It's all about the way people are brought up.

I would dispute this because I was raised by the most racists bigoted wankers you could ever wish to meet. My family are scum. I'm the exact opposite of them. I have a diverse groups of friends, race, religion, sexual orientation you name it.

It's not how people are raised but because they hate themselves so hate others. That's what I observed with my family anyway. I never understood why they would hate people that were different from them and so I had to hide me friends from them. My mother "if you come here with any of those kind we shall kick you out". Well they did anyway.

People conform to fit in because people survive in tribes. We now live in a world where you can thrive alone and hopefully, those attitudes will die out.