Does IQ Really Predict Job Performance? -- published in Applied Developmental Science 2015 Jul 3; 19(3): 153–169 -- concludes (among other points) that:
Supporters of IQ testing have been quick to point to correlations
between IQ and job performance as evidence of test validity. A closer
look at the data and results, however, suggests a rather murkier
picture.
Hundreds of studies prior to the 1970s reported low and/or
inconsistent correlations between IQ and job performance.
The claim that the IQ-job performance correlation increases with job
complexity is not born out in more recent studies.
This supports the claim that the topic has been widely-studied, if that's what this question is trying to get at.