> > My feeling is that people stumbled onto some cultural and physical
> > changes which set up specific incentives for greater intelligence -
> > bipedalism, the use of spears, fire, tools, etc. This brought us up
> > to IQ 100. But that was smart enough for these purposes. IQs of
> > 130 or 150 wouldn't make someone any better at using these tools.
Take a choice between losing say 40 IQ points, or losing an arm (where somehow you didn't die of blood loss/infection). What would be worse for a "human in the wild" (ie: hunter gatherers, although I suspect high tech civ is actually the native environment for humans).
I'd lean toward the IQ being far more detrimental. With high IQ and one arm, you could be the leader, and you could invent interesting ways of getting along. With two arms and brain damage, you are a pawn in someone else's army.
Emlyn, monkey boy