Influence of young adult cognitive ability and additional education on later-life cognition
Or, as Stuart Richie says:
Cool new PNAS paper about potential educational effects on IQ.
Previous work: control for age-11 IQ, still find edu-IQ correlation later in life.
This paper: control for age-20 IQ, correlation is gone. Suggests education has limited influence after age 20.
IQ measurement doesn’t interest me much, but IQ development or change over time does, for ego-driven reasons. As long-time readers know, I have a very high IQ (I qualified and participated in a research study for 3SD+), but my spatial abilities are very weak and I was stymied in advanced math (past algebra 1) until, in my early 40s, I learned how to compensate using logic. I also was late to learn how I learned; my brain won’t acquire new information unless it’s tagged with all sorts of meta-data. Learning new concepts was so laborious that in my teens, I simply assumed I was incapable of learning; not until I was faced with job-related challenges did I learn how I learned. My verbal skills are extraordinarily high, although it’s hard for me to compare to others because my particular combination of smarts would have required a more thorough classical education, which I don’t have. I read 1000 wpm and can acquire extraordinary amounts of information through inference, which of course can sometimes lead me astray.
So. In 2001, I took the GRE and got 790V, 640Q, 690A. It was the last time the Analytical section was included. 640 quant was the 65th percentile that year, 690 analytical was in the 85th percentile–some logic games are brutally spatial. Anything over 700 Verbal is in the 99th percentile. I was very proud of that quant score.
In 2008, I took the GRE and got 780V, 800Q. (I’m still annoyed by the 780; if I’d focused in more, I might have gotten a double 800.) 800 Q is just the top 4% in any given year, but it’s probably more accurate to call it a top 10% score.
According to this GRE IQ estimator, my original GRE V+Q of 1340 is 99.452nd percentile, and my second GRE V+Q of 1580 is 99.993. But (forgive me IQ estimators), any IQ based on combining V+Q makes no sense, because an 800V-640Q is considerably more difficult to achieve than an 640V-800Q, so how can they be identical, IQ wise? Plus, the decimal point specificity is just goofy.
Looking at my quant score alone, in seven years from the age of 39 to 46, I jumped from just above average in math to pretty close to 2SD.
Did I get smarter, or did I simply learn how to use my existing intelligence?
The quant section of the old GRE was extremely g-loaded. I used to tutor for the test and ran into dozens of people who’d majored in college in math, knew more calculus and all that nonsense about vectors and matrix determinants and ordered ring fields than I’ll ever know, yet scored in the high 600s. Which is not to say that it wasn’t relatively easy, just that lots of smart people would occasionally miss questions because they were more about g than math competency. The new GRE combines both. I can’t find an online GRE practice test, but I did the problems on the ETS site, and I think I’d still get in the top 10%.
The GRE Math Subject test is what used to be called an “achievement” test. God, testing lingo has changed so dramatically in so little time. g is involved in the sense that a certain level of intelligence is required to learn the material. But a 120 IQ who’s taken calculus and number theory would outscore a 145+ IQ who has not.
I got 13 right out of 56. A 390. I wonder how many people get an 800 on the GRE General Quant and a 390 on the GRE Math? That’s a terrific illustration, really, of the difference between achievement and aptitude. I knew none of the number theory, only some of the stats, none of the integral questions, but all of the limit and derivative questions, and random other stuff.
Every single one of the questions I answered correctly was using math I’ve learned in the past fifteen years. Had I taken the test in 2005, I would have gotten zero correct. I took AP Calculus as a senior, remember none of it. All the math I know today is from my tutoring days or my time in teaching.
Did I get smarter, or did I simply learn how to use my existing intelligence? Here, it seems clearer than in the first case. The GRE Quant (old form) is definitely an aptitude test, which makes my big score jump odd. But acquiring new knowledge isn’t the same as having a higher IQ. Right? (asking seriously). I could do much better on this test if I studied up on integrals and 3-dimensional systems. Hold that thought.
To contrast, I took the GRE English Literature Subject Test, all 230 questions. For me, this test is diametrically opposite the GRE Math Subject test. The latter requires actual math knowledge. But the English Lit test is about 70% interpretation, 10% terminology (literary terms) and 20% content knowledge (knowing the plot of Ben Jonson’s plays, or familiarity with Matthew Arnold’s poems). I missed 56 questions, scoring a 650, in the 86th percentile (although I’ve always distrusted the scoring on English lit tests). Two of the misses were analysis and both were careless errors I’d never make in a real test. All the other missed problems were content knowledge–not anything I’d forgotten, but things I’d never learned. My English degree wasn’t terribly rigorous, but what I learned thirty five years ago, I remembered. I recognized Shakespeare’s writing in a sonnet I’d never read before–ditto Donne and Milton. I even guessed my way through Derrida and Foucault. But Wiliam Caxton, Nikki Giovanni–eh. Never heard of them. I read a lot of Faulkner short stories, but avoided his novels. And so on.
Most of the high difficulty questions (less than 30% answered correctly) were literary analysis, and I nailed them. The only hard questions I missed were three content knowledge (obscure authors) and one grammar question. The rest were in the 45-65% range, which is typical when the test is covering a broad range of material and no one knows everything. I think I could probably learn my way to a 700, but higher than that would require more interest in literature than I have.
So the GRE Math subject test requires specific knowledge, while the GRE Literature subject test allows people with high aptitude to do very well, even if their specific literature content knowledge is weak.
There aren’t many forty-something folks taking GRE Subject tests, but doesn’t it seem likely that it’s more common for someone to develop math content knowledge later in life than it is to suddenly develop excellent reading skills? Which suggests that reading comprehension, verbal ability, is more hard-wired to cognitive ability than math is. That might explain why math test scores have improved more than reading scores, generally. For all the wailing about math achievement, we do better at teaching students to improve their math abilities than we do at making them better readers.
From the study abstract: “Education does improve cognitive ability”
It does? That seems backwards to me. Cognitive ability improves educability. If all we had to do was educate people to make them smarter, I wouldn’t have this blog.
Does education actually make people smarter, or does it just teach them how to use their existing intelligence?
I have no answers, so I’ll stop here.
April 29th, 2019 at 7:51 pm
Good question. Thanks for thinking on it.
April 30th, 2019 at 4:14 am
May 2nd, 2019 at 10:26 am
“Did I get smarter, or did I simply learn how to use my existing intelligence?”
Both. There is a real “difference between achievement and aptitude” but the arrow of causation isn’t one-way. They relate in a dynamic feedback loop. This is how education has a multiplier effect.
Analogous to a student with high-g aptitude, an athlete with an innate aptitude for running fast will, with coaching and practice, achieve faster performances than an equally diligent but less gifted competitor. At the same time, the increased speed can be applied to a range of track events as well as to other sports.
Achievement, in the form of deliberate practice, begets greater aptitude.
Likewise, guided intellectual practice in a specific subject tends to be transferable, so that a concept learned in Geometry 101 is then perceived in molecules, plants, buildings, even social arrangements. The geometry is always there, but it’s unnoticed by the uneducated.
One of my favorite ER posts described the phenomenon where, in the first week of school, math students have so completely forgotten the previous year’s Algebra that their new math teacher wrongly accuses the previous year’s teacher of neglecting to teach it. Such is the nature of memory, given a summer to fade away. But all is not lost — it’s much faster to restore seemingly absent but latent memories than to teach it for the first time. Like a gifted athlete who doesn’t practice during the off-season, once track practice resumes he has a cumulative advantage, his aptitude improves incrementally from year to year.
Again: Achievement, in the form of deliberate practice, begets greater aptitude.
There are limits. The Achievement Gap is largely an aptitude gap. IQ matters. The study abstract concludes that “Education does improve cognitive ability” but teachers know from experience what modest improvements are Educationally Realistic.
Certain “key concepts” have proven to be especially powerful tools for improving my personal “cognitive ability” in a wide range of academic and everyday subjects. Learning them was an achievement that seemed to enhance my aptitude. A few favorite examples: proportions, n to the second power, Pareto 80:20.
There are countless blogs listing and explaining mental models that can be invoked to better cope with academic or real-life problems. We are fortunate to have such a wealth of knowledge, free for the taking. Thank you, teachers.
May 4th, 2019 at 7:46 pm
I agree with you that my ability to develop my achievement is based on my IQ. But the researchers didn’t seem to take that into account.
May 2nd, 2019 at 9:50 pm
I enrolled in college at 18, got my philosophy degree at 22, and got my Ph.D. in philosophy at 31. Having to teach philosophy to undergraduates massively, and quickly, improved my ability to find and articulate an author’s conclusion as well as his premises. That ability was always needed, during both undergraduate and graduate school, but never developed until I had to teach. That said, having developed that ability has made me a much better reader of argumentative texts than I would have ever thought possible.
I don’t know if you would rate that as an improvement in verbal ability or not, but if you do, then it is possible to substantially improve verbal ability somewhat late in life.
May 4th, 2019 at 7:48 pm
1. 31 is not “late in life”, you pup.
2. You are describing something similar to me, in that we both used our brain power to gain in a particular skill or subject area. Philosophyy majors have very high iq, on average.
May 4th, 2019 at 8:40 pm
FWIW, I’m 43 now. Not a pup, though maybe not a dog.
When you wrote
“There aren’t many forty-something folks taking GRE Subject tests, but doesn’t it seem likely that it’s more common for someone to develop math content knowledge later in life than it is to suddenly develop excellent reading skills? Which suggests that reading comprehension, verbal ability, is more hard-wired to cognitive ability than math is.”
I guess your point was that we should see sudden improvements in reading ability late in life as evidence that someone has learned how to use their preexisting smarts better?
I thought your point was that we shouldn’t expect to see sudden gains in reading ability late in life because reading ability is more hardwired. I was offering myself as a counterexample.
But I guess I was not a counterexample to what your real point was, and perhaps my reading ability isn’t as good as I thought it was!
May 5th, 2019 at 8:34 am
No, you understood correctly. Reading is good. Writing, not so much. You made it sound like it happened when you were 31.
I said nothing about “shouldn’t expect”. I said it was rarer, and more hardwired to cognitive ability. Meaning only quite smart people would improve dramatically in reading ability later in life.
May 13th, 2019 at 8:38 pm
‘GRE IQ estimator’–where? No link.
June 24th, 2019 at 6:32 am
It’s true that the ability to use the brain increases with practice over the years.