[toomim]

You might want to read up on general intelligence, which is the well-documented phenomena that your performance on tasks like rotating shapes in your mind correlates very strongly with other tasks:

https://en.wikipedia.org/wiki/G_factor_(psychometrics)

Look at the figures in the "Cognitive ability testing" section -- see how strong those correlations are across the disparate fields of Classics, Math, and Music!

In other words, there is a mountain of evidence that IQ tests correlate with an extraordinarily broad range of aptitudes in daily life, and especially with job performance. IQ is the single most important psychometric correlate with job performance and income of any out there; it's a much stronger signal than race, gender, birthplace, or personality for instance:

"Research indicates that tests of g are the best single predictors of job performance, with an average validity coefficient of .55 across several meta-analyses of studies based on supervisor ratings and job samples."

[Apocryphon]

On the subject of psychometrics, it would be interesting to see a response to this comment from a prior discussion:

https://news.ycombinator.com/item?id=29798887