Actually, until the age of 25 (average), your logical thinking skills are limited in risk-assessment and cost-value assessment. This is a clinical fact, and one that has been recognized by insurance agencies for many years.
The common experience and frequency of continental wars used to kill off the foolish and psychopathic in sufficient quantity that their overall affect on the "mature" populace was retarded. Since we are "kinder and gentler" now, and do not have wars on the scale we once did, we now have gangs. See how we deal with them and their impact on society and draw your own conclusions. (I can get the title/author tonight, if anyone is interested)
Bottom line, to me, is that we treat our children too much like children, for waaay too long, in the First World. Maturity comes with some pain and suffering from bad decisions, and having to deal with the consequences oneself. Given our modern structure, it is a rare 18y/o that I would trust with a firearm in an open social setting (vs being in combat, hunting, at the range, etc.,), where a forceful, mature authority figure was not closely, intimately, present to restrain the testosterone.
Regarding felons, in the traditional sense of the word(rape, murder, armed robbery, hostage taking), and not many of the BS "ratings" of felony one can be convicted under today, the demonstration of asocial behavior demonstrates that the individual does not wish to participate in society, but feed off it. That is, to me, a personal declaration effectively saying that one does not wish to have the rights of a citizen.