I am a firm believer that the heart of a person is made up of three parts: character, conscience and emotions. You build a child's character using what I spoke about above and that influences her/his conscience, which then steers the emotions and or devotion towards that which is good. If you turn that list of three upside down, then you get a person who's emotions control their conscience which in turn poisons or warps their character. If you think that through you can imagine what a person is capable of if that happens.