Crémieux Profile picture
Sep 5, 2024 13 tweets 5 min read Read on X
How bad are Richard Lynn's 2002 national IQ estimates?

They correlate at r = 0.93 with our current best estimates.

It turns out that they're really not bad, and they don't provide evidence of systematic bias on his part🧵 Image
In this data, Lynn overestimated national IQs relative to the current best estimates by an average of 0.97 points.

The biggest overestimation took place in Latin America, where IQs were overestimated by an average of 4.2 points. Sub-Saharan Africa was underestimated by 1.89 pts. Image
Bias?

If you look at the plot again, you'll see that I used Lynn's infamously geographically imputed estimates.

That's true! I wanted completeness. What do the non-imputed estimates look like? Similar, but Africa does worse. Lynn's imputation helped Sub-Saharan Africa! Image
If Lynn was biased, then his bias had minimal effect, and his much-disdained imputation resulted in underperforming Sub-Saharan Africa doing a bit better. Asia also got a boost from imputation.

The evidence that Lynn was systematically biased in favor of Europeans? Not here.
Fast forward to 2012 and Lynn had new estimates that are vastly more consistent with modern ones. In fact, they correlate at 0.96 with 2024's best estimates. Image
With geographic imputation, the 2012 data minimally underestimates Sub-Saharan Africa and once again, whatever bias there is, is larger with respect to Latin America, overestimating it.

But across all regions, there's just very little average misestimation. Image
Undo the imputation and, once again... we see that Lynn's preferred methods improved the standing of Sub-Saharan Africans.

There's really just nothing here. Aggregately, Lynn overestimated national IQs by 0.41 points without imputation and 0.51 with. Not much to worry about. Image
The plain fact is that whatever bias Lynn might have had didn't impact his results much. Rank orders and exact estimates are highly stable across sources and time.

Want to learn more? See:
See this too, and note that it depicts rank correlations:
See this as well, on how very diverse data produces the same results:
And finally, see for the source of our current best estimates.sebjenseb.net/p/most-accurat…
It also might need to be noted: these numbers can theoretically change over time, even if they don't tend to, so this potential evidence for meager bias on Lynn's part in sample selection and against in methods might be due to changes over time in population IQs or data quality.

It might be worth looking into that more, but the possibility of bias is incredibly meager and limited either way, so putting in that effort couldn't reveal much of anything regardless of the direction of any possible revealed bias in the estimates (not to imply bias in estimates means personal biases were responsible, to be clear).
Some people messaged me to say they had issues with interpreting the charts because of problems distinguishing shaded-over colors.

If that sounds like you, don't worry, because here are versions with different layering:
Image
Image

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More from @cremieuxrecueil

Jul 2
I've seen people mentioning that Europe's heat-related death issue is larger than American gun violence—true!

But people neglect saying how many heat-related deaths America has.

Approximately 1% of what Europe does even though America is hotter and Americans are less healthy! Image
Those factors mean Americans are more at-risk for heat-related deaths, even after accounting for Europe being a little older than America.

So let's be clear:

Europeans die from heat at relatively high rates; Americans survive it with technology. Image
Image
What technology?

It's the terraforming technology of air conditioning.

Install A/C and the heat-related deaths will mostly disappear, if Europe can keep their grid operational. Image
Read 7 tweets
Jul 2
What happens when scholars get canceled?

They end up publishing fewer papers and they receive fewer citations.

In other words, scientific productivity falls🧵 Image
Tons of scholars have been cancelled in recent years.

That is, they've received professional backlash for expressing views that people deem "controversial, unpopular, or misaligned with prevailing norms." Image
Cancellations happen outside of academia, but it's very bad in it.

Large portions of the academy dislike the freedom of speech. Many of those free speech opponents have high agency and the clout to cause material harm to people they dislike = particularly bad cancel culture. Image
Read 13 tweets
Jun 28
You must pick one:

Double the productivity of the bottom 20% or double the productivity of the top 1%:
Double the productivity of the bottom 40% or double the productivity of the top 1%:
Double the productivity of the bottom 60% or double the productivity of the top 1%:
Read 7 tweets
Jun 27
Phenotyping is the vast, minimally-explored frontier in genome-wide association studies.

Important thread🧵

Briefly, phenotyping is how you measure people's traits. Measure poorly, get bad results; measure well, get good results.

Example? Janky knees. Image
The janky knee example refers to osteoarthritis, the most common form of arthritis, which occurs when the cartilage between bones is worn down, so bones start rubbing against each other.

This ends up being very painful. Image
Everyone with this condition isn't necessarily diagnosed with it.

This is especially true for men, who tend to just ignore this (and many other conditions) more often than women do.

This is, in a word, annoying, because it means that if you study it, sampling is likely biased. Image
Read 35 tweets
Jun 25
ADHD is a condition that's suffered from diagnostic drift: it's been defined more leniently over time, so more people are getting diagnosed.

One way to see this is to look at the benefits of taking ADHD medication. As prescription rates increased, the benefits have declined. Image
Another way to understand diagnostic drift is to look at the factors that promote it.

For example, school accountability laws lead to more diagnoses and, as a result, more psychoactive drug prescriptions.

Schools are pressured by law into making this happen. Image
An even more direct way to understand ADHD's diagnostic drift is to look at what types of diagnoses happen over time.

The increase has been more about non-severe ADHD than clinical ADHD. In other words, people with less and lesser symptoms are getting diagnosed. Image
Read 4 tweets
Jun 24
I have a story to break.

Columbia is still practicing racially discriminatory admissions in defiance of the Supreme Court's ruling in SFFA v. Harvard.

Newly-leaked data shows they still prefer less-qualified Blacks and Hispanics over more-qualified Asians🧵Image
Columbia has made a big show of "complying" with SFFA v. Harvard by noting that their 2024 batch of admits involved slightly less discrimination:

Fewer Black and Hispanic students, more Asian students.

That's what should happen, because Asian students tend to perform better.Image
But, with this leaked admissions data, we can see that race still predicts admissions.

With fair admissions, race should not have a significant effect, and it should not be directionally consistent.

And yet, in this data, it's clear Columbia still discriminates against Asians. Image
Read 14 tweets

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