Are humans inherently bad, evil? Or are they born in a state of essential perfection and purity, and do they become corrupted with time? Is human nature basically good, or basically not? Where does evil and the tendency to act “good” come from? Well, it really depends on who you ask.

People can give all kinds of examples and explanations for either side of the debate (and it’s not just limited to those two polar opposites, either).

It’s a question/problem that has plagued humans for quite a long time, probably ever since we have lived together and formed societies of any kind. Philosophers, adherents to all manner of religion, and scientists alike have all pondered and debated this question.

Whether you think people are inherently bad or inherently good or that environment and other people have a big influence on the matter, you must admit that there exists in human society those who act in seemingly bad ways and others who act in seemingly good ways.

As far as my definitions of “good” and “bad” go, I do not in this particular instance necessarily equate them with “moral” and “immoral”, at least not in any religious sense. I do think that there is big a social component involved and that “good” actions are often ones that are socially positive (i.e., acting in a selfless manner towards another person) and “bad” ones are socially negative (intentionally causing harm to someone else).

What does this mean for humanity? Are some people just inherently worse than others? Why do some turn to “bad” acts while others “good” ones? Is it nature, nurture, sociology, culture, something else entirely?

Evidently, there is some association between “bad” or antisocial acts (or “good” ones) and the amygdala. According to Michael Stone, a clinical psychiatrist, “murderers and other violent criminals have been shown to have amygdalae that are smaller or that don’t function properly.” This sentiment, specifically about proper functioning, is echoed by neuroscientist Kent Kiehl, who thinks (based on research) that psychopathic people have impairments in their brain. Conversely, people who have historically performed in an altruistic manner, that is, in an extremely selfless manner, have in some cases been shown to have somewhat larger amygdalas. The amygdala plays a big role in one's capacity to feel empathy for others, so it makes sense that a smaller one would mean that one might act in a less positive way towards others.

This doesn't mean that people are guaranteed to act in a better or worse way, though. The environment that a person grows up in also shapes that person.

As part of this environment, groups can also shape any ordinary person to behave in a manner that most people would view as "evil." Philip Zimbardo has done much research on what he terms "The Lucifer Effect," where "transformations of human character...in which ordinary, even good people begin to engage in bad deeds, for a short time or longer, that qualify as 'evil.'"

He wrote a whole book on this, but one main factor he found that contributed to the perpetration of evil, and particularly evil done by groups, was that in order to commit evil against others, the others were first dehumanized. There are tips on how to resist this effect here, tips that may be useful in the current polarized political atmosphere.