Most Less Wrong readers’ performance on Raven’s Matrices would be between 2 SD and 3 SD above the mean
We asked people to take a Raven’s Matrices IQ test on previous surveys, like the 2012 survey. According to one of my old comments, LWers with positive karma averaged 127 on the test, somewhat below 2 SDs above the mean. I suspect that’s inflated by nonresponse.
There were questions about whether or not the Raven’s was a good IQ test to be using, as many people thought the version hosted on iqtest.dk underestimated their IQ, and it was not included on later surveys.
I’m pretty sure that the the issue is with the conversion between performance on the iqtest.dk test and score. My best guess is that they’re determining percentiles relative to other test takers, and that people who spend time taking IQ tests online are unrepresentatively high IQ.
My best guess is that they’re determining percentiles relative to other test takers, and that people who spend time taking IQ tests online are unrepresentatively high IQ.
I think this is likely; I seem to recall iqtest.dk saying something to that effect. Given the various reporting biases involved, though, I’m unwilling to jump immediately to that as a conclusion. I recall the Raven’s numbers being lower than what you would expect given the SAT numbers, but being closer to the SAT numbers than the self-reported IQ numbers, which were higher than you would expect from the SAT numbers.
That is, even if I agree with your prior that LWers do better on Raven’s than on other tests, observing LWers doing worse on a Raven’s test than other tests should reduce my confidence in that, rather than me just using the prior to adjust the evidence to agree with it. (Administering a properly normed test, of course, would screen off the improperly normed test.)
We asked people to take a Raven’s Matrices IQ test on previous surveys, like the 2012 survey. According to one of my old comments, LWers with positive karma averaged 127 on the test, somewhat below 2 SDs above the mean. I suspect that’s inflated by nonresponse.
There were questions about whether or not the Raven’s was a good IQ test to be using, as many people thought the version hosted on iqtest.dk underestimated their IQ, and it was not included on later surveys.
I’m pretty sure that the the issue is with the conversion between performance on the iqtest.dk test and score. My best guess is that they’re determining percentiles relative to other test takers, and that people who spend time taking IQ tests online are unrepresentatively high IQ.
I think this is likely; I seem to recall iqtest.dk saying something to that effect. Given the various reporting biases involved, though, I’m unwilling to jump immediately to that as a conclusion. I recall the Raven’s numbers being lower than what you would expect given the SAT numbers, but being closer to the SAT numbers than the self-reported IQ numbers, which were higher than you would expect from the SAT numbers.
That is, even if I agree with your prior that LWers do better on Raven’s than on other tests, observing LWers doing worse on a Raven’s test than other tests should reduce my confidence in that, rather than me just using the prior to adjust the evidence to agree with it. (Administering a properly normed test, of course, would screen off the improperly normed test.)