I'd be careful with both of those generalizations.
PhD's aren't necessarily smarter than anyone else. On average, PhD's -- especially at top institutions -- probably typically have above average IQs. But I'd wager a guess that the same is true for non-PhD's working for top employers (or starting successful companies).
Similarly, while it's true that PhD's have very deep knowledge about a very narrow topic, that doesn't preclude them from also having a lot of knowledge about many other topics. Especially since intellectual curiosity probably correlates better with PhD than raw intelligence.
True, I was generalizing. I was using a subject I felt most people could understand in order to relay my point.
>> "Smart" and "Knowledgable" are often used interchangeably, when really they are sets that just so happen to overlap in some places.
Ironically, the more "smart" you are, the less broadly "knowledgable" you are. PHD's are very "smart" but have narrow "knowledge". Whereas a mountainman, or someone living on their own of the land might have to have "knowledge" about many small things to survive, but might not be the brightest tool in the shed.