You're right, it's a one-sided kind of intelligence. Maybe what Casseres said would be better phrased "people who are proud of being smart".
The fact that it's one-sided smarts, the fact that one is probably not as smart as one thinks, and the ability to imagine another person's shoes, are all life lessons that may click into place at different times for different people.
This definitely seems like a major factor to me. If I'm proud of being smart, I'll be inclined to perform smartness. And one easy way to perform smartness is by making somebody else look dumb.
The fact that it's one-sided smarts, the fact that one is probably not as smart as one thinks, and the ability to imagine another person's shoes, are all life lessons that may click into place at different times for different people.