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?