The Adventure of Strategy blog has a post that continues the discussion of Gardner's Changing Minds (discussed here.)
I think this point can't be over-emphasized:
Given that people with absolutist personalities often rise to positions of leaders in professional service firms precisely because they are often absolutist, decisive, goal orientated and driven, this means that such leaders need to be particularly careful in assessing whether their decisions are being driven by the facts of the situation, or their own possibly flawed interpretation of those facts.
This Malcolm Gladwell article supports his view:
Narcissists typically make judgments with greater confidence than other people . . . and, because their judgments are rendered with such conviction, other people tend to believe them and the narcissists become disproportionately more influential in group situations. Finally, because of their self-confidence and strong need for recognition, narcissists tend to "self-nominate"; consequently, when a leadership gap appears in a group or organization, the narcissists rush to fill it.
I discussed this problem in relation to the blogosphere here.