"the concept of intelligence has taken on a much higher place in the
pantheon of human virtues than it deserves. One of the most insidious
but also widespread errors regarding IQ, especially among people who
have high IQs, is the assumption that another person's intelligence
can be inferred from casual interactions. Many people conclude that
if they see someone who is sensitive, humorous, and talks fluently,
the person must surely have an above-average IQ.
This identification of IQ with attractive human qualities in general
is unfortunate and wrong. Statistically, there is often a modest
correlation with such qualities. But modest correlations are of little
use in sizing up other individuals one by one." - _The Bell Curve_,
pp 20-21.