Fetal Alcohol Syndrome
My money is on inbreeding. How many know who their daddy is? So they don’t know who they’re making babies with either. Daddy can impregnate daughters, brothers sisters, hell, even Maury couldn’t figure out who is related to who. And they keep churning out the blank-eyed, drooling future criminals.
FAS means that they are impulsive with no ability to control themselves. And that their IQ may be basement level. Frankly the death penalty would fix what is unfixable here.