I think people are naturally more good than bad(in overwhelming proportion). The reason why we are like that is because we are wired to be social. An association makes sense, like Steve Jobs used to say, when is like Beatles: when the group worth more than the sum of all individuals. This is why the most majority of people have something deeply wired in their brains: empathy. Empathy makes us living and feeling a bit of other people experiences, and we don't want to have bad experiences.
Being social is also making us behaving bad, and some regimes like Nazis or communists were trying to exploit that bad nature. We need to be a part of the group. When the group is in danger we feel that we need to become a part of the group and delegate our power to the group which is usually represented by a leader or a group of leaders. They use that power against what is perceived as a threat for the group(enemies from outside and inside). Those enemies are dehumanized through hate, and they are regarded as simple subjects without emotions and feelings, the empathy is blocked, so any possible crime is possible without remorse against those hatred de-humanized humans.
The problem with delegation is that the individual no longer feel responsible for the acts he empowers because he doesn't do those personally(and in dictatorship once he delegated the power it's too late to get it back).
So my conclusion is that we are wired to be good but we should take care, because we have some really nasty bad monster deeply hidden in us, which takes control if we feed him too much hate.
it's all depends on how a person was raise and who raise him and who surrounds him,
so the TOTAL answer is there is no such thing as GOOD or BAD in NATURE!! :))