Who says humans are evil BY DEFAULT?

I think humans are shit. I think a very few are strongly evil. I mean someone came up with the idea and others actually boiled people alive. That ain’t good. The ones doing the boiling would probably not have done so without the ones who thought it up, but does that make them good by default? Also I think given the opportunity to take a million of someone else’s dollars there is a much larger portion of the population that would do it than thinking up tortures. So what’s the definition? How far do you have to go to be evil? How much do you have to resist to be good?