I dimly recall hearing some discussion on this back in college where it was supposed that it's true up to a point, but with very very high IQ, not so much. The main problem with being scientifically confident with this at the time was the low Ns involved.
Florence, our psych class matriarch (40 yo, finally getting to go for her degree) put it this way:
"Very bright people join Mensa. Very, very bright people join Mensa Squared. Very, very, very bright people join the Rotarians and the Optimists and their Church Choirs."
Nobody dared argue with Florence.
Terry, 230RN