IQ decline dysgenics (are IQs really falling?)

As an “IQ junkie”, anything about IQ is going to pique my interest. I saw this going viral: American IQ scores have rapidly dropped, proving the ‘Reverse Flynn effect’ . I don’t think it necessarily proves what it purports to claim. It’s possible:

-The Fynn Effect never existed. The existence or lack thereof of the Flynn Effect is debated.

-Purported IQ declines from 2006-2018 on online IQ tests cannot be readily generalized to the entire US population, or as a harbinger of a new trend. It’s possible that the long-term trend of IQs rising is still intact, but we would also expect some years in which IQs are falling (secular vs cyclical) within this long-term trend.

-Even if it does signify that people are getting dumber, there are more total smart people overall even if average IQs are falling slightly. It would seem as if the US economy has benefited from a windfall of high-IQ immigrants (Russian Jews, Slavs, Orientals, etc.) to compensate for dysgenic demographic trends otherwise. This is why the US economy pulled so far ahead of Europe starting in the early 20th century, and then accelerated even more so starting in 2009 with the FANG tech boom, and then post-2020 during and after Covid. It’s also part of the ‘great bifurcation’ seen everywhere in the US of things getting dumber and smarter at the same time, such as kids taking calculus at earlier and earlier ages, but at the same time juxtaposed with dumbing-down elsewhere (such as schools ‘banning‘ algebra).

-As Emil notes, grade or credential inflation can play a role. If we imagine due to grade inflation that the minimum IQ to graduate college has declined from, say, 110 to 100 from 2006 to 2018, we can expect the mean IQs of both high school grads and college grads to fall even in the absence of a reverse Flynn Effect.

For example, in 2006, let’s assume college grads have a mean IQ of 115 and high school grads have a mean IQ of 105. Then, in 2018, high school grads with IQs in the 100-110 range are able to finish college due to grade inflation, which lowers the mean IQ of college graduates to maybe 105. Consequently, the mean IQ for high school grads falls too, maybe to 97 or so. But this would cause an increase in the percentage of college educated adults in the US, which is corroborated by the data:

-Notably any mention of race or immigration is absent from this study. These variables are not immaterial.

Overall, I think it’s hard to conclude either way.

1 comment

  1. Flynn Effect is just better data compression, where the increased “human intelligence” is “stored” in the form of better metaphors and memes.

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