Why Did the Lamanites Hate the Nephites So Much?

Today I read Mosiah 10 and I find it interesting that the Lamanites hold on to their cultural hatred for so long.  It really makes me wonder why.  Again I think it has to do with the culture.  I think back to my childhood during the Cold War and the enemies of all Americans were the Russians.  I remember playing games where the bad guys were the Russians.  Did I hate them though?  Absolutely not.  I just knew they were the enemy.  Is this how the Lamanites were?  Perhaps as children but then as they got older their parents instilled in them more hatred and fear.  When I was 9 the Berlin wall came down and so the Russians were no longer the enemy.  We had no enemy.  So for the bulk of my life I have not feared or seen any group of people as an enemy.  I'm honestly not sure what to make of the Lamanites true, unwavering hatred of the Nephites.  I think it must be a cultural thing and I suspect it did not afflict each and every one of them.  Just the majority.  Until tomorrow.