That's quite a strawman argument. 'g' is a scalar that tries to measure the relatively large chunk of correlation that tends to show up on aptitude tests. On

That's quite a strawman argument. 'g' is a scalar that tries to measure the relatively large chunk of correlation that tends to show up on aptitude tests. On average, individuals who do well on one type of intellectual task tend to do well on most other types of intellectual tasks. Maybe someone is good at all forms of pattern recognition but just can't manage 3d-rotation tasks. It happens. So an IQ test isn't perfect. There isn't one true value that exists in the world that is 'g'. Many tests now break out 'verbal' and 'mathematical' IQ, but I suspect even those have a correlation > 0.5