[toomanybeersies]

Intelligence isn't only influenced by genetics, but also by how an animal (human or not) is reared.

If you raise a dog in complete social isolation (not even human contact) it will be unable to cope in the outside world. The same applies to people, if a baby is raised with no interaction, they will not be capable of functioning as a normal human. There's a very well written, Pulitzer Prize winning article on one such case in Florida: http://www.tampabay.com/projects/girl-in-the-window/danielle...

I think that a convincing argument could be made that psychedelics could work to kick-start this mental expansion. There are plenty of stories of people suddenly being able to understand complex abstract concepts after using psychedelic drugs.

That's not to say that I believe that the Stoned Ape Hypothesis is "solid", I haven't done any research into it to be able to make that judgement, but it is plausible.

[n4r9]

But the SAH is supposed to explain the sudden growth in brain size, which is a genetic change in the history of the human species.