Frequently, the first question I get is: How do I know that the guy was 'being' racist. 'Practicing sociopathic-racism' is not the same as 'being racist'. Bluntly, the point isn't to identify his state of being. Id'ing the practice is much easier and helpful in starting a path to addressing the dangerous actions. Understanding the effort, the situation, and the context helps explain the feeling and the conclusion about what was being practiced. A better example is found in replacing the question with another: How do you know that someone is being a smart ass. That's also not the point, determining this person's being. It's the practice of it- what those actions happening at that moment look like from a history of seeing them in action, in context and application. Like experiencing someone practicing something: a sport, singing, dancing. The actions, the context, the application will all look very familiar and distinct after seeing them over and over ( even if you've never whipped your leg in any direction to a rhythm). It's especially easy when the practice of one thing (ball room) is so very different from some other practice (pop locking). With more exposure you can them more easily discern when someone is practicing swing dancing and not bebop. Experiencing someone practice racism looks, feels, sounds very different from experiencing someone practice anti-racism. For someone who hasnt seen it practiced in it's multitudes, it can be just summed up as rudeness. It's not so much as 'Takes one to know one' as much as its I've seen it practiced for a lifetime and that practice of it looks perfect.