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?

Because the supreme court ruled that it's racist to do so

https://en.wikipedia.org/wiki/Griggs_v._Duke_Power_Co.

No, the Supreme Court ruled that you have to have a concrete business reason for implementing a test that is disproportionately likely to favour one ethnic group over another:

> The touchstone is business necessity. If an employment practice which operates to exclude Negroes cannot be shown to be related to job performance, the practice is prohibited.

Isn't that the same thing? Basically a business that believes hiring is better using IQ is not able to do so since the supreme court ruled that is racist.

No. A business that believes hiring is better using IQ is able to do so if they can show that it has a relation to job performance.

The problem is that that is very easy to prove... but really hard to convince a modern judge of.