Great question. My primary point was that the IQ scale and absolute intelligence aren’t the same things, and people often assume they are (this article’s premise, for example), or even worse many people assume that absolute intelligence goes up exponentially along with the rarity of the IQ ranking. Height was simply an example of how there’s an obvious discrepancy between standard deviations and the underlying absolute metric; the rarity of one person’s height says literally nothing about how tall they are, and yet people assume without any justification whatsoever that the rarity of someone’s IQ score does say something about how smart they are. All human physical characteristics have a relatively narrow range, and they don’t increase exponentially. Running is another example - Usain Bolt can run faster than 99.9999% of people, and yet he’s only 10% faster than the average competitive sprinter and maybe ~50% faster than the average person not trained in running. You’ll see similar distributions with weight lifting. The number of brain cells doesn’t grow without bound - we all have similar amounts. The construction of the brain cells and the structure of the brain isn’t wildly different from person to person. Most skulls are approximately the same size. Most eyeballs and ears and arms and legs all vary by about the same amount height and head size varies. So, there really is good reason to start with the hypothesis that raw biological cognitive capacity and speed don’t vary by a lot more than height does, and - importantly - that they all top out at the upper end of the distribution.
> Did you mean to imply the ratio between intelligence of someone with IQ of 100 and IQ 180 is smaller than a factor of 1.8, or did you mean something else?
I meant that from the start, assuming the factor is 1.8 is a very bad assumption. That’s simply not how standard deviations work. Yes, please consider the possibility that the cognitive capacity of IQ 180 is less than 1.8 times more than that of IQ 100. If intelligence has a similar distribution to other physical characteristics, then difference between the mean and the first standard deviations is much larger than the difference between the first and second standard deviations. Translation: the jump from 130 to 160 is probably much smaller than the jump from 100 to 130. And going from 160 to 190 IQ, there is likely a negligible, unmeasurable difference in absolute intelligence. This is the opposite of the popular conceptions of IQ, right?
> The evidence that intelligence can be trained is that every metric of intelligence ever invented is consistently going up
Again, you are confusing raw intelligence with psychometric tests. Yes you can train for an IQ test. No, you cannot train intelligence. ‘Intelligence’ in this context, the kind we are discussing, is defined as the biological component of cognitive capacity that cannot be trained. Intelligence and skill are two different things, go ahead and google that question. The fact that IQ tests are not currently able to differentiate between intelligence and skill is a well known shortcoming of IQ tests, and that relates directly to my initial point: IQ is not a great measure and assuming that IQ score and happiness would have a correlation anywhere near 1 is a very bad assumption.
> Sure, you can always claim that all of those are skills separate from intelligence
Yes, yes I can, since it’s true. Therefore, given that fact, the question you asked is one for you to ponder and answer. What is the source of the claim that being better at one “automatically makes you better at all the others”? Does taking IQ tests give you more brain cells or increase your cognitive speed? You’re hand-waving this training argument and ignoring the fact that people who train for IQ tests still top out and hit a wall regardless of the amount of practice, they don’t increase their scores indefinitely. If intelligence could be trained, why isn’t everyone a so-called high IQ genius?
> Why didn’t you correct me back then?
Hehe I don’t need to argue every wrong thing you say, and doing so doesn’t make for good conversation. Your assumptions only reflect on you, not me. I assumed you’d eventually re-read the comment you replied to and figure out that using 20% in your argument was straw man given that I actually gave an example of a 50% variance in height in that same comment, and that I only used height as an analogy, not a claim about intelligence. When people seem to misunderstand my comments, whether it’s a mistake or intentional, I prefer to try to clarify my broader intent and not nitpick every word. Rebutting every single thing tends to escalate arguments and send the impression that you’re reflexively arguing rather than thinking, and seeking disagreement rather than agreement. I try to follow the HN guidelines, and I’m by no means always perfect, but they are pretty good guidelines, right?
> Hehe I don’t need to argue every wrong thing you say
No you don't. But if it's a central point of my argument, and ESPECIALLY when you throw it in my face later on that I based my argument around it - it feels like I wasted a lot of time and effort for nothing, and makes me wonder how much else of what I'm saying is a similar waste of time because you refrained from telling me I'm wrong about something else similarly important. Makes me hesitant to put too much effort into this conversation.
> I meant that from the start, assuming the factor is 1.8 is a very bad assumption.
I agree with the literal words - exactly 1.8 is almost certainly the wrong answer. But where we differ is that you believe it's less than 1.8, and I believe it's more than 100. A person with IQ 180 is likely two orders of magnitude more intelligent in absolute terms than someone with IQ 100. On the other hand, someone with IQ 60 is only marginally less intelligent than someone with IQ 100. It's because intelligence is not a physical attribute, but closer to a skill.
Usain Bolt is only a little faster than a typical adult because speed is capped by the physical limits of the human body. Intelligence is not, because it's not a physical attribute.
And if you want to continue insisting it is a physical attribute, I'd like to ask you for some evidence that it's actually the case, rather than assuming it a priori. As far as I know, neither brain size nor the number of neurons nor synapses is correlated with IQ.
> it feels like I wasted a lot of time […] Makes me hesitant to put too much effort into this conversation
Hahaha, buddy, this is very funny. Lack of effort is what caused your problem in the first place. I’m super surprised you’re digging in your heels on this. If it was me, I’d drop it, since it’s not a good look, but suit yourself. You got something wrong. So what? Own it. Fix it. It isn’t my responsibility to correct you, it’s yours. You did indeed waste a tiny little bit of time by arguing and jumping to conclusions before reading carefully. ;) And that’s okay, which is why I ignored it. I’ve wasted time making mistakes too. There’s nothing wrong with making mistakes. How you deal with mistakes is revealing though, and blaming others for your mistakes isn’t typically very productive here, even if some politicians seem to get away with it. :P I do honestly appreciate that your previous comment tried to de-escalate a bit. Asking what I meant was a positive step, and asking that earlier would have saved you some time. Always assuming good faith and making sure you read carefully and understood everything is a good thing to learn to do on HN, that’s what the guidelines are trying to hint at. I have learned this lesson myself the hard way, multiple times, FWIW.
> Intelligence is not, because it’s not a physical attribute
Well okay this is our core problem. We have been talking about different things. And, I need to concede on this point that you are right. If I google “is intelligence a physical trait” the results I get say: no. In my defense, I thought I was careful to qualify that what I was talking about earlier as the biological component of intelligence, but I’m okay admitting I’ve made some mistakes here.
It is worth noting that “Intelligence is one of the most heritable behavioural traits” and that “studies have consistently shown that genetic influence on individual differences in intelligence is substantial”. https://www.nature.com/articles/mp2014105
> A person with IQ 180 is likely two orders of magnitude more intelligent in absolute terms than someone with IQ 100.
There is zero scientific basis for that claim. This is exactly what I was talking about from the top. This popular interpretation of extremely high IQ scores substantially overstates what can legitimately be inferred from the numerical scores. That’s why I call it a misconception. IQ only directly measures how unusual someone’s intelligence is, not how good it is. IQ is at best only moderately good at predicting cognitive performance on some tasks, and whether it predicts anything is highly dependent on the type of task. And after reading about it more, I’m going to correct myself and agree that IQ does not predict cognitive brain capacity, and we don’t yet have anything that does. But scientists are looking for that.
Anyway, this belief you have that 180 IQ vs 100 IQ is 100x more intelligent - whatever more intelligent actually means - is extremely extreme!! Why do you believe this, and what evidence is there of your claim? You’re absolutely right that I disagree with you there. But I will read and consider any supporting links or data you can provide, and I am open to changing my mind if the data is compelling. There’s a reason that IQ is considered outdated now, that scientists do not accept that intelligence is 1-dimensional, and that cognitive scientists now talk about multiple intelligences, and use g instead. https://en.wikipedia.org/wiki/G_factor_(psychometrics)
> As far as I know, neither brain size nor the number of neurons nor synapses is correlated with IQ.
Human brain size does correlate with IQ somewhat. Now you know.
Admittedly I skimmed most of your comment. I'm not masochistic enough to enjoy reading what an idiot I am or whatever else you wrote there, and I come to this site for enjoyment. Let me know if I missed something important, like not understanding what you're saying at all yet again.
I agree that intelligence is highly genetic. So is schizophrenia, though, and I don't think anyone would describe schizophrenia as a physical trait. So merely being genetic is not a proof of being a physical attribute.
Just like intelligence and IQ are two separate things, so is intelligence and the underlying biological structures enabling intelligence. Saying the former when you mean the latter is not just unclear, it's flat out incorrect.
There is as much proof of the 100 times intelligence gap as there's for any other number. Which, yes, is zero. Nobody has come up yet with any method to quantify intelligence directly, and until that happens, it'll be impossible to make any objective statement about raw amount of anybody's intelligence. I was just saying what I personally believe to be most likely.
I was wrong about lack of correlation. Thank you for the links. That said, I did dig further, and from what I gathered, brain size differences account for at most 25% of variation in IQ. The other 75% must be either non-physical differences, or physical differences that don't affect brain size. My bet is on the former, because there's neither any evidence nor a theoreticsl model for the latter. Granted, I haven't looked for a theoretical model too deeply; you're more than welcome to prove me wrong yet again.
The biggest obstacle for the ... whatever the thing you're saying is called, I'm 100% sure I'd get it wrong if I tried to name it, so I won't... are child geniuses. Children have smaller bodies, shorter legs, and less muscle mass than adults. There are extremely few 7 year old boys who are taller, faster or stronger than a median 25 year old man - around one in a billion for height, probably zero for the other two. Similar story with head circumference, though to a lesser degree. The 95% range for 7 year olds barely overlaps with the range for adults. Every single case I could find of a child that young reaching the mean HC of an adult man (57cm) was a sad story of a rare medical condition that definitely didn't make them smarter. I use it to conclude it's extremely rare for child heads - and by proxy, child brains - to reach the size of adults. If intelligence was physical, that should also prevent virtually all children from being more intelligence than a median adult. And yet, there's plenty of children whose intelligence surpasses most adults. It's almost commonplace. How do you reconcile that with your argument?
So why do you believe someone with 180 IQ is that much smarter than 100, if you agree there are no metrics to back it up? Surely there would be something that correlates with a two orders of magnitude increase in intelligence. Doesn’t the lack of such data suggest it’s actually not likely?
Human head size reaches 80% by age two. IQ tests for 7 years olds are completely different tests and even different scales than IQ tests for adults. (See WPPSI vs WISC vs WAIS) The IQ scoring formula originally divided ‘mental age’ by chronological age to adjust (this is the Q in IQ), because it’s well known that a 10 year old knows more things and has a better memory than a 7 year old.
Child geniuses are a much bigger problem for your argument than mine. If IQ measured the innate biological component of intelligence, then it’d be no surprise at all that you can find young outliers. But if intelligence is trained, then child geniuses would be meaningless. If intelligence is entirely trained, that means it’s entirely acquired during life, and so then everyone can become a “genius” with effort, and IQ would only be measuring motivation and not intelligence.
> So why do you believe someone with 180 IQ is that much smarter than 100, if you agree there are no metrics to back it up?
Because that's how it works for most other learnable, trainable skills that aren't dependent on physical limits of the body, and I don't see why intelligence would be any different. Yes I'm still saying intelligence isn't physical.
I know IQ is (used to be?) age-adjusted. I wasn't talking about IQ there, I'm talling about raw intelligence. Child prodigies beat adults at chess, at maths, at programming, you name it - and it's happening way more commonly than head/brain size variation would allow for it.
I never said entirely trained. For somebody who just spent 10 whole paragrahs across 3 comments (+/- 50%, like I said I wasn't really reading) chastising me for not reading carefully, you sure fumbled this one.
Think of intelligence like playing piano. Most people can't play piano. But most people can learn to play piano, to some extent. How good they are depends mostly on how much they've been learning, but everyone has some point they just can't push past through no matter how much they try. Usually that point is pretty low, way before the general audience is willing to pay for watching. For a tiny minority, that ceiling is much higher and the growth they get from practice is much faster too - we call these people talented or naturally gifted.
And then there are the piano prodigies who absolutely shred the keyboard at the age of 5. There are enough of them that you can't explain it away with abnormal growth of any relevant body organ. That's what I mean when I say head circumference variation is too small in children to explain the number of child geniuses, if intelligence is entirely biological.
IQ measures whatever intelligence happens to be. It's just an assumption that the kind of intelligence that helps with IQ tests is entirely biological, and only under that assumption IQ measures the biological component only. But that assumption is likely wrong, considering you can train to score better at IQ tests (it's a fact). Either intelligence isn't biological, or IQ metric sucks at isolating the biological component - feel free to assume the latter.
Oh you misunderstood me; I wasn't making any claims about what you said, I was only pointing out the logical conclusion that measuring acquired skills is not measuring intelligence, it would only be measuring effort & interest. I'm trying to point out why the training part of IQ or intelligence is the far less interesting part. The more trainable it is, the more nobody cares. What many people want to know is what's the capacity for intelligence; what's the ceiling on training. Think about it: the single most valid and important use case for intelligence testing is deciding how to adapt the educational curriculum for children.
BTW I'm not the one repeatedly bringing up the 20% thing, I'm trying to drop it.
You are arguing that intelligence is primarily trained and not primarily a physical trait, no? You did make a claim about a two orders of magnitude intelligence difference between IQs of 180 and 100, right? You seem to agree that "intelligence" is a combination of genetics and training, is that correct? And you believe the variance in IQ scores is mostly due to training and not genetics, or what?
This is somewhat going in circles now. I've agreed multiple times that IQ scores are somewhat trainable, and you're ignoring the facts that 1) it's only a little bit trainable not a lot, and 2) that people generally tend to have a stable IQ measurement over their lifetime (adults moreso than kids), and 3) that the goal of IQ tests is to try to factor out training to some degree, which is why it used to divide by age and now measures only rank. Cultural bias was a huge a valid criticism of earlier IQ tests, and they've taken steps to avoid relying on knowledge.
I'd certainly love to hear a more interesting argument or any evidence at all for you two orders of magnitude claim, but I can accept you're telling me your opinion and not something defensible. What we have agreed on is that IQ doesn't measure intelligence, it measures rank. One way or another, that fact could fully explain the outcome of the article we're commenting on.
> Child prodigies beat adults at chess, at maths, at programming, you name it.
FWIW, that's not really true in any meaningful way, and to some degree it contradicts what you're saying about training intelligence. The child outliers are not beating the adult outliers. Some children can outperform the average adult, but what has that got to do with anything? Some adults can also outperform the average adult. If children are outperforming adults, and they've had less training time, then how do you explain the superior performance? What is a naturally gifted child prodigy, if not evidence of physical traits?
> You are arguing that intelligence is primarily trained and not primarily a physical trait, no?
No I'm not. Not as stated.
You are correct in that the more trainable intelligence is, the less people care about IQ. Coincidentally, people's caring about IQ has been falling drastically the last couple decades.
> What is a naturally gifted child prodigy, if not evidence of physical traits?
It's evidence that it's not a physical trait at all. At least not the kind that scales with size (and therefore would have a relatively narrow variance among adults with both the median and the modal value in the dead center between 3rd and 97th percentile, while undergoing a massive change around the time of puberty, so much so that reaching average post-puberty score before puberty is near impossible).
Obviously everything ultimately comes down to neural connections powering the brain. Knitting, bull riding and playing piano are just as much physical attributes as intelligence. We live in a physical world after all. But that makes the term "physical trait" quite useless. So instead, I'm choosing to interpret physical trait as anything that is almost entirely determined by measurable aspects of a person's physical body. And intelligence just isn't it.
Did you mean to say "intelligence is primarily genetic" instead? That I would agree with.
> Did you mean to say “intelligence is primarily genetic” instead? That I would agree with.
Perhaps I did mean to say child prodigies are evidence of the heritability of intelligence; that it suggests intelligence has a large, possibly majority, genetic component, if kids are outliers without much training.
Okay, so you’ve been objecting to ‘physical traits’ but agree with ‘genetic’… What is the difference in your mind between those? I see them as, broadly speaking, the same thing. Physical traits are phenotypes, no? Genetics is the biological component I’ve been talking about all along, and heritability is defined as that which is genetic, i.e., not explained by the environment or chance, i.e., not due to training.
Knitting, bull riding, and playing piano are neither intelligence, nor are they physical attributes. They are learned skills. It seems some people may have genes that may help them learn these skills faster than other people, but these are not ‘physical traits’ in any way shape or form, and your commentary on that term isn’t making sense to me right now. If you think piano playing is a ‘physical trait’, that could explain much of the miscommunication in this thread.
I must have misunderstood you above, we completely agree there; piano playing is not a physical trait.
We are finally getting somewhere, it’s too bad this got too deep before finding a basis for productive conversation. The paper you linked is very interesting, I would just note that your strong claim with the qualifier “largely” in your statement is not supported by the paper. The paper does not demonstrate musical skills are primarily or ‘largely’ genetic, it only suggests there may be some heritability of music perception. At least some of genes it mentions are nothing more than hearing anatomy, so of course they affect music, but they also affect basic speed and any audio. It’d be wise to not overstate what that paper is saying.
I could link to a bunch more studies that find more direct genetic links to musical aptitude in particular rather than musical perception in general. But I'd rather skip the busy work and jump straight to the point where we both agree to the following.
1. Musical talent is hereditary to a significant degree.
2. Musical talent is NOT a physical trait.
3. Therefore, being hereditary is not a proof of being a physical trait, despite the literal physical differences in DNA sequence.
#1 is not a justifiable statement as written, #2 is true, #3 needs better terminology. Genetics does determine physical traits (physical traits are defined as phenotypes), heredity is about genetic variation. If you agree musical ability or intelligence are significantly genetic, then it follows that musical ability or intelligence must be attached to, associated with, or correlated with physical traits of some kind.
In light of your acceptance of intelligence having a significant genetic component, I wanted to re-evaluate the discussion from the top. You pushed back on my attempts to discuss genetics and made strong claims about training being important for intelligence, and now you’re making strong claims about genetics being important. I don’t know where that leaves us. My original point, recall, was that genetic variation doesn’t support the popular high-IQ narrative of so called super geniuses. Genetics cannot explain your claim of 100x difference in intelligence, and the only thing we’ve talked about that does explain it is training, which is not genetic, and, we both agree, boring.
There is a world of difference between "is a physical trait" and "is attached to, associated with, or correlated with physical traits". The way I see it, saying that intelligence is correlated with physical body features is admitting that intelligence is not a physical trait itself after all.
The first reason I insist on the difference is because absolutely everything indirectly depends on physicality of the biological body. Spirituality aside, there isn't a single thing about humans that doesn't depend on the shape or size or chemistry or electrical charge of something somewhere. This makes "physical trait" an utterly useless category, one that clearly includes playing piano, and I really don't like that.
The second reason I insist on the difference is because the correlation doesn't have to be linear. There's no reaso why it can't be quadratic or logarithmic or exponential or hyperbolic or whatever. Being a literal physical feature imposes normal distribution with tight variance. Merely being correlated does not. If you still want to argue geniuses are not that much more intelligent than average people, you'd need more evidence than simple hereditability.
When you say "intelligence is a physical trait", I hear "there is a part of parts of the brain that have a certain total volume/mass/density/number of neurons/synapses/neural pathways/etc., and that number is the literal definition of intelligence". It's how it works for every other thing that we call a physical trait. If you didn't mean it like that, maybe you should have used a different terminology from the get go.
Now excuse me while I go looking for 10-15 more citations on the genetic component of musical ability that you're definitely not going to dismiss as irrelevant for one reason or another.
It seems like you maybe missed the part in the middle of the thread where I said you’re right about IQ scores and what we call intelligence not being a so called physical trait. I’m not arguing that at this point and haven’t been for a while, because it became clear we are talking about different things. I’m looking for more mature terminology at this point, established phrases and concepts we can agree on, because this is too sloppy of a discussion. You’re making assumptions and jumping to a weird conclusion about what ‘physical traits’ means and I don’t agree that it’s useless, other than that the term has somewhat poisoned this discussion and is preventing progress. Physical traits are phenotypes, and phenotypes are an extremely useful notion in a discussion of genetics vs environment vs chance.
Your statement about correlation being an admission of not being a physical trait sounds naive to me; it’s ignoring the existence of polygenic traits.
Another source of terminology confusion here is the difference in what we mean by ‘intelligence’, and it’s probably way more important than what ‘physical attribute’ means. I really meant something different by ‘intelligence’ than you mean, and that’s my fault for not clarifying I was trying to focus on heritability and factor out learned skill.
I would love to see additional references about music and heredity, I’m looking forward to it.
Great question. My primary point was that the IQ scale and absolute intelligence aren’t the same things, and people often assume they are (this article’s premise, for example), or even worse many people assume that absolute intelligence goes up exponentially along with the rarity of the IQ ranking. Height was simply an example of how there’s an obvious discrepancy between standard deviations and the underlying absolute metric; the rarity of one person’s height says literally nothing about how tall they are, and yet people assume without any justification whatsoever that the rarity of someone’s IQ score does say something about how smart they are. All human physical characteristics have a relatively narrow range, and they don’t increase exponentially. Running is another example - Usain Bolt can run faster than 99.9999% of people, and yet he’s only 10% faster than the average competitive sprinter and maybe ~50% faster than the average person not trained in running. You’ll see similar distributions with weight lifting. The number of brain cells doesn’t grow without bound - we all have similar amounts. The construction of the brain cells and the structure of the brain isn’t wildly different from person to person. Most skulls are approximately the same size. Most eyeballs and ears and arms and legs all vary by about the same amount height and head size varies. So, there really is good reason to start with the hypothesis that raw biological cognitive capacity and speed don’t vary by a lot more than height does, and - importantly - that they all top out at the upper end of the distribution.
> Did you mean to imply the ratio between intelligence of someone with IQ of 100 and IQ 180 is smaller than a factor of 1.8, or did you mean something else?
I meant that from the start, assuming the factor is 1.8 is a very bad assumption. That’s simply not how standard deviations work. Yes, please consider the possibility that the cognitive capacity of IQ 180 is less than 1.8 times more than that of IQ 100. If intelligence has a similar distribution to other physical characteristics, then difference between the mean and the first standard deviations is much larger than the difference between the first and second standard deviations. Translation: the jump from 130 to 160 is probably much smaller than the jump from 100 to 130. And going from 160 to 190 IQ, there is likely a negligible, unmeasurable difference in absolute intelligence. This is the opposite of the popular conceptions of IQ, right?
> The evidence that intelligence can be trained is that every metric of intelligence ever invented is consistently going up
Again, you are confusing raw intelligence with psychometric tests. Yes you can train for an IQ test. No, you cannot train intelligence. ‘Intelligence’ in this context, the kind we are discussing, is defined as the biological component of cognitive capacity that cannot be trained. Intelligence and skill are two different things, go ahead and google that question. The fact that IQ tests are not currently able to differentiate between intelligence and skill is a well known shortcoming of IQ tests, and that relates directly to my initial point: IQ is not a great measure and assuming that IQ score and happiness would have a correlation anywhere near 1 is a very bad assumption.
> Sure, you can always claim that all of those are skills separate from intelligence
Yes, yes I can, since it’s true. Therefore, given that fact, the question you asked is one for you to ponder and answer. What is the source of the claim that being better at one “automatically makes you better at all the others”? Does taking IQ tests give you more brain cells or increase your cognitive speed? You’re hand-waving this training argument and ignoring the fact that people who train for IQ tests still top out and hit a wall regardless of the amount of practice, they don’t increase their scores indefinitely. If intelligence could be trained, why isn’t everyone a so-called high IQ genius?
> Why didn’t you correct me back then?
Hehe I don’t need to argue every wrong thing you say, and doing so doesn’t make for good conversation. Your assumptions only reflect on you, not me. I assumed you’d eventually re-read the comment you replied to and figure out that using 20% in your argument was straw man given that I actually gave an example of a 50% variance in height in that same comment, and that I only used height as an analogy, not a claim about intelligence. When people seem to misunderstand my comments, whether it’s a mistake or intentional, I prefer to try to clarify my broader intent and not nitpick every word. Rebutting every single thing tends to escalate arguments and send the impression that you’re reflexively arguing rather than thinking, and seeking disagreement rather than agreement. I try to follow the HN guidelines, and I’m by no means always perfect, but they are pretty good guidelines, right?