One would wish this to be so, but it is unfortunately not so simple. :-/
One study seemed to show that pre-verbal children react more negatively to strangers of a different race than the one they were brought up in.
I remember my childhood fairly well.
I grew up in 60s London with a very diverse social group around my parents, and yet I remember when small being frightened by "strange" looking people like Arabs I had never seen before.
At that time I found all sorts of things frightening like dogs and loud music that I now really like. Strange things are frightening when you're little.
But soon when we moved to Canada my closest friends were in fact two Baha'i kids from a family who had fled to Montreal from persecution in Morocco (Samir and Kamal Berrada, I'd love to hear from you again!) because many of us are taught to get over this shit, or get over it naturally as we experience more of the world.
There's a natural hierarchy of positive prejudice - yourself, your immediate family, your friends and colleagues, your extended circle, each are perceived good but less and less so as you go out. Maybe your city or religion or people who support your team also get some mana from you.
But as the other person gets further away, there is suspicion. Those Chinese people, they are wanting more! I will get less, my family will get less, people like me will get less!
This is natural, but that doesn't make it right.
It's rational to fear the unknown, but it is also our responsibility to get over the bulllshit because fairness and openness to new experiences are intrinsically good things.
Young children aren't just a bit racist, they're narcissists and sorta sociopathic at times and wildly irresponsible: the cuteness masks it, but imagine an adult behaving the same way. Some kids grow out of some of these things, but most of these horrible features have to be taught out of kids.
Truthful and abundant education is as always the solution.