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American IQ scores have rapidly dropped, proving the 'Reverse Flynn effect'

(www.popularmechanics.com)
256 points hirundo | 1 comments | 10 Apr 23 13:00 UTC | HN request time: 0.21s | source
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rahimnathwani ◴[10 Apr 23 16:58 UTC] No.35514446[source]▶
This blog post asserts that IQ scores didn't drop for the population as a whole, and that the drop for each individual group is due to changing composition of that group:

https://emilkirkegaard.dk/en/2023/03/new-study-didnt-really-...

For example, if the % of people who do a postgraduate degree goes doubles, it's no longer such a select group, so you'd expect the average IQ of postgraduate degree holders to go down. This doesn't mean IQ scores are going down for the population as a whole.

One more thing: why do so many papers that present charts that show how a mean or median changes over time, without also presenting charts that show how the distribution has changed over time?

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tptacek ◴[10 Apr 23 21:42 UTC] No.35517739[source]▶
It's worth looking up whose blog this is before trusting any of its analysis.
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rahimnathwani ◴[10 Apr 23 22:05 UTC] No.35517966[source]▶
I'd never heard of this person before finding this blog post via Google. So I trust the post as much as I trust any random blog post that seems to make a reasonable argument :)
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tedivm ◴[10 Apr 23 22:11 UTC] No.35518005[source]▶
You trust one of these random people enough to promote it. It's not unreasonable for people to point out that the author is quite infamous for his viewpoints.
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nostrademons ◴[10 Apr 23 22:33 UTC] No.35518200[source]▶
It's an ad-hominem (in the original sense of the word: an ad-hominem fallacy is one where the truth or falsity of an argument is determined by the trustworthiness of its proponent rather than by the content of the argument itself).

Is he right? The argument is plausible: the study measures online IQ tests. Certainly in my experience the average person online has gotten dumber in the 30 years I've been on the Internet, because Internet access has expanded and it's now the general population rather than just upper-middle-class academics. But we'd need to see comparisons vs. offline IQ tests, given to a randomly-sampled selection of the population, to be sure.

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Dylan16807 ◴[10 Apr 23 22:49 UTC] No.35518338[source]▶
It's not a fallacy to attack someone's historical reliability in making arguments.
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prottog ◴[10 Apr 23 23:15 UTC] No.35518575[source]▶
I mean, it's still precisely a fallacy. Just because someone made a stupid or wrong argument 20 times in a row doesn't make it logically follow that the 21st is also wrong, without examining that argument itself.

Of course, it's a useful heuristic to determine if it's worth your time to examine it.

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1. noobermin ◴[11 Apr 23 00:45 UTC] No.35519256[source]▶
Just a meta note, this is why fallacies are limited. Just because something is a logical fallacy, meaning it does not lead to a disproof in a deductive reasoning sense, doesn't mean people often use arguments that could be considered fallacious to disregard arguments all the time as instead they use good heuristics.

Deductive reasoning is valuable but only applicable in a small number of real world arguments, as with math it generally has to do with determining consequences of an assumption. Heuristics and just plain inductive reasoning is generally what arguments are really about most of the time.