In this article:
http://www.newscienti...s-become-complex.html
they say:
"Although Polleux and his colleagues have not yet figured out whether the mice were smarter, he says those experiments are in the works. They also plan to put the human genes into a much closer human relative, a marmoset, and see if its behaviour is altered."
What if they have found the dominant key to the development of intelligence in humans and marmoset turns out to be extraordinary?
What if they add another copy of the gene to a human? Could they become super-intellegent?