At the other end of the spectrum, this also (partially) explains why the US Sentencing Guidelines, for no reason related to drug efficacy or impurity or anything else inherent in the drug itself, provide such vastly greater penalties for the "crack" form of cocaine than "powder" or even coca leaves. Whether justified or not, there has been and apparently remains a perception that "crack" is something those lower-class-origin, melaninically enhanced people do, while most parents in white suburbia have at least heard rumors of some kid in the neighborhood doing lines. This is only one (exceptionally obvious) example. The point is that difference acts as a polarizer to the image reflected from others.
In a both less- and more-disturbing way, I encountered the same problem in the Air Force officer corps. The "differences" involved two factors: what one wore on one's ring finger ("ring-banger" = Academy graduate) and what one wore over the left breast pocket (wings or another specialty badge—or maybe even nothing at all). The ringbanger question is a truism; Academy graduates essentially start out with a 30% promotion advantage, regardless of their actual performance or capabilities. And, leaving aside the whole "rated preference" issue, performance reports for rated officers in nonrated jobs—such as a pilot who was no longer actively flying, but instead was serving in logistics or aircraft maintenance—tended to be somewhat better than even true experts in those very same fields. This was not an obvious matter, as one had to read between the lines of the reports. One might even argue that pilots and navigators are supposed to be the elite, but that doesn't wash once one looks at the precommissioning backgrounds without knowledge of rated assignment. In a sense, this is less disturbing, because after all nobody is getting killed. Or are they, if the most-qualified leaders are not getting to lead—particularly given the glee in the pilot/navigator fraternity (the male term is on purpose) at the advantages they have merely because "the system works that way"?
In any event, the Perfesser and Professor Ribstein correctly point out a variety of "difference" that allows more explicit schadenfreude. My point is that it's far from the only one; and I can think of few people more worthy of disdain than those who rose to their prominence through disdain for others. On the other hand, I'm one of those subversive liberals, too, so I suppose I'm due for my own share…