wjb3IQ differences of identical twins reared apart are influenced by education
https://www.sciencedirect.com/science/article/pii/S0001691825003853
IQ tests are very deceptive and often misused.
I don't dispute the differences in intellectual capacity between people but IQ tests are like weight lifting contests between people who didn't train to lift weights.
I don't understand why the scientific community keeps using methods that are so flawed. Perhaps it's due to my own lack of information.
The only way I could see IQ tests being a valid measurement of intellectual capacity is if participants were brought to the same level of knowledge and skills, and then were made to train for the IQ test using the exact same means, and even then cultural and language barriers must be accounted for.
Even if these twins have an identical intellctual capacity and they both had the same exact education, and same exact grades, that still doesn't mean they applied and exercised their brains in the same way for the questions of the IQ tests.
IQ tests to measuring intellectual capacity (instead of knowledge level) are like polygraphs to mesasuring truthfulness in terms of accuracy.
For measuring strength, i stand by my earlier correlation with weight lifting. If two people can dead-lift 500lbs, I only know that both participants are have reached that level of strength. What I don't know is how much effort each participant put into getting to that level of strength, which would tell me their natural muscular capacity per effort. IQ tests deceptively seem like they tell you what someone's capacity for intellect is, but they only tell you where that person is right now. Maybe that person worked hard and the score is their max, maybe the person rarely applies their brain to demanding tasks and this is their mid-level capacity.
My point is,it isn't just education or just genetics, it is also personality, effort, motivation. For all I know,someone with double-digit IQ score can work out their brain for a year and hit genius level. Choice. Can a person choose to be a literal idiot and succeed? Certainly, people choose to be incurious and ignorant all the time. Women can body-build and be as strong as many regular men for example. But simply because of a hormone difference, they have to work out a lot more than men to reach the same level of muscular strength. And men who never work out can be as weak as women who never work out.
There is also the question of brain development. Maybe the effort you put has different effect depending on age. small efforts at a young age at applying your brain might have huge impacts, where as if you're a teenager or an adult, applying the same effort might yield less results.
I mean, personally, if I tired, if I ate too much, or too little,if didn't get enough sleep, if I am distracted by something, if I'm unprepared and thus second-guessing myself, these are some of the things that throw me off wildly when taking exams. I've seen huge differences by simply getting enough sleep and calories.
There is no way that asking the same set of questions to to large population (even with control populations in place) can account for all the presumptions of the test.
The area where I see IQ failing miserably is in accounting for different types of intelligences. Like the parent commenter said, people solve the same problem differently. I'm keenly aware of this because I'm neurodivergent and I was continuously judged as poor in subjects that I liked the most and was very good at. I had to reformulate every problem and solution in a way that I understood (mostly based on spatial intelligence), leaving me at a significant disadvantage of time. And even then, those solutions were sometimes rejected, despite being objectively correct and clear in the dumbest possible way - just because it didn't follow the textbook pattern. That continued until we were in a situation where we had to solve the problems ourselves.
The reason I mention this is because I see the exact same problem with IQ tests. It emphasizes certain types of intelligences and ignores others. Human intelligence is extremely multidimensional and a single number is simply incapable of representing its overall quality. For example, there are people who score poorly in IQ, but are superhuman in remembering places and navigating their way around complex routes. Meanwhile, many high scoring ones become hopelessly lost, failing to institute or follow even simple mitigation strategies for that problem. There are situations where this determines whether you live or die, and your IQ score becomes worthless indicator of even your survival.
Afaik iq correlates highly with g-factor (scientific name for general intelligence). We don't have much better ways to measure it.
Overall, afaik, again, problem solving often needed in our society correlates with this: "general intelligence". When people say: "But there are many ways to approach a problem, many types of intelligence".
This very well may be, but data consistently shows that people having high IQ scores solve different problems better. So, contrary to popular belief, people having higher iq in general have better talent for languages, same with understanding others emotions and using it to your advantage ("emotional intelligence").
As for reframing an issue and solving it in a different way. This may be valid approach (to teach people etc). But IQ is also time-measured. If your new approach does not help you to solve previously unseen problems quickly, it is not noticably increase your intelligence.
Thus, we see consistently that people cannot really prepare for iq tests much. You only get a few points more if you prepare. Same difference as if you are sleep-deprived.
> The area where I see IQ failing miserably is in accounting for different types of intelligences.
We don't have any real evidence of "different types of intelligences". People with high IQ just tend to be better at all cognitive tasks than people with lower IQ. That's why it's considered a reasonably good measure of the g factor. People with higher IQ also have better memory recall.
While you're right that that IQ isn't the full story of a person's abilities, it's use for diagnosing people that may face challenges in a traditional learning environment well motivated. All of the examples you mention of people scoring poorly on IQ and facing challenges in school supports the use of IQ, it doesn't discount it.
> We don't have any real evidence of "different types of intelligences". People with high IQ just tend to be better at all cognitive tasks than people with lower IQ.
That would imply that a person with a high IQ score is uniformly better at every task compared to a person of lower IQ. But that's absolutely not what's observed. People show better skill levels at different tasks. A person who's bad at math may instead be a natural-born singing sensation. This is why I said that a single number is just incapable of representing intelligence. The mathematical dimensionality of the quantity called intelligence is just too high. You'll need a bunch of numbers - a vector, at the minimum. And even that can't be used for comparing people's intelligence. It can only be used for assessing someone's suitability for a particular task. Basically, IQ score is a scalar that is used to represent a vector, discarding very important information in the process.
> People with higher IQ also have better memory recall.
There are people who recite entire Shakespeare plays without understanding a sentence in it. I have also seen people who recall long derivation sequences using Maxwell's equations exactly and score well on exams, without having any clue as to what the del (∇) operator even means in practice. Needless to say, they have difficulty adapting that information to a novel situation. Memory recall is just one aspect of intelligence. There are other cognitive skills required to make that memory useful. This again goes back to my previous conclusion. A single number is quite meaningless at best and utterly misleading at worst.
> it's use for diagnosing people that may face challenges in a traditional learning environment well motivated. All of the examples you mention of people scoring poorly on IQ and facing challenges in school supports the use of IQ, it doesn't discount it.
On the contrary, it just misleads the educators to the student's real abilities. It ignores and hides the atypical talents that students possess. All it can do is to predict if the student will do well or not in generalized education and standardized testing, because they follow the equally illogical concept of using standardized pedagogy on everyone, neglecting their uniqueness. So, even if we accept your claim that the IQ score predicts their performance in schools, it means that the score has the very narrow scope of testing someone's capability to learn under a standardized curriculum. That's far too narrow to be identified as an indicator of intelligence. And even after identifying the students who are going to struggle, IQ gives no clue as to how to remedy that. All it does is put a dunce label on these students who might otherwise have done better. It does more harm than good.
> That would imply that a person with a high IQ score is uniformly better at every task compared to a person of lower IQ.
No it doesn't, that's why I said "tend to".
> On the contrary, it just misleads the educators to the student's real abilities. It ignores and hides the atypical talents that students possess.
The test simply doesn't measure atypical talents, so there's no "hiding". That's why I said the test is used to identify people who will face challenges. What happens next has nothing to do with the IQ test and everything to do with other methods of assessment that should be used. Every test has limitations that those applying the test should understand.
> That's far too narrow to be identified as an indicator of intelligence
That's why it's a (strong) correlation and not a strict equality.
Look, jumping height has been empirically demonstrated to be a good predictor of overall athletic performance, and you're coming here and saying that there exist some people without legs that can do more pull-ups than most people with legs. That's all well and good, but that doesn't somehow refute the idea that jumping height is a good predictor of overall athletic performance. It's just a complete red herring. If you happen to encounter someone without legs, then use a different test.
People with legs who don't exhibit good jumping heights but are very good at some specific athletic challenge could exist, but they tend to be good only at that specific challenge (and ones that are very, very similar). This is a completely different thing than the general factor of fitness, which is correlated with all sorts of physical abilities, just like general factor g is correlated with all sorts of cognitive abilities.
I think you are being a little bit conclusory here. There are in fact serious theories of intelligence that admit to multiple distinct intelligence factors. Mutualism is the obvious counterexample. You're arguing from what are arguably exploratory statistical correlations as if the correlation demonstrated the underlying cause. You might be right, but you're not presenting evidence for that position.