After reading much of this thread, I have to say that racism is a more complex phenomenon than I had previously realized.
I had assumed that racism was just bigotry based on race. And bigotry is essentially just the act of psychological scapegoating. It's the psychological act of projecting one's own fears, anger, and resentments onto someone else (usually a stranger) so as to externalize it, and falsely 'transcend' it, in oneself. It's a way of raising one's image of oneself up by slandering someone else. And it's not only dishonest, it's harmful to everyone, especially to those people being scapegoated and slandered.
But there seems to be other, lesser versions of it that do not involve deliberate scapegoating. Such as the very real fear we might feel in reaction to our psychologically 'profiling' others. The fear we might feel, for example, when confronted by someone who presents a violent, criminal, or otherwise defiant demeanor. I lived in inner city Chicago for many years, and the street gangs there had certain colors that they would wear so they could identify each other. They also had special hand signs and graffiti symbols they used to mark their territories. And naturally, if I were confronted with a young black or hispanic male wearing those colors, flashing those signs, or I saw gang graffiti on the walls around me I would immediately consider myself to be in danger. And this wouldn't be because I wanted to scapegoat them, to make myself feel superior. It would be because because they are violent and dangerous people who want me to fear them. They want society to 'think badly' of them. And any cop working in the inner city would not last long if he didn't understand and react accordingly to these 'profiles'.
There is also a natural fear that people have to other people who are 'different'. And that's simply because we humans survive and thrive by knowing how to control and manipulate our environment, and other human beings are our greatest threat. So it's important to us that we feel we know how to interact with others without danger.
But if those 'others' are significantly different from us, we become nervous because we feel we don't understand them well enough to predict how they will behave if we have to interact with them. And this fear, too, is not based on a desire to scapegoat anyone. Nor is it totally unreasonable (though it may well be unwarranted). It's simply a natural human reaction to the "strangeness" of some other humans.
And it would be quite difficult for us to differentiate the projection and scapegoating of bigotry from these other forms of natural fears and resentment that occur within ourselves, and within others. When in fact they are very probably intertwined. Which explains why racism is such and difficult and intractable human character trait, and flaw. And also why we so rarely are able to recognize it in ourselves.