I think everything you said is right, but then what makes human hate their out groups? I mean, apart from "this is in human nature, to consider wrong and legitimately hateful everything that is not part of their in group"?
Also, it is entirely true that if every human being actually examined their deep thoughts and beliefs, there will probably be less hatred in this world. However, I was wondering: do you think it could ever be a reality to live in a world where people truly understand others and then there would be no hate and no discordance at all? Or as species, we will always be selfish for our descendants sake?

Thank you for this article, it is a very true and inspiring thought that you underlined in here. I hope a lot more people could be sensible to what's written above, so that selfishness could fade away, at least a little more.