Well, I don't know about these tests, but I'm betting if you think about this you'll actually have noticed this yourself. But there are only a handful of personalities, people are like Npc's in a game there's only a couple. But to make things traverse a few quirks are added here and there. Have you ever met someone whom look's like someone else you know, and they have similar mannerisms, talk the same, but are different. But they always remind you of the other person? If you really pay attention you'll notice what I'm talking about. Every once in a while you'll notice someone who's not a cookie cutter personality. I'm curious if people like Alexander the great, and other epic people throughout history had the same personality, just slightly different because of environmental input.