Situation: You're offered insider information from a friend who swears you to secrecy.
Nice guy: Thanks his friend but says he doesn't want to use it because he doesn't want to take the risk. He also feels it's morally wrong, but is too embarrassed to give that as a reason, knowing he would be mocked. When his friend tells him he should do it for the sake of his family, he feels bad about that, but still demurs. Worries about his friend. Worries that he himself might be legally liable just for having heard the information.
Average guy: Asks his friend over and over if the chain of information is airtight. Uses the information. Doesn't really feel that guilty about what he views as a victimless crime, but worries a lot about being caught. Tells himself this is the last time he'll do it, but when his friend offers him another piece of insider info, he thinks of how much he could make and succumbs again. When finally caught, he tries to stonewall, and doesn't give up his friend. When convicted, he feels almost as badly for his family as he does for himself.
Sociopath: Buys more stock than his friend recommended, and also passes the info along to a couple of acquaintances he wants leverage over. Boasts to others that he is privy to "special" information about the stock market, to show how well connected he is. Spends the money on a flashy car, flashy clothes, and fancy summer house rental. Assumes he won't get caught; when he does, he immediately offers to give up his source as well as the two he passed the info along to in exchange for leniency.
Situation: You become a priest.
Nice guy: Volunteers to work in a parish in a poor neighborhood, ministering to the needy, trying to help them improve their lot. Helps out in neighborhood doing non-priestly jobs like helping tutor students. Is tormented by his homosexuality, and doesn't act on it. Actually says his prayers when he goes to sleep at night.
Average guy: Is drawn to the profession because he wants to cover up his homosexuality, make a steady income, and have reputation as man of god. Enjoys the trappings and ceremony of the church. Is proud of his knowledge of Latin. Enjoys the respect of his parishioners. Has an affair with a younger priest.
Sociopath. Treats his parish as a business. Founds a "Help the Children" charity for orphans abroad; sees this as a perfect opportunity to molest boys who don't have parents who will come after him, in countries without strict enforcement against molestation. Many young boys are permanently scarred by his attentions. Pockets half the money he raises.
Situation: What do you usually tell people about your family?
Nice guy: Talks about how grateful he is to his parents, and how sweet his sister is. Tends to assume everyone else has the same close, loving relationship with their families he does. His friends think he's boring because he goes home to see them so frequently.
Average guy: Talks about his family rarely since he mostly talks about himself, but when he does he complains about what turkeys his parents are, and how his sister is a pest. But deep down, despite being embarrassed by them, he loves them.
Sociopath: Almost never talks about his alcoholic mother or absent father. (He is estranged from his mother and hasn't seen his father in years.) After a few years, he decides to make up a story about how his father was a Rockefeller, but was disinherited, and changed his last name; he likes the way people treat him when they find out he is really a Rockefeller.