Ask HN: Why are technical interviews legal while IQ tests are not in the US?

IQ is a touchy subject in the states

Problem solving in technical interviews is closer to case study interviews than straight IQ testing. It is applied competence under pressure. Case study interview questions and multi-hour deep dives are very common on the non-technical side as you get into more experienced roles.

IQ tests are legal to the extent that they apply to the job at-hand. From the Civil Rights Act:

> nor shall it be an unlawful employment practice for an employer to give and to act upon the results of any professionally developed ability test provided that such test, its administration or action upon the results is not designed, intended or used to discriminate because of race, color, religion, sex or national origin

https://www.eeoc.gov/statutes/title-vii-civil-rights-act-196...

Though understandably, a lot of people in the United States see this as a risky heuristic given the IQ test's history as a discriminator of race and national origin.

In 2000 I applied for an enumerator job for the U.S. Census where they had us take what was basically an I.Q. test of about 30 questions or so and they called people back in order of how they scored. It was one of the best teams I ever worked in.

> Doing well on this activity is probably highly correlated with having a high IQ.

Most possibly. That claim can be made stronger if you had a source to eliminate any doubt of that.

> However, this is not how people work in practice and so the work may not need such a high IQ.

There you go.

Whenever the interviewer asks anyone to do the algorithms challenges and puzzles, there is a very high chance that they do not use it in practice and they just Google'd interview questions on the spot.

In reality of their own work, they themselves are googling, copy-and-pasting, using StackOverflow, GitHub issues and ChatGPT'ing their way to 'solving problems'.

So to your great question:

> So why are such technical interviews legal in the US if IQ tests are not?

The reason is, almost everyone thinks they are a 'Tech / AI company' like Google but doesn't know what they are looking for and they mimic what Google does. Hence the pseudo-IQ test / interview questions loophole.

What's wrong with tech interviews? They have flaws, but I think they do a decent job of filtering out bad candidates. If you can solve basic problems under adverse conditions, you probably grasp the basics well enough for the job. That's better than someone who doesn't grasp the basics.

Testing somebody on a test that correlates with IQ that correlates with technical ability that correlates with job performance is not okay, because of the levels of indirection passing through a very abstract space (a Bayesian coefficient of 'smartness'), which has historically been used discriminatorily against groups that it would otherwise be illegal to discriminate against.

Testing somebody on a test that correlates with technical skill that correlates with job performance (and maybe IQ) remains within the easy to defend realm of the concrete.

Good technical interviews are generally looking to see _how_ you approach solving a problem more than whether you can ace it. There are also soft skills being tested like whether you can collaborate, communicate your approach, test assumptions rather than getting caught in a rabbit-hole, etc..

There may be some correlation with IQ as you propose (correlation isn't causation), but I can state unequivocally that there are people who have nailed tech interviews that had lower IQs than people who ... did less well.

Ultimately the premise seems shaky here - technical interviews are testing work-specific competence, not some outmoded and arbitrary "intelligence" metric which (to paraphrase the inventor) _was only ever supposed to be used to test for people who needed extra support_

Or to put it another way: if I'm hiring a carpentry apprentice, I probably want to know if they're likely to hit me or themselves with a hammer.

That likelihood might generally correlate with IQ, but pretty sure there'd be both great and terrible candidates across the full spectrum

IQ is an attempt to measure human intelligence.

Technical interviews while correlated to intelligence are not trying to directly measure it. In theory one should be able to improve on their technical abilities regardless of their intelligence. However, they can not increase their intelligence (at least not dramatically).

I think it's fair to say that technical interviews are simply fairer for this reason since someone can work at being competent at a specific set of skills while not being able to work at being more generally intelligent (as measured by IQ).

Given performance on IQ tests tend to correlate to one's social economic background, I believe the political motivation isn't just about what's in the best interest for individual job seekers, but also because IQ tests could be used as way to screen out otherwise competent candidates that come from "undesirable" social economic backgrounds.

Personally I think IQ is underrated as a general measure of intelligence and is a very good indicator of potential competency at any given skill. In my experience high IQ individuals are simply nicer and more interesting people. They're also able to pick up things significantly faster where IQ differences are large. For all its flaws if I could only rely one data point for a hiring decision (at least for a technical role) it would be IQ.

I say this as someone who generally scores poorly in high quality IQ tests. The only exception to this is if I'm given a non-verbal IQ test like Raven's progressive matrices, then I'll typically score in the top few percent of the population. For this reason if you set someone like myself a technical test I'd probably pass it, but this would be unfortunate because you'd then find out I'm unable to communicate and have barely functioning memory. In which case you'd probably wish you hired someone who preformed worse on the technical test but had a higher IQ. And this is why IQ is so useful – it tends to correlate with broadly with the type of person you'd want to hire.

I just literally spent the weekend reading about IQ testing in the US and so many legal cases, which was so painful to read

In short, the sum of what I read was that IQ tests seem to be at least somewhat biased in favour or well off native English speakers - and this has resulted in discrimination of various sorts towards minority groups.

I can imagine a technical interview is more about showing you have the skills that they’ve specifically asked for in the job advertisement.