"Wha? Well, all I can say is that such a claim certainly requires justification before being taken into consideration (along with all the other hyperbole one finds these days)."

Groth (1979) found 33% of adult male sex offenders were themselves abused by female perps. Petrovich and Templer (1984) found 59% of male sex offenders had themselves been abused by female perps. Johnson (1988) found that 49% of boys, aged 8-13, who had sexual abused other children had been abused themselves by female caregivers.

I have to ask, though ... did you seriously think sex offenders simply appeared out of thin air? HUGE majorities of criminals have mental health issues, addictions, histories of abuse or neglect, FAS/FAD, etc.  Why would sexual offenders be any different?