> IQ is literally the strongest predictor of job performance across every category. ...This result has been replicated by industrial psychology resource again and again over decades.
Do you have source(s) for that?
edit: The top google scholar result for "IQ predict job performance" is Does IQ really predict job performance? (2015), a fascinating paper which discusses a lot of the relevant issues and their history.
https://www.tandfonline.com/doi/pdf/10.1080/10888691.2014.98...
"To supporters of IQ testing...the picture seems crystal clear. Job performance must be a good test of individual differences in intelligence. IQ test scores (or their surrogates) correlate significantly with ratings of job performance. As a result, IQ tests must be a valid test of intelligence.
What we actually have are scores from a predictor of nebulous identity correlated with ratings for a seemingly discrete construct that is turning out to be equally slippery. In other words, very strong conclusions are seemingly being drawn from correlations between two under-specified constructs. This makes interpretation of the (modest) correlations extremely difficult. In primary studies such correlations have generally left over 95% of the variance unexplained. Even the typical meta-analytic correlation of 0.5 still leaves 75% of the variance unexplained. This does not seem to us to constitute grounds for asserting test validation so strongly."
Their "summary of the main points":
"1. Much in developmental theory, and psychology in general, depends upon the validity of IQ tests. 2. In the absence of agreed construct validity this has weighed heavily on indirect validity using correlations with criterion outcomes among which job performance has a special status. 3. Hundreds of studies prior to the 1970s reported low and/or inconsistent correlations between IQ and job performance. 4. These correlations have been approximately doubled using corrections for supposed errors in primary results and combining them in meta-analyses. Such corrections have many strengths, theoretically, but are compromised in these cases by the often uncertain quality of the primary studies. 5. The corrections to sampling errors, measurement errors, and to range restriction have required making a number of assumptions that may not be valid and have created a number of persistently contentious issues. 6. The claim that the IQ-job performance correlation increases with job complexity is not born out in more recent studies. 7. A range of other—including noncognitive—factors could explain a correlation between IQ and job performance, and even constitute part or all of the enigmatic "general factor." 8. There remains great uncertainty about the interpretation of IQ-job performance correlations and great caution needs to be exercised in using them as a basis for the validity of IQ tests and associated concepts."