Say I take the quintessential representation of a subhuman; a specific person from a specific continent that is specificly linked closely to our simean "homo erectus" ancestor, and place him into a living condition where he has Mr. and Ms. Einstein - or any other stereotypical smart people of both genders - as his parents and they happen to know how to properly apply discipline to make him behave - as well as learn, properly.

Will that hypothetical kid grow up to be smart, or will he still de-evolve to his typical human condition?