A recent Time Magazine article, What Makes Us Moral, investigates the issue of human behavior. From the introduction:
If the entire human species were a single individual, that person would long ago have been declared mad. The insanity would not lie in the anger and darkness of the human mind—though it can be a black and raging place indeed. And it certainly wouldn’t lie in the transcendent goodness of that mind—one so sublime, we fold it into a larger “soul.” The madness would lie instead in the fact that both of those qualities, the savage and the splendid, can exist in one creature, one person, often in one instant.
Morality may be a hard concept to grasp, but we acquire it fast. A preschooler will learn that it’s not all right to eat in the classroom, because the teacher says it’s not. If the rule is lifted and eating is approved, the child will happily comply. But if the same teacher says it’s also O.K. to push another student off a chair, the child hesitates. “He’ll respond, ‘No, the teacher shouldn’t say that,'” says psychologist Michael Schulman, co-author of Bringing Up a Moral Child. In both cases, somebody taught the child a rule, but the rule against pushing has a stickiness about it, one that resists coming unstuck even if someone in authority countenances it. That’s the difference between a matter of morality and one of mere social convention, and Schulman and others believe kids feel it innately.
… and from the conclusion:
For grossly imperfect creatures like us, morality may be the steepest of all developmental mountains. Our opposable thumbs and big brains gave us the tools to dominate the planet, but wisdom comes more slowly than physical hardware. We surely have a lot of killing and savagery ahead of us before we fully civilize ourselves. The hope—a realistic one, perhaps—is that the struggles still to come are fewer than those left behind.
While the general question is certainly an interesting one, I find it particularly relevant with relation to religion. People seem to have this idea that (at least for religious people), morality is defined in their ancient texts. It follows, then, that the rest of us (atheists, for example), have no reason to follow generally-accepted moral teachings. Personally, I feel this is complete garbage. There’s little evidence that religion has anything to do with morality, and many of the teachings of books such as the Christian Bible are filled with immoral acts performed by none other than God himself.
Evidence and studies show quite the opposite: Human beings (and other animals) exhibit traits and behaviors that are inline with what we consider “morality.” Much of this is independent of learning, and has roots elsewhere. Richard Dawkins, in The God Delusion, describes studies that show that there’s no correlation between religiosity and the decisions people will make when presented with difficult decisions. The Brights organization has also started a project to investigate the same. For details, see “Action Arena #1: Reality about Human Morality.”
Overall, I hope that these studies will have some impact on making the human race less violent (especially in the name of religion). History shows that it’s unlikely to help, but there’s always hope.