[Jimbee (OP)]

There are a lot areas where science and law interact, and some where they come into conflict. One is the insanity defense. Every nation has had some version of the insanity defense since recorded history. Even the ancient Romans did. Even ancient Islam did. (One message board said the Koran never talks about an insanity defense. I don't know where in the Koran it says that. But I know it has something about an insanity defense. Or maybe diminished capacity.)

Insanity means you couldn't possibly know the difference between right or wrong, or you didn't even know what you were doing or that it was wrong. And the more recent Durham rule says the accused is not responsible if the unlawful act was the product of mental disease or defect. And there is something (that I haven't heard in a long time in my country in any news report) called diminished capacity.

Anyways, on the subject of dimished capacity, I was wondering about behavior issues mentally ill and handicapped people can have that are caused by damage to their prefrontal lobe. Something like a traffic accident could cause it. I've heard it sometimes occurs in intellectual disabilities. And my understanding is that some people just have perhaps smaller brains, or poorly developed prefrontal lobes. The same way the visual or auditory centers of their brain might be poorly developed, though not damaged.

I guess this shouldn't count as insanity. But what about dimished capacity? And I'm curious, how is this handled in other countries? Like Europe, Canada or South America?

[alancalverd]

Insanity or diminished capacity should alter the charge but not the verdict. Murder, for instance, requires proof of intent, whereas manslaughter or unlawful killing simply requires proof of action.

"Genetic predisposition" was occasionally offered as a defence in the USA until a Texas court ruled that uncontrollable genetic predisposition to killing warranted an automatic death sentence.