I really hate to say this, but I find truth in the article.
I teach in a urban environment. I have observed that minority students (African American and Latinos) are often very disrespectful and aggressive to each other and those in any sort of authority.
Some of the things that come out of thier mouths make me cringe.
They are quick to resort to violence to resolve problems and rarely take the blame for thier actions (or lack thereof). Its like having 5-6 of that chick "Pocahantas" from P-Diddy's, Making The Band II, in your class all the time.
And while I know this occurs, I hate that caucausian teachers come in, see this mess and, think that they can explain away their ineffectiveness with articles like this and THE BELL CURVE.