The IQ debates are, to me, tiresome. I’m pretty high IQ, not what I consider genius level (I’ve encountered true geniuses) but just under, in the one-in-ten thousand range. Which is to say, if I’m around 10K people I expect that no one is smarter than me, unless it’s a place that selects for IQ. At MIT I’d be nothing special.
But what I’ve also noticed is that high IQ, and I’ve spent a lot of time around high IQ people and reading them, has very little correlation to being right about the sort of problems which interest me. Virtually all the high IQ economists were wrong about, well, everything, for generations. Larry Summer is extremely high IQ and he’s reliably wrong. If you want to be right about something, find out what Larry Summers thinks, and you at least know one wrong view.
IQ is very good at following rules, even very complicated ones, at seeing correlations and at pattern matching. Without judgment all IQ does is get you to where everyone who shares your priors, as the youngs say (I call them axioms or assumptions), faster.
I also believe that IQ can change over time. The more you do of something, the better you get at whatever that is. Being good at economics makes you better at economics and the types of reasoning and math it uses. (It does not make you better at understanding economies, that’s something entirely different.)
And I think that IQ is only somewhat heritable.
Right now we’re in an period where the consensus among smart non-specialist is that IQ is highly heritable and most of this comes from the result of twin studies.
The conclusion is that these studies are extremely flawed and can’t be used to make the claims made. The twins were often placed separately not immediately after birth, in fact in some cases as late as eight years old. The effects of mother’s on babies in the womb is huge (smoking, drinking, lead exposure) and that’s environment, many of them were placed with extended family and almost all were placed with middle class families similar to the ones they came from.
This debate matters. High heritability means that certain families are just superior. Bessis has a good summary of this. (The current strong case is 80% heritability.) I’m going to quote him here:
Let’s say, for example, that you are a genetically average person. How much does that affect your prospects?
- Surprisingly, at 30%, it’s as if your genes didn’t matter at all. With an average potential, you still have a decent chance of landing at the top or bottom of the IQ distribution. Actually, in this specific random sample, one of three smartest people around (the top 0.3%) happens to have an almost exactly average genetic make-up, and the fourth dumbest person has a slightly above-average potential.
- At 50%, being genetically average starts to limit your optionality, but the spread remains massive. Had you been marginally luckier—say, in the top third for genetic potential—you’d still have a shot at becoming one of the smartest people around.
- At 80%, though, your optionality has mostly vanished. It’s still possible to move a notch upward or downward, but the game is mostly over. In this world, geniuses are born, not made.
This discussion is generally omitted by hereditarians, which is unfortunate, because it is the only way to clarify the stakes. There is a fundamental asymmetry in the debate. Heritability matters a lot when it is extremely high, because it then supports genetic determinism, but for the rest of the range the exact figure has little practical significance.1
Now while Bessis doesn’t go into it, what I find even more disturbing are the racial/ethnic version of genetic IQ determinism. I think they’re largely bunk (that’s another post) but many very smart people believe them. Koreans and Chinese and Ashkenazi Jews are smarter than whites who are smarter than blacks and so on, and this is taken to explain differences in how well various countries do, not their history or their environment. Blacks are, in this view, innately stupid. It’s not that they were colonized and brutalized and that the environments they grow up in are harmful to IQ development, nope, it’s innate.
If heritability is 80%, well, they just “deserve” their fates, and there’s really nothing that can be done about it. (If IQ determines national success, which is also BS if you ask me. If it was that simple, China would never have had its century of humiliation and whites shouldn’t have ruled the world for hundreds of years when Chinese and Koreans and Ashkenazi Jews are so superior to us.)
It’s not, in this view, that Talmudic study and cultures that place an obsessive value on learning like Korea and China do, develop higher higher IQs, it’s that they start smarter.
Now, as with Bessis, I think there IS a genetic component to IQ. It’s not like it doesn’t matter at all. I just think other things matter too, and that IQ matters less than people think it does.
We may revisit this issue, though I’m unsure. For a lot of my writing career I spent a great deal of effort debunking bullshit. The problem is that it never works, most people aren’t convinced, it takes longer to debunk than produce, and there’s always more of it because the pernicious types of bullshit are highly funded. It’s hard to compete with entire think tanks spewing out garbage, and that’s the job of 90% of think tanks: what they believe is pre-determined, donors want “intellectual” arguments to back up what they already believe or what they want others to believe because it is beneficial to them.
If excellence, however determined, is 80% hereditary, then aristocracy, however defined, is justifiable. The best people come from certain genetic lineages and deserve their place in the world. Whites deserve to be above blacks, Chines and Koreans above whites, and Ashkenazi Jews are the super race. (As an aside, though not genetic, trans women blow Ashkenazi out of the water in terms of average IQ, which I find hilarious, since it means that the people who love IQ and think it’s determinitive, should love trans women.)
It also means that there’s one less reason to improve circumstances of the majority of people. The few sports will rise to their level of genetic fitness and everyone else deserves to be where they are and doesn’t need support to improve their excellence, since that’s determined by genetics not environment.
This stuff is fought over because it matters, just like the divine right of Kings mattered. It’s about justification of how society runs, or an argument to change how society treats different people. Material circumstances matter, but so do ideas. We are slaves to what we believe the world is like and what we believe people are like. We often act on those beliefs. As the sociological maxim says “things believed true have real consequences even if not true.”
Twin studies don’t show 80% hereditability because those studies were extremely flawed. That matters.
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The Interstate Bridge crosses the Columbia River, connecting Oregon and Washington State. It has a moderate length, about 1km, and was built first in 1917 and then twinned in 1958.
There has been talk of replacing it for decades, but it was reported today that the estimated cost has risen to a range of $14bn – $18bn (USD), with the new estimate so high that is simply may not be feasible to replace the bridge. Part of the eye-watering price tag is the expected timeline for construction, with the replacement taking 20 years and finishing in 2045.
By way of comparison, and barely scratching the surface, China completed the Huajiang Canyon Bridge a few months ago. The bridge is not particularly long by Chinese standards, 2.8km, but is noteworthy for being the highest bridge in the world. It was constructed in under 4 years, for a cost of roughly $300mn USD.
Nothing more really needs to be said, in my opinion.