I've seen some those studies and they confuse racism with discrimination against a "thug" stereotype that far too many young blacks embrace. IMO, the issue isn't related to the fact that they are black, but rather that what most people notice the most about young blacks is the stereotype that they seem to love. When someone sees a young black guy wearing "gang" style clothing and with an attitude to match, they do pull back. See that enough and they start equating that same attitude with all young blacks.
The problem looks like this:
Joe citizen sees a young black person.
The young black person is acting like a stereotypical "thug".
Joe citizen sees another young black person.
That young black person is acting like a stereotypical "thug".
Repeat a dozen times or so and what happens is that the idea of young black person equaling a "thug" gets reinforced, regardless of the person dress or behavior.
Keep in mind that I learned this from a guy who's an ex-Law enforcement and is black (nicest guy you ever wanted to have your back since he's considered an actual mountain in several states [muscle, not fat]). Tom told me that the problem is that people learn things and what they are learning about young blacks these days has far more negative than positive. The problem is twofold, first of all people should be judging others solely on their character and not their manner of dress, secondly, if you want respect, act respectful.