17 year olds may be able to do all of those things, however we know that the average male's forebrain doesn't fully develop until much later, as much as 8 years later. Some males aged 25 still have not developed to the point of advanced reasoning. Reasoning like being able to see the consequences and harm done by stunts such as sending threats like this. It's certainly not enough to dismiss this and say "he's 17, he's not a child anymore".
Who cares about a "fully developed" brain, if there is even such a thing? Human beings at any age are largely irresponsible and irrational and most people never move beyond this. Yet I know that the vast majority of 17-year-olds I have encountered do not mail boxes of ashes to Jews, or anything of the sort. That his brain is not totally "developed" absolves nothing. Should a person with an IQ of 100 serve less time than a person with an IQ of 140, because the latter is more "capable of rationality", or whatever other quality you want to ascribe to the mind? At some point, certainly short after the reasonable age of entry into the working world (probably sixteen) people need to be expected to act decently. Sure, I'm in favor of rehabilitation -- punishment is a revenge-instinct and waste of resources -- but we should do ourselves and these people the service of being honest about what they are: criminals.
That sounds so weird. This is particularly males? Males with healthy diets and lifestyles, ones with terrible diets and bad lifestyles, or across the board?
Especially since the average male lifespan was around 35 years up until a few millenia ago. Are you saying that most males died before they reached maturity?
AFAIK 'average male lifespan was around 35 years' is based on estimates that includes all males including the relatively large percentage who never survived childhood
