To be fair here, part of the problem is more so that innate intelligence does exist, but is on a normal distribution, not a power law distribution, so you can’t have massive differences in innate intelligence being the dominant factor for success.
IQ is on a normal distribution because we force it to be normalized that way. Task performance tends to vary by large factors, resembling something closer to a log normal or exponential distribution, suggesting intelligence is indeed heavy tailed.
It sure has come up frequently enough that I’ve been thinking about writing this post. I hope I’ll get around to it, but would also greatly appreciate anyone else familiar with the literature here to write something.
A crux here is that I think there are reasons beyond defining it to be normal that the normal distribution prevails, and the biggest reason for this is that I generally model the contributions of human intelligence as additive, not an AND function and in particular that they are independent, that is one gene for intelligence can do it’s work without requiring any other genes. This basically lets us construct the normal distribution, and explains why it’s useful to model it as a normal distribution.
As far as the result that task performance is heavy tailed, another consistent story is that what’s going on is people get mostly lucky, and then post-hoc a story about how their innate intelligence/sheer willpower made them successful, and this is important, since I suspect it’s the most accurate story given the divergence of us being normal, but the world is extreme.
A lot of genes have multiplicative effects instead of additive effects. E.g. vegetable size is surprisingly log-normally distributed, not normally distributed, so I don’t think you should have a huge prior on normal here. See also one of my favorite papers of all time “Log-Normal Distributions Across The Sciences”.
To be fair here, part of the problem is more so that innate intelligence does exist, but is on a normal distribution, not a power law distribution, so you can’t have massive differences in innate intelligence being the dominant factor for success.
IQ is on a normal distribution because we force it to be normalized that way. Task performance tends to vary by large factors, resembling something closer to a log normal or exponential distribution, suggesting intelligence is indeed heavy tailed.
I’d love to see a top level post laying this out, it seems like it’s been a crux in a few recent discussions.
It sure has come up frequently enough that I’ve been thinking about writing this post. I hope I’ll get around to it, but would also greatly appreciate anyone else familiar with the literature here to write something.
A crux here is that I think there are reasons beyond defining it to be normal that the normal distribution prevails, and the biggest reason for this is that I generally model the contributions of human intelligence as additive, not an AND function and in particular that they are independent, that is one gene for intelligence can do it’s work without requiring any other genes. This basically lets us construct the normal distribution, and explains why it’s useful to model it as a normal distribution.
As far as the result that task performance is heavy tailed, another consistent story is that what’s going on is people get mostly lucky, and then post-hoc a story about how their innate intelligence/sheer willpower made them successful, and this is important, since I suspect it’s the most accurate story given the divergence of us being normal, but the world is extreme.
A lot of genes have multiplicative effects instead of additive effects. E.g. vegetable size is surprisingly log-normally distributed, not normally distributed, so I don’t think you should have a huge prior on normal here. See also one of my favorite papers of all time “Log-Normal Distributions Across The Sciences”.