Human's aren't evil per se, just selfish. Evil things that come naturally just come from our survival instinct. Human's are, if their baser desires are fulfilled, naturally somewhat good. Unfortunately, since social pressure is so strong and tends to take priority over thought, people end up rather intolerant and close-minded, hence a lot of war and genocide in history. Though there are some tribal instincts in there, a lot of it is social.
As for the Tabula Rasa thing, people are a blank slate other than the instincts I mentioned above and some genetic things. And genetic things, with behavior, aren't strong unless enabled by an environmental factor.
As for the Tabula Rasa thing, people are a blank slate other than the instincts I mentioned above and some genetic things. And genetic things, with behavior, aren't strong unless enabled by an environmental factor.