Your comment reminded me of

  intelligence is a kind of lethal mutation

comment made by Ernst Mayr.

Here [0] is Noam Chomsky's talk referencing that in it's entirety. Quite fascinating. I'll link to the video when I find some time.

Edit: Video snippet: https://www.youtube.com/watch?v=xzBqPiSpgVA

[0]: http://www.chomsky.info/talks/20100930.htm