(For other readers ,IQ is the measurement, g is the real thing.)
This seems like a misleading summary of what g is.
g is the shared principal component of various subsets of IQ tests. As such, it measures the shared variance between your performance on many different tasks, and so is the thing that we expect to generalize most between different tasks. But in most psychometric contexts I’ve seen, we split g into 3-5 different components, which tends to add significant additional predictive accuracy (at the cost of simplicity, obviously).
To describe it as “the real thing” requires defining what our goal with IQ testing is. Results on IQ tests have predictive power over income and life-outcomes even beyond the variance that is explained by g, and predictive power over outcomes on a large variety of different tasks beyond only g.
The goal of IQ tests is not to measure g, it isn’t even clear whether g is a single thing that can be “measured”. The goal of IQ tests historically has been to assess aptitude for various jobs and roles (such as whether you should be admitted to the military, which is where a large fraction of our IQ-score data comes from). For those purposes, we’ve often found that solely focusing on trying to measure aptitude that generalizes between tasks is a bad idea, since there is still significant task-specific variance that we care about, and would have to give up on measuring in the case of defining g as the ultimate goal of measurement.
This seems like a misleading summary of what g is.
g is the shared principal component of various subsets of IQ tests. As such, it measures the shared variance between your performance on many different tasks, and so is the thing that we expect to generalize most between different tasks. But in most psychometric contexts I’ve seen, we split g into 3-5 different components, which tends to add significant additional predictive accuracy (at the cost of simplicity, obviously).
To describe it as “the real thing” requires defining what our goal with IQ testing is. Results on IQ tests have predictive power over income and life-outcomes even beyond the variance that is explained by g, and predictive power over outcomes on a large variety of different tasks beyond only g.
The goal of IQ tests is not to measure g, it isn’t even clear whether g is a single thing that can be “measured”. The goal of IQ tests historically has been to assess aptitude for various jobs and roles (such as whether you should be admitted to the military, which is where a large fraction of our IQ-score data comes from). For those purposes, we’ve often found that solely focusing on trying to measure aptitude that generalizes between tasks is a bad idea, since there is still significant task-specific variance that we care about, and would have to give up on measuring in the case of defining g as the ultimate goal of measurement.