Between 1 in 4-6 boys are sexually abused in the United States; 90% of the time by someone known to the boy, often another male. Boys are more likely to be sexually abused by straight males than gay males. Most abusers were once abused themselves. (Gurian, Michael. The Wonder of Boys. p 233-243 NY: Jeremy P. Tarcher/Putnam, 1996.)
Refer to Trauma and the Brain for additional information.