It's an interesting correlation. It should be remembered that people with poor impulse control are more likely to find themselves in situations where several cranial injury is likely to occur. It may even be a vicious cycle.

I think it's worse than that. I think some of them take illicit drugs because they hate being that way and are trying to control it in the absence of a proper diagnosis and proper intervention. And then they get vilified as "addicts" for self medicating to keep themselves chilled out.

Edit: And of course there will always be the assholes with an excuse for their intentionally malicious behavior, which complicates the hell out of finding good solutions.

I think this talk is relevant. It's not specifically about convicts but includes them.

"The most important lesson from 83,000 brain scans | Daniel Amen | TEDxOrangeCoast" https://www.youtube.com/watch?v=esPRsT-lmw8

My summary of the thesis of the talk: Brain injury is far more common than is generally realised, contributes to many kinds of behavioural issues far more than is realised, is visible on scans, and is to some extent treatable, but it's usually not considered or examined.

Do you have a recent source on the head injury / death row connection? I am not doubting you but curious. I can find a study of 15 people from the early 2000’s but is there anything more recent and with a larger sample size?

I'm old. That old study you found might be the one I'm thinking of.

I don't have any other sources at my fingertips that wouldn't involve just doing a search myself.

you aren't going to get a very large sample size of death row inmates...

Can also be due to hormonal issues, which in turn may be exacerbated by gut micro biome issues.

I'm sure there are many factors. At one point while very sick and homeless, I was coming across like a bipolar person to some degree. I did some research and adjusted my diet to shut that down.

I imagine that poverty and poor diet do all kinds of bad things to the populations that tend to be most at risk of ending up in jail in the US. I have at times fantasized about trying to do something about nutrition in the US prison system as a means of trying to break the cycle, but I'm probably never going to be in a position to do that.

Even the Bible posits that feeding people is the way to promote the peace, basically. Psychological research and firsthand experience suggest that's pretty sound as an approach.

Edit: See discussion here:

https://news.ycombinator.com/item?id=16140867