I think this is an interesting article but the author's conclusion is flawed. The sample he's studying is biased because the prison may be filled with low IQ individuals but maybe it's filled with low IQ individuals who are bent towards criminal behavior. He'd have to sample non-imprisoned low IQ people. The lack of empathy is not a result of low IQ.

I've met dumb people who could still display basic empathy. I would guess that the low IQ of criminals is a result of upbringing i.e. a lack of empathy experienced during their childhood years. There are intelligent criminals. The world is run by intelligent sociopaths, so are most corporations.

Most of these criminals were most likely raised by single mothers. They were probably abused by those single mothers or their string of sketchy boyfriends or family members.

Their low IQ is probably a mixed factor of genetic potential, with serious developmental issues from childhood abuse, long term substance abuse and childhood neglect.

I've met plenty of law abiding people who fit some of these descriptions. Maybe low IQ people are predisposed to crime and a lack of empathy but I think this article's conclusion is missing other relevant and significant factors.