Quite frankly speaking and acting as if you are from the upper crust is itself a criteria for success. It might be fine to say that this is not a skill, but people can definitely tell and they select for it.

I spent most of my time in government, and I was quite shocked in private industry how enthusiastically nearly everyone had taken to the class divide. It was a bit like A Brave New World. Even when resenting it, the lower class totally bought into the mythos of the upper class. It was very clear I would never be an executive at my company, but at the same time, my particular company was riddled with incompetent and corrupt executives.

I didn't feel or sound like one of them, and I refused to lie or bullshit. And every one of them could tell, and it forever marked me as an outsider.