Intelligence being on a normal distribution is entirely unconnected to the magnitude of cognitive differences between humans—the units of the standard deviation are IQ points (1 SD = 15 IQ points), but IQ points aren’t a linear measure of intelligence as applied to optimization power/learning ability/etc. - for that reason, it’s meaningless to consider how large a percentage of people fits into how many SDs.
That doesn’t follow. They have thin tails (in some well-specified mathematical sense), but that’s unconnected to them generating or not generating orders of magnitude differences.
Uh, I was under the impression that IQ was somewhat fat tailed.
[Epistemic status: pretty low confidence. That’s just a meme I’ve absorbed and not something I’ve independently verified. I wouldn’t be surprised to learn that I’m mistaken in an important aspect here.
Intelligence being on a normal distribution is entirely unconnected to the magnitude of cognitive differences between humans—the units of the standard deviation are IQ points (1 SD = 15 IQ points), but IQ points aren’t a linear measure of intelligence as applied to optimization power/learning ability/etc. - for that reason, it’s meaningless to consider how large a percentage of people fits into how many SDs.
Still, it’s very hard to generate orders of magnitude differences, because normal distributions have very thin tails.
That doesn’t follow. They have thin tails (in some well-specified mathematical sense), but that’s unconnected to them generating or not generating orders of magnitude differences.
Uh, I was under the impression that IQ was somewhat fat tailed.
[Epistemic status: pretty low confidence. That’s just a meme I’ve absorbed and not something I’ve independently verified. I wouldn’t be surprised to learn that I’m mistaken in an important aspect here.
Self reported IQ is pretty fat tailed.
Aren’t there selection effects there? People who received higher IQ test scores are more likely to report their IQ score?
Indeed.