That may be the case, but I still don’t find the explanation satisfactory from the point of view of the classic general intelligence theory (not that I have a better alternative, though).
To clarify, the traditional theory of general intelligence, which is taken as a background assumption in most IQ-related research, assumes that general intelligence is normally distributed in the general population, and any reasonable measure of it will be highly correlated with IQ test scores (which are themselves artificially crafted to produce a normal distribution of scores). Moreover, it assumes that people whose intellects stand out as strikingly brilliant are drawn—as a necessary condition, and not too far from sufficient—from the pool of those whose general intelligence is exceptionally high. Now, if the scores on IQ tests are rising, but there is no visible increase in outstanding genius, it could mean one or more of these things (or something else I’m not aware of?):
We’re applying higher criteria for genius. But are we really? Has the number of people at the level of von Neumann, Ramanujan, or Goedel really increased by two orders of magnitude since their time, as it should have if the distribution of general intelligence has simply moved up by 2SD since their time? (Note that for any increase in average, ceteris paribus, the increase in the rate of genius should be greater the higher the threshold we’re looking at!)
The average has moved up, but the variance has shrunk. But this would have to be implausibly extreme shrinkage, since the average of IQ scores today is roughly at the z-score of +2 from two generations ago.
The modern culture is making common folks smarter, but it drags geniuses down. I believe there might be some truth to this. The pop culture everyone’s supposed to follow, however trashy, has gotten more demanding mentally, but true intellectual pursuits have lost a lot of status compared to the past. Still, such effects can’t explain the severity of the effect—remember, the Flynn increase is greater than the difference between borderline retardation and being above average in the way the scores are used for diagnostics!
The IQ scores say a lot about people who are average or below average, but not much about smart people. This seems like the most plausible option to me, and the only one compatible with evidence. But this means that the standard model based on the normal distribution is seriously broken when it comes to the right side of the distribution, and it also makes the results of many heritability studies much more murky.
All in all, the situation is confusing, and unlikely to get clearer in the near future.
This study (which HughRistik originally pointed to here) suggests that IQ distribution might be better modeled as two overlapping normal distributions, one for people who are not suffering from any conditions disrupting normal intelligence development (such as disease, nutritional problems, maternal drug or alcohol use during pregnancy, etc.) and the other for those who suffered developmental impairment. If this model has some validity the Flynn effect could perhaps be explained as a reduction in the number of people falling into the ‘impaired’ distribution due to improved health and nutrition in the population. This would seem to explain an increase in the average score without a corresponding increase in the number of ‘geniuses’.
We’re applying higher criteria for genius. But are we really?
I think this is more likely than not, but I couldn’t quantify it. I think it’s more likely for the simple reason that what earlier geniuses (like von Neumann etc.) did has already been done. To me, that implies the genius bar has been raised, in absolute terms, at least in the hard sciences and math.
The average has moved up, but the variance has shrunk. But this would have to be implausibly extreme shrinkage,
Agree.
The modern culture is making common folks smarter, but it drags geniuses down. I believe there might be some truth to this. The pop culture everyone’s supposed to follow, however trashy, has gotten more demanding mentally, but true intellectual pursuits have lost a lot of status compared to the past. Still, such effects can’t explain the severity of the effect --
Agree. It’s hard for me to imagine many geniuses getting derailed just by trash TV and ostracism.
The IQ scores say a lot about people who are average or below average, but not much about smart people. This seems like the most plausible option to me, and the only one compatible with evidence.
I believe IQ still correlates positively with performance among very high-achievers, just not as well as for normal people. The biggest factor here might be touched on in your second paragraph:
Moreover, it assumes that people whose intellects stand out as strikingly brilliant are drawn—as a necessary condition, and not too far from sufficient—from the pool of those whose general intelligence is exceptionally high.
I would bet that the standouts you’re talking about would have higher average IQ, but would not actually be ‘exceptionally’ high, because IQ doesn’t correlate that well with success. Also, many of the geniuses we’re thinking of would probably be specialists, and it’s harder to track specialized performance with the (relatively) generalist metric of IQ. If the IQ threshold for genius is lower than you think, an upward shift in the mean makes less difference. (Of course it can’t explain the effect away entirely; something else is happening. But it could be a part.)
I think it’s more likely for the simple reason that what earlier geniuses (like von Neumann etc.) did has already been done. To me, that implies the genius bar has been raised, in absolute terms, at least in the hard sciences and math.
That could well be the case. However, it fails to explain the lack of apparent genius at lower educational stages. For example, if you look at a 30 year period in the second half of the 20th century, the standard primary and high school math programs probably didn’t change dramatically during this time, and they certainly didn’t become much harder. Moreover, one could find many older math teachers who worked with successive generations throughout this period—in which the Flynn IQ increase was above 1SD in many countries. If the number of young potential von Neumanns increased drastically during this period, as it should have according to the simple normal distribution model, then the teachers should have been struck by how more and more kids find the standard math programs insultingly easy. This would be true even if these potential von Neumanns have subsequently found it impossible to make the same impact as him because all but the highest-hanging fruit is now gone.
I would bet that the standouts you’re talking about would have higher average IQ, but would not actually be ‘exceptionally’ high, because IQ doesn’t correlate that well with success.
Yes, that’s basically what I meant when I speculated that IQ might be significantly informative about intellectually average and below-average people, but much less about above-average ones. Unfortunately, I think we’ll have to wait for further major advances in brain science to make any conclusions beyond speculation there. Psychometrics suffers from too many complications to be of much further use in answering such questions (and the politicization of the field doesn’t help either, of course).
in which the Flynn IQ increase was above 1SD in many countries. If the number of young potential von Neumanns increased dramatically during this period, as it should have according to the simple normal distribution model, then the teachers should have been struck by how more and more kids find the standard math programs insultingly easy
Well, as discussed above, there are many interpretations of the Flynn effect, and it’s not clear that the IQ increase actually corresponds to a gain in intelligence. From what Flynn has written, it seems most likely to be a measurement problem of sorts, in which case the number of “potential Von Neumanns” would not increase.
I think education not becoming harder in the earlier grades is a strong misnomer. My parents did punctuation symbols in their grade 5 curriculum, I did it in grade 3, It’s currently done in Kindergarten or Grade 1, and many other topics have similar track records.
As for high school math programs, many parts of the world have had a shift from a 13 grade program to a 12 grade program which compresses a lot of material.
I think a bigger factor may be we are better at recognizing and marketing talent. The kids who find high school mathematics a complete joke in grade 8 are getting scholarships elsewhere.
Many of my peers in undergraduate mathematics had done work with a professor at a university in their home city during their high school years, a sizable number had private school scholarships based on their talents. So perhaps these individuals are seldom present in ordinary standard math programs.
For example, if you look at a 30 year period in the second half of the 20th century, the standard primary and high school math programs probably didn’t change dramatically during this time, and they certainly didn’t become much harder.
I’m not so sure. Here’s a 2005 paper (‘Rising mean IQ: Cognitive demand of mathematics education for young children, population exposure to formal schooling, and the neurobiology of the prefrontal cortex’) suggesting that ‘cognitive demands of mathematical curricula’ in the US increased from about 1950.
Anecdotally, I remember occasionally surprising my parents by telling them about what I was learning in math—my schools’ math syllabuses apparently went faster than my parents’.
The question is if this effect (and/or effects like it in other school subjects) would be enough to mask the Flynn effect at younger ages; I guess it could be enough to partly mask it but not wholly mask it, in which case there are other explanations at work too. Maybe the Flynn effect is less in children than adults as well.
Unfortunately, I think we’ll have to wait for further major advances in brain science to make any conclusions beyond speculation there. Psychometrics suffers from too many complications to be of much further use in answering such questions (and the politicization of the field doesn’t help much either, of course).
Neuroscience could certainly help, but I would think one could make a good start just by repeatedly IQ-testing a huge number of kids through childhood, tracking them into middle age, plotting child IQ against adult achievement, and drawing a lowess regression line through it. If the line starts out relatively steep but flattens out with increasing IQ, you and me are right: IQ isn’t that informative about high flyers. I wouldn’t be that surprised if someone hadn’t already done something like this with the Project Talent data or some other big database.
Sputnik was a huge shock to the U.S., causing fear that the Soviet Union would eventually overwhelm or eclipse the U.S. One of the results of that fear was the enrollment of math professors in the design of a new model math curriculum called the New Math, which was widely deployed and in most places where it was deployed represented a sharp break with past math curricula. Elementary-school children were taught things like how to do addition in bases other than ten. The “laws of algebra” (e.g., the commutativity property) were introduced much earlier than they had been in the past. The New Math was a frequent topic of popular news articles and news segments in the late 1960s, probably because of the bewilderment of parents who attempted to help their children with math homework.
I was an elementary-school student in Massachusetts public schools in the 1960s, and this New Math was my favorite part of an otherwise uninspired factory-style elementary-school education, so I salute the Soviet space program of the 1950s for shocking certain elements of the educational establishment of my country out of its complacency.
Do we know if the early start actually led to more talent in math and science when children of this age became adults? Or did we just end up with a lot of lawyers who learned and then forgot Calculus?
All I can tell you is that I am very good at math and science and that I am significantly less likely to have turned out that way if in elementary school, I had been taught a lot of calculational arithmetic and elementary-algebra skills with no coherent and thoughtful attempt to teach the “concepts” or the “broader understanding”. My formal educational was pretty crappy, and I would have been much better off if someone’d just given me a small office or a desk and a chair in a quiet place and access to books at the end of elementary school, so I could have skipped the whole secondary-school experience like Eliezer did, but the elementary-school math was very well done, not because the teachers were particularly inspired but rather because the design and integrated nature of the whole curriculum or plan of tuition.
Also, let us not lose sight of my reason for writing, which is to present evidence that at least in the U.S., math education for the average child changed drastically during the 20th Century.
It’s conceivable that there are institutional barriers to genius expressing itself—partly that there really is more knowledge to be assimilated before one can do original work, and partly that chasing grants just sucks up too much time and makes it less likely for people to work on unfashionable angles.
Still, it’s not like historical geniuses all grew up as pampered aristocrats left to pursue whatever they liked. Many of them grew up as poor commoners destined for an entirely unremarkable life, but their exceptional brightness as kids caught the attention of the local teacher, priest, or some other educated and influential person who happened to be around, and who then used his influence to open an exceptional career path for them. Thus, if the distribution of kids’ general intelligence is really going up all the way, we’d expect teachers and professors to report a dramatic increase in the number of such brilliant students, but that’s apparently not the case.
Moreover, many historical geniuses had to overcome far greater hurdles than having to chase grants and learn a lot before reaching competence for original work. Here I mean not just the regular life hardships, like when Tesla had to dig ditches for a living or when Ramanujan couldn’t afford paper and pencil, but also the intellectual hurdles like having to become professionally proficient in the predominant language of science (whether English today or German, French, or Latin in the past), which can take at least as much intellectual effort as studying a whole subfield of science thoroughly.
So, while your hypothesis makes sense, I don’t think it can fully explain the puzzle.
Many high intelligence situations involve disorders that also have as an effect anti-social behavior. Academia is highly geared against this in some cases going so far as to evaluate people’s chances for success in a PhD based on their ability to form working relationships with a peer group during their MSc. Travel is easier and correspondence is far more personal.
Would the mathematicians of the past have been as interested in this model? Perhaps some of them were the type of people that were happy to correspond by mail but found communicating face to face awkward. This wasn’t a big barrier to success in the past, but it is very difficult in modern academia (particularly with most positions in most fields being teaching + research).
Far enough, and I’m not even sure the “more knowledge required” is that strong an argument for some parts of math.
A scary possibility is that there are fewer people at the far right end of the bell curve. I have no idea what could case that effect, but we don’t know what makes for genius of the sort which does significant creative work.
It’s conceivable but unlikely that teachers’ ability to recognize extraordinary minds has declined.
Perhaps genius requires extraordinary effort, which is only worthwhile if you already have nothing to lose. So maybe the hardships and obstacles that previous highly intelligent people faced actually contributed to their eventual success.
There are still plenty of poor people, so lack of hardship doesn’t seem to be the problem.
IIRC, there’s a theory that you get more genius when political entities are small and competing—hence the Renaissance. However, that’s generalizing from one example—any clues plus or minus for the theory?
There are always people with nothing to lose—it may be less common to have elites with something to win.
That may be the case, but I still don’t find the explanation satisfactory from the point of view of the classic general intelligence theory (not that I have a better alternative, though).
To clarify, the traditional theory of general intelligence, which is taken as a background assumption in most IQ-related research, assumes that general intelligence is normally distributed in the general population, and any reasonable measure of it will be highly correlated with IQ test scores (which are themselves artificially crafted to produce a normal distribution of scores). Moreover, it assumes that people whose intellects stand out as strikingly brilliant are drawn—as a necessary condition, and not too far from sufficient—from the pool of those whose general intelligence is exceptionally high. Now, if the scores on IQ tests are rising, but there is no visible increase in outstanding genius, it could mean one or more of these things (or something else I’m not aware of?):
We’re applying higher criteria for genius. But are we really? Has the number of people at the level of von Neumann, Ramanujan, or Goedel really increased by two orders of magnitude since their time, as it should have if the distribution of general intelligence has simply moved up by 2SD since their time? (Note that for any increase in average, ceteris paribus, the increase in the rate of genius should be greater the higher the threshold we’re looking at!)
The average has moved up, but the variance has shrunk. But this would have to be implausibly extreme shrinkage, since the average of IQ scores today is roughly at the z-score of +2 from two generations ago.
The modern culture is making common folks smarter, but it drags geniuses down. I believe there might be some truth to this. The pop culture everyone’s supposed to follow, however trashy, has gotten more demanding mentally, but true intellectual pursuits have lost a lot of status compared to the past. Still, such effects can’t explain the severity of the effect—remember, the Flynn increase is greater than the difference between borderline retardation and being above average in the way the scores are used for diagnostics!
The IQ scores say a lot about people who are average or below average, but not much about smart people. This seems like the most plausible option to me, and the only one compatible with evidence. But this means that the standard model based on the normal distribution is seriously broken when it comes to the right side of the distribution, and it also makes the results of many heritability studies much more murky.
All in all, the situation is confusing, and unlikely to get clearer in the near future.
This study (which HughRistik originally pointed to here) suggests that IQ distribution might be better modeled as two overlapping normal distributions, one for people who are not suffering from any conditions disrupting normal intelligence development (such as disease, nutritional problems, maternal drug or alcohol use during pregnancy, etc.) and the other for those who suffered developmental impairment. If this model has some validity the Flynn effect could perhaps be explained as a reduction in the number of people falling into the ‘impaired’ distribution due to improved health and nutrition in the population. This would seem to explain an increase in the average score without a corresponding increase in the number of ‘geniuses’.
I think this is more likely than not, but I couldn’t quantify it. I think it’s more likely for the simple reason that what earlier geniuses (like von Neumann etc.) did has already been done. To me, that implies the genius bar has been raised, in absolute terms, at least in the hard sciences and math.
Agree.
Agree. It’s hard for me to imagine many geniuses getting derailed just by trash TV and ostracism.
I believe IQ still correlates positively with performance among very high-achievers, just not as well as for normal people. The biggest factor here might be touched on in your second paragraph:
I would bet that the standouts you’re talking about would have higher average IQ, but would not actually be ‘exceptionally’ high, because IQ doesn’t correlate that well with success. Also, many of the geniuses we’re thinking of would probably be specialists, and it’s harder to track specialized performance with the (relatively) generalist metric of IQ. If the IQ threshold for genius is lower than you think, an upward shift in the mean makes less difference. (Of course it can’t explain the effect away entirely; something else is happening. But it could be a part.)
cupholder:
That could well be the case. However, it fails to explain the lack of apparent genius at lower educational stages. For example, if you look at a 30 year period in the second half of the 20th century, the standard primary and high school math programs probably didn’t change dramatically during this time, and they certainly didn’t become much harder. Moreover, one could find many older math teachers who worked with successive generations throughout this period—in which the Flynn IQ increase was above 1SD in many countries. If the number of young potential von Neumanns increased drastically during this period, as it should have according to the simple normal distribution model, then the teachers should have been struck by how more and more kids find the standard math programs insultingly easy. This would be true even if these potential von Neumanns have subsequently found it impossible to make the same impact as him because all but the highest-hanging fruit is now gone.
Yes, that’s basically what I meant when I speculated that IQ might be significantly informative about intellectually average and below-average people, but much less about above-average ones. Unfortunately, I think we’ll have to wait for further major advances in brain science to make any conclusions beyond speculation there. Psychometrics suffers from too many complications to be of much further use in answering such questions (and the politicization of the field doesn’t help either, of course).
Well, as discussed above, there are many interpretations of the Flynn effect, and it’s not clear that the IQ increase actually corresponds to a gain in intelligence. From what Flynn has written, it seems most likely to be a measurement problem of sorts, in which case the number of “potential Von Neumanns” would not increase.
I think education not becoming harder in the earlier grades is a strong misnomer. My parents did punctuation symbols in their grade 5 curriculum, I did it in grade 3, It’s currently done in Kindergarten or Grade 1, and many other topics have similar track records.
As for high school math programs, many parts of the world have had a shift from a 13 grade program to a 12 grade program which compresses a lot of material.
I think a bigger factor may be we are better at recognizing and marketing talent. The kids who find high school mathematics a complete joke in grade 8 are getting scholarships elsewhere.
Many of my peers in undergraduate mathematics had done work with a professor at a university in their home city during their high school years, a sizable number had private school scholarships based on their talents. So perhaps these individuals are seldom present in ordinary standard math programs.
I’m not so sure. Here’s a 2005 paper (‘Rising mean IQ: Cognitive demand of mathematics education for young children, population exposure to formal schooling, and the neurobiology of the prefrontal cortex’) suggesting that ‘cognitive demands of mathematical curricula’ in the US increased from about 1950.
Anecdotally, I remember occasionally surprising my parents by telling them about what I was learning in math—my schools’ math syllabuses apparently went faster than my parents’.
The question is if this effect (and/or effects like it in other school subjects) would be enough to mask the Flynn effect at younger ages; I guess it could be enough to partly mask it but not wholly mask it, in which case there are other explanations at work too. Maybe the Flynn effect is less in children than adults as well.
Neuroscience could certainly help, but I would think one could make a good start just by repeatedly IQ-testing a huge number of kids through childhood, tracking them into middle age, plotting child IQ against adult achievement, and drawing a lowess regression line through it. If the line starts out relatively steep but flattens out with increasing IQ, you and me are right: IQ isn’t that informative about high flyers. I wouldn’t be that surprised if someone hadn’t already done something like this with the Project Talent data or some other big database.
Sputnik was a huge shock to the U.S., causing fear that the Soviet Union would eventually overwhelm or eclipse the U.S. One of the results of that fear was the enrollment of math professors in the design of a new model math curriculum called the New Math, which was widely deployed and in most places where it was deployed represented a sharp break with past math curricula. Elementary-school children were taught things like how to do addition in bases other than ten. The “laws of algebra” (e.g., the commutativity property) were introduced much earlier than they had been in the past. The New Math was a frequent topic of popular news articles and news segments in the late 1960s, probably because of the bewilderment of parents who attempted to help their children with math homework.
I was an elementary-school student in Massachusetts public schools in the 1960s, and this New Math was my favorite part of an otherwise uninspired factory-style elementary-school education, so I salute the Soviet space program of the 1950s for shocking certain elements of the educational establishment of my country out of its complacency.
Do we know if the early start actually led to more talent in math and science when children of this age became adults? Or did we just end up with a lot of lawyers who learned and then forgot Calculus?
All I can tell you is that I am very good at math and science and that I am significantly less likely to have turned out that way if in elementary school, I had been taught a lot of calculational arithmetic and elementary-algebra skills with no coherent and thoughtful attempt to teach the “concepts” or the “broader understanding”. My formal educational was pretty crappy, and I would have been much better off if someone’d just given me a small office or a desk and a chair in a quiet place and access to books at the end of elementary school, so I could have skipped the whole secondary-school experience like Eliezer did, but the elementary-school math was very well done, not because the teachers were particularly inspired but rather because the design and integrated nature of the whole curriculum or plan of tuition.
Also, let us not lose sight of my reason for writing, which is to present evidence that at least in the U.S., math education for the average child changed drastically during the 20th Century.
It’s conceivable that there are institutional barriers to genius expressing itself—partly that there really is more knowledge to be assimilated before one can do original work, and partly that chasing grants just sucks up too much time and makes it less likely for people to work on unfashionable angles.
Still, it’s not like historical geniuses all grew up as pampered aristocrats left to pursue whatever they liked. Many of them grew up as poor commoners destined for an entirely unremarkable life, but their exceptional brightness as kids caught the attention of the local teacher, priest, or some other educated and influential person who happened to be around, and who then used his influence to open an exceptional career path for them. Thus, if the distribution of kids’ general intelligence is really going up all the way, we’d expect teachers and professors to report a dramatic increase in the number of such brilliant students, but that’s apparently not the case.
Moreover, many historical geniuses had to overcome far greater hurdles than having to chase grants and learn a lot before reaching competence for original work. Here I mean not just the regular life hardships, like when Tesla had to dig ditches for a living or when Ramanujan couldn’t afford paper and pencil, but also the intellectual hurdles like having to become professionally proficient in the predominant language of science (whether English today or German, French, or Latin in the past), which can take at least as much intellectual effort as studying a whole subfield of science thoroughly.
So, while your hypothesis makes sense, I don’t think it can fully explain the puzzle.
It could also be communications.
Many high intelligence situations involve disorders that also have as an effect anti-social behavior. Academia is highly geared against this in some cases going so far as to evaluate people’s chances for success in a PhD based on their ability to form working relationships with a peer group during their MSc. Travel is easier and correspondence is far more personal.
Would the mathematicians of the past have been as interested in this model? Perhaps some of them were the type of people that were happy to correspond by mail but found communicating face to face awkward. This wasn’t a big barrier to success in the past, but it is very difficult in modern academia (particularly with most positions in most fields being teaching + research).
Far enough, and I’m not even sure the “more knowledge required” is that strong an argument for some parts of math.
A scary possibility is that there are fewer people at the far right end of the bell curve. I have no idea what could case that effect, but we don’t know what makes for genius of the sort which does significant creative work.
It’s conceivable but unlikely that teachers’ ability to recognize extraordinary minds has declined.
Perhaps genius requires extraordinary effort, which is only worthwhile if you already have nothing to lose. So maybe the hardships and obstacles that previous highly intelligent people faced actually contributed to their eventual success.
There are still plenty of poor people, so lack of hardship doesn’t seem to be the problem.
IIRC, there’s a theory that you get more genius when political entities are small and competing—hence the Renaissance. However, that’s generalizing from one example—any clues plus or minus for the theory?
There are always people with nothing to lose—it may be less common to have elites with something to win.