In my opinion this Einstein quote fits the narrative on Black slaves. There were some Black slaves who were "intelligent" during slavery, but they had to play dumb just to avoid getting attention, not to provoke "massa" to shift his focus towards them,... or playing dumb simply to avoid getting killed or beaten for being intelligent.

Playing dumb and naive was the safest strategy for intelligent Black slaves to survive in those different parts of the globe where they were enslaved.