Brain = Computer
Frontal Lobe region of the brain = The computer’s firewall system
With a functional frontal lobe region, you’re able to differentiate right from wrong (granted, first learning what is right and what is wrong are determined via social conditioning), and also better able to determine a good situation, place, person, etc. from a bad one. Just like on a computer, if you have a functional firewall system, you’re able to determine which websites or downloads are safe and which aren’t.
Now if you damage your firewall system, then your computer is still able to function relatively normal, only except you won’t be able to determine good/safe sites from bad/unsafe ones, and subsequently downloads as well, leaving you quite vulnerable to making bad decisions with detrimental consequences. The same applies with damaging your frontal lobe region, in which the brain would no longer help you learn how to differentiate right from wrong, and good decisions from bad ones. As a result, you’re then far more susceptible in getting in trouble or harming other people and/or yourself.
Studies have shown that plenty of serial killers show damage to the frontal lobe region of the brain. Some may see this as being the cause of their murderous tendencies, whereas others completely negate the fact of damage and instead argue that social conditioning was the reason for said tendencies. I, myself, see no reason why both can’t be right – to some extent, that is. Both nature and nurture play big roles in the developing an individual, which makes up their thoughts, feelings, and actions.
A person with a healthy brain can still make very bad decisions, just as a person with a not-so-healthy brain are still capable of making very good decisions. How both their conditioning and biological computations operate helps determine the individual. Saying it’s only one or the other is, quite frankly, nonsensical.