I personally believe IQ is a fairly good predictor of intelligence the way people in (at least American) society think about it. This study attempts to prove that high IQ is good for most jobs. What it doesn’t prove is the high end of the spectrum where someone of 120 IQ compares with someone of 140IQ in extremely high level jobs. My experience is that creativity trumps IQ in most cases where people are considered generally intelligent. The people that really are viewed as most successful typically have a high or very high IQ, but are always very creative.