I haven't read the article but I have my own experience to share.
I grew up in an essentially all white town. In the 11th grade we were joined by a black girl, she became class president in 12th grade.
Fast forward a few years and I joined the army. The first day in, my world turned 50% black. I (and my mouth) soon found ourselves getting into altercations. At my first duty station I pretty much started a race riot. We all did PT in MOPP gear the next day. I was sent to the School Of The Soldier to smarten up.
I was set out on this planet as a hateful, bigoted, racist...by my parents. I worked through all that. It took a long time. I understand that we're all people. We all deserve to be treated with common decency.