[throwaway37585]

“Research suggests that the SAT, widely used in college admissions, is primarily a measure of g. A correlation of .82 has been found between g scores computed from an IQ test battery and SAT scores. In a study of 165,000 students at 41 U.S. colleges, SAT scores were found to be correlated at .47 with first-year college grade-point average after correcting for range restriction in SAT scores (the correlation rises to .55 when course difficulty is held constant, i.e., if all students attended the same set of classes). [1][2]”

[1] Sackett et al. 2008

[2] Frey & Detterman 2003

[learc83]

>g scores computed from an IQ test battery and SAT scores.

That's the problem IQ tests can be gamed as well. There's ample research showing you can study to improve your score on IQ tests.

[throwaway37585]

And yet...

“Psychometricians generally regard IQ tests as having high statistical reliability.[9][56] A high reliability implies that – although test-takers may have varying scores when taking the same test on differing occasions, and although they may have varying scores when taking different IQ tests at the same age – the scores generally agree with one another and across time.”

“Clinical psychologists generally regard IQ scores as having sufficient statistical validity for many clinical purposes.[22][57][58] In a survey of 661 randomly sampled psychologists and educational researchers, published in 1988, Mark Snyderman and Stanley Rothman reported a general consensus supporting the validity of IQ testing. "On the whole, scholars with any expertise in the area of intelligence and intelligence testing (defined very broadly) share a common view of the most important components of intelligence, and are convinced that it can be measured with some degree of accuracy."”

[learc83]

None of what you cited has anything to do with sustained practice.

IQ tests are generally accurate across a large population because very few people are practicing them, not because practice doesn't improve scores.

If you provided widespread incentive for people to practice IQ tests like colleges do for the SAT, they would cease to be an accurate measure of intelligence.

[throwaway37585]

You admit IQ tests are generally accurate, and I showed that SAT scores are strongly correlated with IQ. Thus SAT scores are also generally accurate. So what’s your point?