[Myrddin]

The prison population contains a disproportiate number of "supermales" with XYY genomes. They are less intelligent, more aggressive and have statistically higher criminal tendencies than normal "XY" males.

[Poohbah]

Isn't the "XYY" genome somewhat questionable? I seem to recall reading that the evidence is thin (and some would say anorexic), with a lot of controversy surrounding the interpretation of the evidence.