I assume it's taught and is often hard to unlearn.
throw in some bad experiences and people learn to be racists.
Nope, it's not so much that it's "taught" as it is the way people believe, and their kids generally take those beliefs as their own.
But................not always. I happen to be an example of being raised in a racist environment, but know that racism is stupid. I grew up in Montana, and my Grandparents thought that if you weren't white, you weren't right. They didn't differentiate on the various shades of brown or black, they didn't like anyone who wasn't white.
I also remember the day I shipped off for boot camp. My Grandparents told me that I was going to meet some of the best people I'd ever get to know, and to feel free to bring anyone home, just make sure they were white.
Well................I thought that was a pretty stupid statement to make, and as chance would have it, my roomie in "A" school was a black dude we called LA (it's where he was from), and he and I got along great. He taught me about black culture, and I taught him about rock and roll.
And, if I was a racist, that would mean that I wouldn't listen to anyone not like me, because I would be thinking that only my kind had anything useful to offer. And, if I had taken that attitude, I would have missed out on a whole bunch of new information, and I would have also missed out on some of the better times of my life.
Nope. I can't understand why anyone would be racist in this day and age either. Lack of understanding and a closed mind is the only reason I can think of.