What makes people act in good or evil ways?

These are the first two paragraphs (so far) of my paper for a "Social Psychology of Good and Evil" course. I may upload the whole thing when it's done (as it is due tomorrow), but for now I figured I'd see what people think of the intro.

"All that is necessary for the triumph of evil is that good men do nothing." Edmund Burke

It is easy to see the world as all-good or all-evil. From cognitive psychology, studies in schematic thinking and heuristics tell us that making easy, definable categories which are performable in automatic ways will simplify a person’s life. While defining each can be a mess of logic, consensus, and parsimony, we all have within us some very real sense of certain acts being good or evil. In studies of morality, questions abound as to the nature of what “good” people are and what makes them different from “bad” people, if differences exist. In what often seems the bleakness of the world, its obsidian shroud of relativism and selfish desire, there can be some who uphold a strict moral code and believe in the pervasiveness of good over destructive behaviour and intent. To reach such a state of virtuous action, these “moral exemplars” have developed to act morally out of an “uniting of self and morality” (Colby & Damon, 1992, p. 310). Not only can these people be admired for their moral state, but their example allows an in-depth look into what bridges the divides between evil, neutral, and good.

In this paper, it will be argued that good and evil actions have their roots in how integrated one’s sense of self is with one’s sense of humanity, morality, and purpose. By “good”, I mean to say constructively adding to humanity through beneficial acts to individuals or groups, whereas “evil” will be defined as avoidable harm committed against others or the unwillingness to help avoid or alleviate harm if such is possible and will not result in further harm done. Alternatively, another appropriate definition is provided by “Irving Sarnoff: ‘Evil is knowing better but doing worse’” (Zimbardo, 2004, p. 22). Since they are not mutually exclusive, both definitions for evil will be utilized. Since “humanity” can be defined in different ways, here it refers to all human “in-groups” being conceptualized as unified, and a respect for humanity denoting some degree of reverence for “the value of human beings and of human life, their worth” (Colby & Damon, p. 317).

Hopefully no plagiarism will be taken from the above, but I'm sure if you want the reference the date and author will give you enough, and if not I can definitely mention it later.