 have confirmed this. The height of many males with a double Y chromosome was 180 cm or more. This raises the question, is there a similar high incidence of 47, XYY males among the inmates of prisons? Reports relating to prisons and other penal institutions2,6–8 have shown considerable variation in the incidence of 47, XYY males (Table 1).