I’ve heard repeatedly that the correlation between IQ and achievement after about 120 (z = 1.33) is pretty weak, possibly even with diminishing returns up at the very top. Is moving to 250 (z = 10) passing a sort of threshold of intelligence at some point where this trend reverses? Or is the idea that IQ stops strongly predicting achievement above 120 wrong?
This is something I’ve been curious about for a while, so I would really appreciate your help clearing the issue up a bit.
In agreement with Vaniver’s comment, there is evidence that differences in IQ well above 120 are predictive of success, especially in science. For example:
IQs of a sample of eminent scientists were much higher than the average for science PhDs (~160 vs ~130)
Among those who take the SAT at age 13, scorers in the top .1% end up outperforming the top 1% in terms of patents and scientific publications produced as adults
I don’t think I have good information on whether these returns are diminishing, but we can at least say that they are not vanishing. There doesn’t seem to be any point beyond which the correlation disappears.
I just read the “IQ’s of eminent scientists” and realized I really need to get my IQ tested.
I’ve been relying on my younger brother’s test (with the knowledge that older brothers tend to do slightly better but usually within an sd) to guesstimate my own IQ but a) it was probably a capped score like Feynman’s since he took it in middle school and b) I have to know if there’s a 95% chance of failure going into my field. I’d like to think I’m smart enough to be prominent, but it’s irrational not to check first.
Thanks for the information; you might have just saved me a lot of trouble down the line, one way or the other.
I just read the “IQ’s of eminent scientists” and realized I really need to get my IQ tested.
I’d be very careful generalizing from that study to the practice of science today. Science in the 1950s was VERY different, the length of time to the phd was shorter, postdocs were very rare, and almost everyone stepped into a research faculty position almost immediately.
In today’s world, staying in science is much harder- there are lots of grad students competing for many postdocs competing for few permanent science positions. In today’s world, things like conscientiousness, organization skills,etc (grant writing is now a huge part of the job) play a much larger role in eventually landing a job in the past, and luck is a much bigger driver (whether a given avenue of exploration pays off requires a lot of luck. Selecting people whose experiments ALWAYS work is just grabbing people who have been both good AND lucky). It would surprise me if the worsening science career hasn’t changed the make up of an ‘eminent scientist’.
At the same time, all of those points except the luck one could be presented as evidence that the IQ required to be eminent has increased rather than the converse. Grant writing and schmoozing are at least partially a function of verbal IQ, IQ in general strongly predicts academic success in grad school, and competition tends to winnow out the poor performers a lot more than the strong.
Not that I really disagree, I just don’t see it as particularly persuasive.
whether a given avenue of exploration pays off requires a lot of luck. Selecting people whose experiments ALWAYS work is just grabbing people who have been both good AND lucky
That’s just one of the unavoidable frustrations of human nature though; an experiment which dis-confirms it’s hypothesis worked perfectly, it just isn’t human nature to notice negatives.
At the same time, all of those points except the luck one could be presented as evidence that the IQ required to be eminent has increased rather than the converse.
I disagree for several reasons. Mostly, conscientiousness, conformity,etc are personality traits that aren’t strongly correlated with IQ (conscientiousness may even be slightly negatively correlated).
IQ in general strongly predicts academic success in grad school, and competition tends to winnow out the poor performers a lot more than the strong.
Would it surprise you to know that the most highly regarded grad students in my physics program all left physics? They had a great deal of success before and in grad school (I went to a top 5 program) , but left because they didn’t want to deal with the administrative/grant stuff, and because they didn’t want to spend years at low pay.
I’d argue that successful career in science is selecting for some threshhold IQ and then much more strongly for a personality type.
Mensa apparently doesn’t consider the SAT to have a high-enough g loading to be useful as an intelligence test after 1994. Although the website’s figure are certainly encouraging, it’s probably best to take them with a bit of salt.
True, but note that, in contrast with Mensa, the Triple Nine Society continued to accept scores on tests taken up through 2005, though with a higher cutoff (of 1520) than on pre-1995 tests (1450).
Also, SAT scores in 2004 were found to have a correlation of about .8 with a battery of IQ tests, which I believe is on par with the correlations IQ tests have with each other. So the SAT really does seem to be an IQ test (and an extremely well-normed one at that if you consider their sample size, though perhaps not as highly g-loaded as the best, like Raven’s).
But yeah, if you want to have high confidence in a score, probably taking additional tests would be the best bet. Here’s a list of high-ceiling tests, though I don’t know if any of them are particularly well-normed or validated.
I’ve heard repeatedly that the correlation between IQ and achievement after about 120 (z = 1.33) is pretty weak, possibly even with diminishing returns up at the very top.
Is this what you intended to say? “Diminishing returns” seems to apply at the bottom the scale you mention. You’ve already selected the part where returns have started diminishing. Sometimes it is claimed that that at the extreme top the returns are negative. Is that what you mean?
Yeah, that’s just me trying to do everything in one draft. Editing really is the better part of clear writing.
I meant something along the lines of “I’ve heard it has diminishing returns and potentially [, probably due to how it affects metabolic needs and rate of maturation] even negative returns at the high end.”
Or is the idea that IQ stops strongly predicting achievement above 120 wrong?
Most IQ tests are not very well calibrated above 120ish, because the number of people in the reference sample that scored much higher is rather low. It’s also the case that achievement is a function of several different factors, which will probably become the limiting factor for most people at IQs higher than 120. That said, it does seem that in physics, first-tier physicists score better on cognitive tests than second-tier physicists, which suggests that additional IQ is still useful for achievement in the most cognitively demanding fields. It seems likely that augmented humans who do several times better than current humans on cognitive tests will also be able to achieve several times as much in cognitively demanding fields.
Is moving to 250 (z = 10) passing a sort of threshold of intelligence
First, IQ tests don’t go to 250 :-) Generally speaking standard IQ tests have poor resolution in the tails—they cannot reliably identify whether you have the IQ of, say, 170 or 190. At some point all you can say is something along the lines of “this person is in the top 0.1% of people we have tested” and leave it at that.
Second, “achievement” is a very fuzzy word. People mean very different things by it. And other than by money it’s hard to measure.
I’ve heard repeatedly that the correlation between IQ and achievement after about 120 (z = 1.33) is pretty weak, possibly even with diminishing returns up at the very top. Is moving to 250 (z = 10) passing a sort of threshold of intelligence at some point where this trend reverses? Or is the idea that IQ stops strongly predicting achievement above 120 wrong?
This is something I’ve been curious about for a while, so I would really appreciate your help clearing the issue up a bit.
In agreement with Vaniver’s comment, there is evidence that differences in IQ well above 120 are predictive of success, especially in science. For example:
IQs of a sample of eminent scientists were much higher than the average for science PhDs (~160 vs ~130)
Among those who take the SAT at age 13, scorers in the top .1% end up outperforming the top 1% in terms of patents and scientific publications produced as adults
I don’t think I have good information on whether these returns are diminishing, but we can at least say that they are not vanishing. There doesn’t seem to be any point beyond which the correlation disappears.
I just read the “IQ’s of eminent scientists” and realized I really need to get my IQ tested.
I’ve been relying on my younger brother’s test (with the knowledge that older brothers tend to do slightly better but usually within an sd) to guesstimate my own IQ but a) it was probably a capped score like Feynman’s since he took it in middle school and b) I have to know if there’s a 95% chance of failure going into my field. I’d like to think I’m smart enough to be prominent, but it’s irrational not to check first.
Thanks for the information; you might have just saved me a lot of trouble down the line, one way or the other.
I’d be very careful generalizing from that study to the practice of science today. Science in the 1950s was VERY different, the length of time to the phd was shorter, postdocs were very rare, and almost everyone stepped into a research faculty position almost immediately.
In today’s world, staying in science is much harder- there are lots of grad students competing for many postdocs competing for few permanent science positions. In today’s world, things like conscientiousness, organization skills,etc (grant writing is now a huge part of the job) play a much larger role in eventually landing a job in the past, and luck is a much bigger driver (whether a given avenue of exploration pays off requires a lot of luck. Selecting people whose experiments ALWAYS work is just grabbing people who have been both good AND lucky). It would surprise me if the worsening science career hasn’t changed the make up of an ‘eminent scientist’.
At the same time, all of those points except the luck one could be presented as evidence that the IQ required to be eminent has increased rather than the converse. Grant writing and schmoozing are at least partially a function of verbal IQ, IQ in general strongly predicts academic success in grad school, and competition tends to winnow out the poor performers a lot more than the strong.
Not that I really disagree, I just don’t see it as particularly persuasive.
That’s just one of the unavoidable frustrations of human nature though; an experiment which dis-confirms it’s hypothesis worked perfectly, it just isn’t human nature to notice negatives.
I disagree for several reasons. Mostly, conscientiousness, conformity,etc are personality traits that aren’t strongly correlated with IQ (conscientiousness may even be slightly negatively correlated).
Would it surprise you to know that the most highly regarded grad students in my physics program all left physics? They had a great deal of success before and in grad school (I went to a top 5 program) , but left because they didn’t want to deal with the administrative/grant stuff, and because they didn’t want to spend years at low pay.
I’d argue that successful career in science is selecting for some threshhold IQ and then much more strongly for a personality type.
No kidding.
Are you American? If you’ve taken the SAT, you can get a pretty good estimate of your IQ here.
Mensa apparently doesn’t consider the SAT to have a high-enough g loading to be useful as an intelligence test after 1994. Although the website’s figure are certainly encouraging, it’s probably best to take them with a bit of salt.
True, but note that, in contrast with Mensa, the Triple Nine Society continued to accept scores on tests taken up through 2005, though with a higher cutoff (of 1520) than on pre-1995 tests (1450).
Also, SAT scores in 2004 were found to have a correlation of about .8 with a battery of IQ tests, which I believe is on par with the correlations IQ tests have with each other. So the SAT really does seem to be an IQ test (and an extremely well-normed one at that if you consider their sample size, though perhaps not as highly g-loaded as the best, like Raven’s).
But yeah, if you want to have high confidence in a score, probably taking additional tests would be the best bet. Here’s a list of high-ceiling tests, though I don’t know if any of them are particularly well-normed or validated.
Is this what you intended to say? “Diminishing returns” seems to apply at the bottom the scale you mention. You’ve already selected the part where returns have started diminishing. Sometimes it is claimed that that at the extreme top the returns are negative. Is that what you mean?
Yeah, that’s just me trying to do everything in one draft. Editing really is the better part of clear writing.
I meant something along the lines of “I’ve heard it has diminishing returns and potentially [, probably due to how it affects metabolic needs and rate of maturation] even negative returns at the high end.”
Most IQ tests are not very well calibrated above 120ish, because the number of people in the reference sample that scored much higher is rather low. It’s also the case that achievement is a function of several different factors, which will probably become the limiting factor for most people at IQs higher than 120. That said, it does seem that in physics, first-tier physicists score better on cognitive tests than second-tier physicists, which suggests that additional IQ is still useful for achievement in the most cognitively demanding fields. It seems likely that augmented humans who do several times better than current humans on cognitive tests will also be able to achieve several times as much in cognitively demanding fields.
First, IQ tests don’t go to 250 :-) Generally speaking standard IQ tests have poor resolution in the tails—they cannot reliably identify whether you have the IQ of, say, 170 or 190. At some point all you can say is something along the lines of “this person is in the top 0.1% of people we have tested” and leave it at that.
Second, “achievement” is a very fuzzy word. People mean very different things by it. And other than by money it’s hard to measure.