Another original thought from me, which could be totally wrong, but I think it should be studied more. Perhaps groupthink is against it, and nobody could get funding, but I think it has an important historical impact, and it would be fun to see who had it first. I'm thinking Vikings because it is important to have iron cookware with this, and it seems to be northern. The Romans just had lead cookware. :)
Just to be PC, it is possible to be brilliant without this condition, but iron is important. Therefore, if the Mongolians brought it, then it would have been China to take over the world in nasty, nasty colonialism.
Thus, we answer the question on why China didn't take over the world. They had guns, germs and steel, or at least gunpowder, but just couldn't put it together. It took someone with brillo to do it.
ps. yes, we shall limit the benefit of Brillo to those places with lots of iron. That would explain Drake over the Armada, etc. Nappy over everyone, etc. Normally, the concept of an early death would not be an evolutionary benefit. Also, this sort of thing has to be spread fast, like Viking rape and pillage. Brain changes also explain the dawn of civilization like the Steppes horsemen. And Roman spatial skills, which may have been Egyptian. And Moorish mathematics, etc. If a population is isolated and persecuted like the Jews, then genetic things don't propagate. All of this is very un- PC.