I have just finished an online course called the "The Science of Happiness" and it showed me some aspects of human nature are genetic; as in happiness is 50% genetic 10% environment and 40% self-defined. Forty percent gives us a lot to work with and if some effort is used we can use much of that percentage to permanently increase our personal happiness. I believe it would be similar for being good or bad. However most people need a little outside influence to guide them in shaping that 40%. I guess if your 50% genetic level is predisposed to be mainly a bad person than it would be difficult to get that person to be very kind. But we should still help them since we could guide them to become at least a neutral person who would not be damaging to society.
I started a new course today called "The Science of Stress" and I'm sure it will give me some key insights to both my own personality/life and that of others. I never try to force anything on anyone but I do try to pay it forward with the lessons I learn.
Have a good day everyone.