> Berkson's paradox is a false observation of a negative correlation between two desirable traits, i.e., that members of a population which have some desirable trait tend to lack a second. Berkson's paradox occurs when this observation appears true when in reality the two properties are unrelated—or even positively correlated—because members of the population where both are absent are not equally observed.
Ineffective assholes are nonentities. Therefore all assholes worth noticing are effective, and all ineffective people worth noticing are nice.
I believe there's a name for this effect, but what it is escapes me at the moment.