University of Cambridge Cognitive Ability Test

I still do not understand why we are wasting scientific resources trying to stack rank humans on arbitrarily defined concepts like cognitive ability or intelligence.

After over a century of psychometric research in cognitive abilities and intelligence, what do we have to show for it? Whose life has actually improved for the better? Have the benefits from such research, if any, outweighed the amount of harm that has already been caused?

Psychometrics has clear value. Cognitive ability predicts academic/job performance (Schmidt & Hunter 1998, Psych Bull), and standardized tests reliably forecast college outcomes (Kuncel, Hezlett & Ones 2004, Science). Conscientiousness adds further predictive power (Poropat 2009, Psych Bull). The science is robust. The issue is the discomfort it causes, not lack of benefit or predictive power.

Intelligence testing is not widely used in employment hiring, despite many attempts. Why is that?

Of course it is[1]. Every single method used to screen a candidate is essentially testing for general mental ability. Being admitted to an Ivy League school is basically an IQ test. Interviews are basically IQ tests. Employers want to hire smart people. The fact that his is even a debate is crazy.

[1] https://psycnet.apa.org/record/1998-10661-006

Your definition of an IQ test seems to be so vague as to be meaningless.

Last time I passed a job interview, on several rounds of interview not one was about general intelligence, or general knowledge, or general anything. It was about my ability to solve the kind of problems they were solving and I had some experience solving. Last time I failed a job interview it was because of a bad culture fit.

I have not looked at the numbers, but I would suspect Ivy league admissions to be more correlated with wealth / geography than possibly anything else, but you probably square that with a belief that intelligence is hereditary as wealth is.

IQ tests measure the ability to solve quickly some abstract problems in an exam-like situation. There is certainly a use case for that, but thinking it captures the whole of "cognitive ability" is like thinking that duolingo captures the whole of litterary.

By the way, anytime one can't understand why $DEBATED_TOPIC is debatable should be an indication that one should switch to a slower though process.

In practice, intelligence tests don’t depend on the specific questions asked. If you let a group of people generate their own questions, pool them together, sample randomly, and then rank scores, the same individuals would tend to rise to the top. This is because people with higher general cognitive ability perform better across virtually any cognitive task, a phenomenon first documented by Spearman (1904) and repeatedly confirmed in psychometrics research (e.g., Jensen 1998; Deary 2012).