But 32% is low enough that we’re pretty vulnerable to selection bias
The large majority of LessWrongers in the USA have however also provided their SAT scores, and those are also very high values (from what little I know of SATs)...
The large majority of LessWrongers in the USA have however also provided their SAT scores, and those are also very high values (from what little I know of SATs)...
The reported SAT numbers are very high, but the reported IQ scores are extremely high. The mean reported SAT score, if received on the modern 1600 test, corresponds to an IQ in the upper 120s, not the upper 130s. The mean reported SAT2400 score was 2207, which corresponds to 99th but not 99.5th percentile. 99th percentile is an IQ of 135, which suggests that the self-reports may not be that off compared to the SAT self-reports.
Some of us took the SAT before 1995, so it’s hard to disentangle those scores. A pre-1995 1474 would be at 99.9x percentile, in line with an IQ score around 150-155. If you really want to compare, you should probably assume anyone age 38 or older took the old test and use the recentering adjustment for them.
I’m also not sure how well the SAT distinguishes at the high end. It’s apparently good enough for some high IQ societies, who are willing to use the tests for certification. I was shown my results and I had about 25 points off perfect per question marked wrong. So the distinction between 1475 and 1600 on my test would probably be about 5 total questions. I don’t remember any questions that required reasoning I considered difficult at the time. The difference between my score and one 100 points above or below might say as much about diligence or proofreading as intelligence.
Admittedly, the variance due to non-g factors should mostly cancel in a population the size of this survey, and is likely to be a feature of almost any IQ test.
That said, the 1995 score adjustment would have to be taken into account before using it as a proxy for IQ.
Conversion is a very tricky matter, because the correlation is much less than 1 ( 0.369 in the survey, apparently).
With correlation less than 1, regression towards the mean comes into play, so the predicted IQ from perfect SAT is actually not that high (someone posted coefficients in a parallel discussion), and predicted SAT from very high IQ is likewise not that awesome.
The reason the figures seem rather strange, is that they imply some kind of extreme filtering by IQ here. The negative correlation between time here and IQ suggest that the content is not acting as much of a filter, or is acting as a filter in the opposite direction.
The negative correlation between time here and IQ suggest that the content is not acting as much of a filter, or is acting as a filter in the opposite direction.
Well, alternatively old-timers feel it’s more important to accurately estimate their IQ, and new-comers feel it’s more important to be impressive. There also might not be an effect that needs explaining: I haven’t looked at a scatterplot of IQ by time in community or karma yet for this year; last year, there were a handful of low-karma people who reported massive IQs, and once you removed those outliers the correlation mostly vanished.
You still need to explain how the population ended up so extremely filtered.
Without the rest of the survey, one might imagine that various unusual beliefs here are something that’s only very smart people can see as correct and so only very smart people agree and join, but the survey has shown that said unusual beliefs weren’t correlated with self reported IQ or SAT score.
The Wikipedia article states that those are percentiles of test-takers, not the population as a whole. What percentage of seniors take the SAT? I tried googling, but I could not find the figure.
My first thought is that most people who don’t take the SAT don’t intend to go to college and are likely to be below the mean reported SAT score, but then I realized that a non-negligible subset of those people must have taken only the ACT as their admission exam.
I don’t have solid numbers myself, but percentile of test-takers should underestimate percentile of population. However, there is regression to the mean to take into account, as well as that many people take the SAT multiple times and report the most favorable score, both of which suggest that score on test should overestimate IQ, and I’m fudging it by treating those two as if they cancel out.
Possibly. My suspicion is that less people have taken multiple professional IQ tests (I’ve only taken one professional one) than multiple SATs (I think I took it three times, at various ages). I score significantly better on the Raven’s subtest than on other subtests, and so my IQ.dk score was significantly higher than my professional IQ test last year- but this year I only reported the professional one, because that was all that was asked for. (I might not be representative.)
The large majority of LessWrongers in the USA have however also provided their SAT scores, and those are also very high values (from what little I know of SATs)...
The reported SAT numbers are very high, but the reported IQ scores are extremely high. The mean reported SAT score, if received on the modern 1600 test, corresponds to an IQ in the upper 120s, not the upper 130s. The mean reported SAT2400 score was 2207, which corresponds to 99th but not 99.5th percentile. 99th percentile is an IQ of 135, which suggests that the self-reports may not be that off compared to the SAT self-reports.
Some of us took the SAT before 1995, so it’s hard to disentangle those scores. A pre-1995 1474 would be at 99.9x percentile, in line with an IQ score around 150-155. If you really want to compare, you should probably assume anyone age 38 or older took the old test and use the recentering adjustment for them.
I’m also not sure how well the SAT distinguishes at the high end. It’s apparently good enough for some high IQ societies, who are willing to use the tests for certification. I was shown my results and I had about 25 points off perfect per question marked wrong. So the distinction between 1475 and 1600 on my test would probably be about 5 total questions. I don’t remember any questions that required reasoning I considered difficult at the time. The difference between my score and one 100 points above or below might say as much about diligence or proofreading as intelligence.
Admittedly, the variance due to non-g factors should mostly cancel in a population the size of this survey, and is likely to be a feature of almost any IQ test.
That said, the 1995 score adjustment would have to be taken into account before using it as a proxy for IQ.
Conversion is a very tricky matter, because the correlation is much less than 1 ( 0.369 in the survey, apparently).
With correlation less than 1, regression towards the mean comes into play, so the predicted IQ from perfect SAT is actually not that high (someone posted coefficients in a parallel discussion), and predicted SAT from very high IQ is likewise not that awesome.
The reason the figures seem rather strange, is that they imply some kind of extreme filtering by IQ here. The negative correlation between time here and IQ suggest that the content is not acting as much of a filter, or is acting as a filter in the opposite direction.
Well, alternatively old-timers feel it’s more important to accurately estimate their IQ, and new-comers feel it’s more important to be impressive. There also might not be an effect that needs explaining: I haven’t looked at a scatterplot of IQ by time in community or karma yet for this year; last year, there were a handful of low-karma people who reported massive IQs, and once you removed those outliers the correlation mostly vanished.
You still need to explain how the population ended up so extremely filtered.
Without the rest of the survey, one might imagine that various unusual beliefs here are something that’s only very smart people can see as correct and so only very smart people agree and join, but the survey has shown that said unusual beliefs weren’t correlated with self reported IQ or SAT score.
The Wikipedia article states that those are percentiles of test-takers, not the population as a whole. What percentage of seniors take the SAT? I tried googling, but I could not find the figure.
My first thought is that most people who don’t take the SAT don’t intend to go to college and are likely to be below the mean reported SAT score, but then I realized that a non-negligible subset of those people must have taken only the ACT as their admission exam.
I don’t have solid numbers myself, but percentile of test-takers should underestimate percentile of population. However, there is regression to the mean to take into account, as well as that many people take the SAT multiple times and report the most favorable score, both of which suggest that score on test should overestimate IQ, and I’m fudging it by treating those two as if they cancel out.
Don’t most people who report IQ scores do the same thing if they have taken multiple tests?
Possibly. My suspicion is that less people have taken multiple professional IQ tests (I’ve only taken one professional one) than multiple SATs (I think I took it three times, at various ages). I score significantly better on the Raven’s subtest than on other subtests, and so my IQ.dk score was significantly higher than my professional IQ test last year- but this year I only reported the professional one, because that was all that was asked for. (I might not be representative.)
Not if they followed the survey instructions, which asked for only the scores from the most recent professional IQ test they took.