Eric Raymond wrote a post about how he realized that Bush actually is smart even though he's inarticulate. I commented:
Dubya's an example of a different evolutionary psychology strategy. The people we usually think of as "smart" win dominance struggles by displaying better verbal ability. Others (call them "jocks" for this purpose) choose the alpha male by a contest of physical prowess. Now fights are dangerous even to the winner so they'd rather settle it by threat displays than blows. But that creates the danger that they'd yield to a bluffer when they could have won the fight.
Dubya is optimized for that situation--someone who's so incredibly BAD at verbal communication that he obviously can't pull off a bluff. So the other jocks take seriously any threats he makes and he wins without a fight.
The verbal types watch this incredulously because they *know* they can out-argue this guy any day of the week, so how can he be alpha? It's because all the jocks are convinced he can beat them up and they want to back the winner.