The environment and upbringing that people were raised with plays an important. role, perhaps. Emotional wounds and mishaps, values that their parents passed on expressed by their actions and words, social status, gender, etc all play a significant role in shaping a person's mind and his or her thoughts. One thing in common though, I feel, is that they all feel as if what they're writing is right AND they don't believe thay anything else can possibly be. The greatest difficulty lies in being able to say, sorry, I was wrong and admit your mistakes and change your views when presented with sufficient, quality evidence. I feel like there always will be people filled with and sowing the seeds of hate, because this is reality and the world cannot be 'fair' to everyone.