My own personal opinion is that we are all born neutral. Oblivious of the good and bad things going on in the world, setting foot into the unknown. So innocent and helpless, however as soon as we enter society, everything could change for better or worse. Their surroundings, parents, family, friends all influence the type of person that will emerge.
I think that parents are the main teachers in a childs life, what they teach their children, will be passed onto the next generation. We are conditioned by mainly family and people that surround us on a daily basis. After all how could someone say they were born good or bad ? We are not machines or computers that have been programmed to be an ideal race. People as human beings are sensitive to their surroundings and how they act in certain situations. Everyone is different because of their background or experiences they have had growing up. We take in everything we see/hear, it is not as if we can block the bad things out and continue on as if nothing happened. Our society as a whole is what makes us who we are.