To go off what Flamezdudes said, humans are neither inherently good or bad. I think they vary given their circumstances.
I think that, rather than good and evil, there are two forces at work that result from human interactions - a move towards harmony, or a move towards chaos. Nature is chaotic, but not evil. In fact, nature breeds novelty out of chaos. Isolated islands force animals to interact more, rather than expand into niche territories, and this leads to initial violence. Darwin found that it also leads to much faster evolutionary adaptations. Similarly, harmonious societies don't "evolve" technologically as quickly. Native Americans had territorial conflicts, but didn't generally seek to eliminate their opposition entirely, or to integrate other tribes into themselves (the method of the Western world for excusing violence and empire building). You see a similar story in massive asian agricultural communities, which survived relatively unchanged for hundreds of years before being destroyed or absorbed by technological expansionist systems.
You can even take humans out of the equation. Every atom represents conflict - a massive, positively charged center, orbited by a tiny negatively charged particle. This is the basis for all chemical interactions, which is the basis for matter as we know it. Nothing would exist without some element of chaos.
So what's "good" then? Harmony? How does one go about creating harmony? On an individual level, harmony works - you can strive to live harmoniously with yourself and the people around you. If everyone did this, we'd probably have a bitchin', good-natured society. But we're too busy chasing money, our new evolutionary imperative, to devote much time to this. So we outsource the struggle for harmony to leaders. I personally think the most ideal society would be one under the rule of a benevolent dictator, but this is, of course, a fiction.
The problem is that you may have good leaders at first, but over time, the system gets corrupted. Money and favors influence it. We have a new problem in that the media is so widespread that we don't even try to hold our leaders accountable - we simply follow those that make us feel good. As evolved as we think we are, the average person is not that different from a an ape with very advanced language skills. Most people don't develop new ideas or fundamentally question their values (in fact, in western society this questioning is often defined as neuroses or insanity). Instead, we find the monkey who looks like he knows what he's doing, and follow him (and it's almost always a him, but that's a different topic for another day

).
I'd recommend watching this video - it's a long one, but it goes into several psychological experiments that highlight logical fallacies that are simply a byproduct of the way the human brain works. We almost invariable suppress our individual reason in favor of supporting authority. If you don't have time to watch it, at least watch the man speaking at the end of the video, and look at how ape-like his behavior is. He conveys a sense of power, and stirs emotions in his audience. He fucking mind-controls them.
So to me, a more interesting way to look at it is "Are humans inherently lawful?". Different societies define good and bad differently, often dressing it up as written mandate. An intelligent person will always question whether the law actually serves mankind, or has some ulterior motive (or is simply outdated). And if a law sounds good, we will often follow it to the letter. Is stealing really wrong if the business you're stealing from is insured? And the insurance company itself steals from and exploits millions? And is backed by the Federal Reserve, which can continue to print money that isn't backed by any real value? Who is the victim here? Take a look at the "Drug War" to see how easily people are led into thinking something is "wrong" because authority figures tell them it is.
In my opinion, 99.99% of the most heinous acts in history are committed by people who either think they are doing the right thing, or have been brainwashed by authority figures. Good and evil don't even apply. You think every Nazi was evil to the core? Of course not. Most of the individuals thought they were in service of some greater good. The Spanish Inquisition murdered and tortured people because they believed 100% that they were saving those people from eternal damnation.
Phew, didn't think that one would run that long. Anyway, TLDR: Good and evil are simply concepts defined by authority figures. On an individual level, humans value kindness and harmony over discord. But we're monkeys, and we've survived to this point by listening to monkeys that convinced us that they have the answers. Think for yourself, take nothing for granted, and you'll make the world a better place.