Saturday, March 01, 2014

The Neanderthal Problem

Update (2020): See also The Inheritors and The Grisly Folk: H.G. Wells and William Golding on Neanderthals.

The NYTimes magazine describes efforts to resurrect extinct species such as mammoths. Let's suppose this is possible. Perhaps it will even be possible with Neanderthals, Denisovans, Homo Erectus and other pre-modern human types.

Consider the following thought experiment. Imagine thousands of Neanderthals on some privately held land in Siberia, perhaps the secret project of a reclusive billionaire oligarch.

It's very likely these Neanderthals, although able to interbreed with humans, and probably capable of speech, will be on average considerably less intelligent than humans. If I had to guess I would suppose their average adult IQ to be about 70, or -2 SD relative to modern humans. You might wonder how they could have survived for 300k+ years with such modest intelligence, but based on my experiences with 5-10 year old kids I don't think that a sub-adult level of maximum intelligence precludes the ability to form societies and function as hunter-gatherers. (Apes survive with even less cognitive ability.) I just don't think that higher developments (e.g., invention of writing) are likely for such a population. What Homo Sapiens accomplished in 50-100k years far outstrips Neanderthal accomplishments over a much longer period of time.

Modern humans differ from each other at about 1 in 1000 places in the genome, whereas a Neanderthal and a human differ at a few per 1000 places. Some subset of these additional differences cause them to be broader, more powerfully muscled, and, most likely, less intelligent. (See Neanderthals dumb?)

Now to the problem: how should we integrate these Neanderthals into modern society?

Perhaps we should not integrate them -- better to leave them alone on protected lands, to live their ''natural'' (= nasty, brutish and short?) lives. But what if some Neanderthals express the wish to join our society? How should we best help them?

I think it's likely that no amount of special education or training will allow average Neanderthals to be successful in cognitively demanding jobs. They might face significant discrimination, given their appearance.

However, let us suppose that in this future the technology exists to modify the genes which cause the cognitive gap between moderns and Neanderthals. Suppose it is possible, through genetic engineering, to modify the genomes of Neanderthal embryos, causing their brains to develop as ours do. Would it not be our moral duty to make this modification available to Neanderthal parents who want it?

Extra credit questions:

1) Is it "racist" to make the assumptions used in our hypothetical?

2) Is it also our moral duty to make similar modifications available to human parents who happen to be well below average in cognitive ability?

See also Darwin's Savages.


Iamexpert said...

Their genetic IQ's would have been a lot higher than 70 to have survived in such cold climates. The two factors that have driven modern Northern Eurasian IQ so high (100+) has been the cognitive challenge of adapting to cold climates (which drove brain size way up) and the post-agriculture population explosion (which increased the odds of rare neurological efficiency mutations which increased IQ by about 1 SD independent of brain size). If I had to guess I would say Neanderthals had IQ resembling modern arctic people (i.e. 91), another pre-agriculture big brained cold adapted population.

Richard Seiter said...

On a tangent, can we make any inferences about the intelligence of other cold climate animals? How exactly are polar bears different from brown bears?

ahd said...

Why do you suppose 5-10y old kids have a sub-adult level of maximum intelligence? They haven't yet acquired knowledge and skills, but they're just as intelligent as they will be as adults, no? Also, why do you suppose that the ability to form societies and be hunter-gatherers is strongly dependent on intelligence? Lots of animals have social structure without being smart. It's not particularly germane to the point that you're making, but it just jumped out at me when I read it...

mzso said...

"moral duty" What a crappy name for ideology...

Anyway they have a proper place in the zoo.

Iamexpert said...

While it's true that children have less experience than adults, they are also less intelligent. They have smaller less developed brains and even on novel problems that don't require experience, they perform much worse than adults at their prime. About 70,000 years ago, humans had the intelligence of a modern Canadian seven year old. Upon experiencing the extreme ice age, northern Eurasian intellect increased to the level of a Canadian 13 year old. With such high intelligence, agriculture emerged in even inhospitable lands and population size exploded producing mutations that increased Northern intelligence to that of a Canadian 16 year old. However agriculture also brought severe malnutrition which shrunk intelligence back down to 12 year old levels. Only in the last century or so has nutrition improved enough for us to recover all the brain size and development we lost from agriculture, causing intelligence to boost to 16 year old levels (see the Flynn Effect).

ahd said...

interesting assertions. can you cite evidence? "smaller less developed" seems a red herring, given that we know so little about what's involved with intelligence: plenty of big creatures with big brains out there that we don't consider smart. are football players smarter than gymnasts? :D

Robert Ford said...

A) you're racist 2) people couldn't even handle that caveman sitcom because they thought it was racist d) Neanderthal's never went extinct, you should know that:

steve hsu said...

>> they're just as intelligent as they will be as adults, no? <<

My guess is no. I think it's not just learning and experience that make an 8 year old different from an adult. The brain grows and matures in a number of ways in the intervening years. My wild guess is that Neanderthal adults might have cognitive abilities similar to an 8 year old modern, and that that is not inconsistent with their ability to survive in cold environments.

Iamexpert said...

When you adjust for body size, humans have the biggest brains on earth.

ahd said...

all hail the tree shrew. much noise, little signal. maybe you need to change your username?

statsquatch said...

I think if you asked these three questions to the general
public (e.g., Oprah audience) or the elite (e.g., conclave of bioethicist) the
answer to each would be yes. Therein lays an apparent contradiction. Start with the third question, we currently
allow people to abort babies with known genetic defects (e.g., Downs) so how
could we not allow people to fix them prior to or after birth?

Given this, we would want to help these “people” but it is
also racist to think that they need fixing because of genetics. This apparent contradiction can be overcome
if you can convince yourself that difference between the human and Neanderthal “races”
are just social construct and, unlike genetics, should be ignored when making
medical decisions.

Iamexpert said...

The tree shrew may have the largest brain size/body size ratio, but humans have the largest encephalization quotient (EQ). The latter is the correct way to adjust for body size.

CalicoCat1 said...

What do you suppose the IQ was of the modern humans who lived at the time of the Neanderthals?

steve hsu said...

I should clarify that the -2 SD I use in the post is for Neanderthals living in modern society -- so, benefiting from good nutrition, education, etc. Neanderthals and early humans living under difficult conditions probably both have depressed abilities. But my guess is that there was a significant gap between the two groups, at least 1 SD or more.

nooffensebut said...

"Is it also our moral duty to make similar modifications available to
human parents who happen to be well below average in cognitive ability?"

This is nothing compared to the moral duty to help Africans decrease MAOA-2R prevalence. The direct effect of MAOA-2R on violent behavior is well supported on a theoretical basis due to established findings for Brunner syndrome, 5-HIAA metabolites, various MAOA-3R G-E interactions, and in vitro and small-sample MAOA-2R studies. MAOA-2R is about 22 times more common in African-American men than white men. The fact that scientists seem so reluctant to specifically study MAOA-2R, let alone help reduce its prevalence, should seriously be considered racial genocide.

mzso said...

Some sources would be nice for your "matter of fact" assertations as ahd also mentioned.

reservoir_dogs said...

I don't think you can extrapolate the difference between cold climate humans to other animal kingdom. The brain is a very costly organ, consuming enormous energy for its size. Animals in the arctic may rely on other features(like being able to hibernate longer) to survive the cold.

Iamexpert said...

My guess is that the European modern humans who lived contemporaneously with Neanderthals had IQ's of 87, about 13 points below Europeans today. I base this on the fact that the hunter/gatherers score almost 1 SD below agriculturalists of the same type. Thus East Asians score 14 points higher than their hunter/gather cousins in the arctic (the Inuit), and mainstream sub-Saharan African score about 13 points above bushmen/pygmies, so today's Europeans should score about 13 points higher than their hunter/gatherer ancestors. I think this difference is genetic, not environmental, because Cro-Magnon man was actually taller and bigger brained than early 20th century Europeans, suggesting better nutrition. I think the malnutrition of agriculture stunted brain growth, but we compensated as the huge population allowed new mutations to enhance our IQ's independently of brain size. Now with advances in modern nutrition, we not only have those genetic enhancements but are recovering our pre-agriculture brain size, hence the Flynn Effect.

Iamexpert said...

I'm not sure modern 8 year old intelligence is anywhere near enough to survive cold climates. To put it in perspective, Homo Erectus is thought to have the mental ability of a modern 7 year old based on a study that found that 7 year olds could be taught to make their tools. The study is a few decades old, so maybe it should be revised to a 6 year old (Flynn Effect). Jensen claims no Homo erects remains have been found in Northern Asia, probably because the climate was beyond their survival skills.

Terra said...

If I had to guess I would suppose their average adult IQ to be about 70, or -2 SD relative to modern humans.
Suppose it is possible, through genetic engineering, to modify the genomes of Neanderthal embryos, causing their brains to develop as ours do. Would it not be our moral duty to make this modification available to Neanderthal parents who want it?
One method of answering this question is by asking the following. Is it the moral obligation of Neanderthal parents to not choose Neanderthal partners over Homosapiens knowing that they will create people that will have a lower genetic mean IQ (ie. comparatively underdeveloped brain)?

Personally, no I do not believe it's our moral duty any more so, than it is for them to choose Homosapiens to produce offspring with.

1) Is it "racist" to make the assumptions used in our hypothetical?
From the World English Dictionary, if we're using definition #1:
1. the belief that races have distinctive cultural characteristics determined by hereditary factors and that this endows some races with an intrinsic superiority over others
Then yes, it's racist, especially if you agree with Darwin who would also be categorized as a racist.

If it's #2:
2. abusive or aggressive behaviour towards members of another race on the basis of such a belief
Then not necessarily, and I would hope not.

2) Is it also our moral duty to make similar modifications available to human parents who happen to be well below average in cognitive ability?
I take it that you are trying to build an ethical case that humanity has a moral obligation to fund research into improving our genetics?

Humans can already decide to choose partners who have significantly higher cognitive ability as partners to create offspring with (eg. physicists) that won't be well below average. For it to be our moral obligation, then isn't it our moral obligation to search genetically superior partners, and also shouldn't we remove ourselves from reproduction pool if we have inferior genes?

Trying to build a case that there's a moral obligation to make available this service, leads to all sorts of conclusions that I feel one could adamantly argue is far more immoral, usurping the moral high ground against the initial case.

Interesting hypothetical. I'm not entirely sure I'm right, but those are my current thoughts.

Iamexpert said...

See the wikipedia article on encephalization quotient which lists humans as having the biggest in a large chart you can't miss.

mzso said...

I was more interested in the historic IQ levels and IQ increase due to ice age.

Iamexpert said...

I wonder if you could estimate Neanderthal IQ by testing modern Europeans of varying degrees of Neanderthal admixtures. Let's say that the average European has 2% Neanderthal admixture and an IQ of 100. But let's assume Europeans with 4% Neanderthal admixture have IQ's of 99.5. From there could one mathematically extrapolate what IQ people with 100% Neanderthal admixture would have.

Iamexpert said...

A good source for all that is Richard Lynn's 2006 book which includes a chapter about how and why humans became smarter the further North they migrated.

LondonYoung said...

Intelligence seems not to be a good thing for survival as these little guys have learned

As for our descendants, the following was cut from The Time Machine for being too grim:

Bobdisqus said...

The crew at West Hunter were thinking on this, and yes your a racist. We can't even get our HS house in order. It seems we ought to start there before we tell the nice Neanderthal next door he is due for a tune up.

ahd said...

ok, i took the bait. i read the wikipedia article. it ends with a criticism: "Recent research indicates that whole brain size is a better measure of cognitive abilities than EQ for primates at least." the whole thing is dumb: if the premise of EQ is that X grams of brain mass or Y neurons are required for certain body functions and don't scale with size then you'd regress with an intercept not fit some cockamamie polynomial. silliness.

chartreuse1737 said...

"Would it not be our moral duty to make this modification available to Neanderthal parents who want it?

Extra credit questions:

1) Is it "racist" to make the assumptions used in our hypothetical?

2) Is it also our moral duty to make similar modifications available to
human parents who happen to be well below average in cognitive ability?"

yes. no. and yes.

i do trust my instinct however unfounded that people who look stupid are stupid. people who look like apes are stupid. but there are plenty of 100% europeans and 100% chinese that look dumber and are dumber than this guy

and, of course, at the far left of the bell curve reproduction is negligible. those with iqs in the bottom 2% for their population have far fewer children than those in the top 2%.

chartreuse1737 said...

and what about this guy, a famous danish footballer?

chartreuse1737 said...

but would neanderthal officers score higher than non-neanderthal enlisteds? that is supposing a neanderthal would have any score on an iq test at all. my dog can't even answer a single sat question correctly. so dumb. but the he can smell through 10 ft of lead.

chartreuse1737 said...

hasn't gs always preferred ascidians to the encephalized?

blankfein is quite short and now bearded for reasons unknowable. is he human or neanderthal?

LondonYoung said...

perhaps he is bearded because of a malfunction of the transporter?,_Mirror_(Star_Trek:_The_Original_Series)

JayMan said...

Very clever post... ;)

Iamexpert said...

Google "Neanderthals were too smart to survive", an article that argues that Neanderthals were smarter than humans

Matt Whitlam said...

And what if you are wrong? What if Neanderthals were more intelligent and the only reason that they went extinct was that they chose to interbreed with us? What if they had average IQ's of 150 and were more peaceful, non territorial, monogamous, and highly inter-group co-operative? What if they see how we are and what we have done to them and the planet and how they no longer exist because of us? What if we are the ones that are behaviorally flawed making wars, believing in imaginary Gods in the sky, trusting in a hierarchical system where we follow leaders who continuously lie to the very people who put them in power instead of following the kindest most sensible and logical individual who has the best intentions of doing what's right for the group? What if they chose their leader by who was the most selfless and intelligent person rather than the most selfish?. What if they see us as cruel for having a class system were the rich own all the resources of the earth and can do almost anything go almost anywhere while millions of our own same species die in horrific poverty.What if they were instinctively Nomadic and don't understand the Idea of property and ownership because they took what they needed from the earth and shared all amoungst their own group.? What if they don't understand patriotism and Nationalism and how we kill each other for imaginary dividing lines in the dirt that we call countries?What if they never had the delusional mind that 95% of us have that makes us believe in only what we are told to accept by our superiors and what if they saw the world as it is and never had the concept of religion. What if Neanderthals were the first actual real humans and modern humans in their time didn't exist, perhaps we are nothing more than hybrid Neanderthals who inherited the very intelligence and creativity we so proudly call ourselves superior with from them and then used it against them?, What if they were more human and humane than us? Most of the traits we call modern and advanced or superior are actually more primitive traits that can be traced back to earlier forms of humans that pre-date Neanderthals, Look at history it is always written by the winners not necessarily by the good,

mzso said...

"1. the belief that races have distinctive cultural characteristics
determined by hereditary factors and that this endows some races with an
intrinsic superiority over others
Then yes, it's racist, especially if you agree with Darwin who would also be categorized as a racist."

With this definition it would be better to call it "being right". This is true within different populations within different (poorly defined) races.

mzso said...

I highly doubt that's possible. Most of the neanderthal genome is gone. And since the disadvantageous stuff are selected against probably low iq genes would be gone too.

Terra said...

Unfortunately, "being right" and being "racist" aren't mutually exclusive by this definition. Stephen wrote "racist" in quotes, so I wasn't sure if he meant it by definition #1 or in a more casual way often associated with #2. Either way, I think we'd have to categorize those assumptions, along with Darwin, as racist or "racist".

Terra said...

I'm not sure why comment disappeared. I'm guessing it's some technical error, but I hope I didn't break some rule I'm unfamiliar with. I don't think so, but I apologize if that's the case Steve.

I'll restate that "being right" and being "racist" in making those assumptions aren't mutually exclusive. I'm very much willing to hear how it's not racist, and would personally root for myself to be wrong on that matter.

ahd said...

a couple of relevant question that you may know the answer to - i don't. are the iq tests given to kids different than those given to adults or, alternatively, is there a normalization applied to the raw scores that depends on age? if it turns out to be the same tests without any age-dependent normalization, then do the results show a significant dependence on age? this could be most easily seen by subsetting on those people who have been tested multiple times over the course of years to keep the test clean. no idea, really, but maybe you do...

steve hsu said...

For younger kids the tests themselves are different. Scores are normalized by age group and mean scores improve with age until early adulthood. In some studies of gifted kids they have them take the SAT early and normalize by age cohort. IIRC, a score that is 99.99th percentile for a 13 year old is much lower than the 99th percentile score of a 17 year old.

ahd said...

thanks. sat result doesn't surprise me because sat success clearly depends on ability + knowledge + practice, not just ability. but pattern recognition, next shape in sequence, etc. really do seem like knowledge-independent tests of some basic kinds of intelligence. surprising to me that there'd an age-dependence to such test scores. do i need to trash my preconception, or might a reasonable person think the iq tests also depend on knowledge or practice, as well as raw ability?

steve hsu said...

This might be of interest to you:

This type of test does not (at least superficially) rely on knowledge acquisition. On page 6 (Table 1) you can see age-dependent norms.

Of course in reality there is no perfect way to disentangle "ability developed through training/schooling" and "ability developed due to brain maturation".

botti said...

1) If you look at how existing disparities are viewed, then those assumptions about neanderthals would probably be described as r8cist.
2) If that technology existed I suppose governments would see it as necessary to offer it to everyone to create a level playing field & provide equal opportunity.
3) It would be interesting to see how long those who attribute disparities to privilege/oppression would be prepared to advocate genetic treatments to alleviate social inequality.

ahd said...


Iamexpert said...

Actually it's arguably quite easy to disentangle ability developed through training/schooling from ability developed through brain maturation. Think of the difference between scholastic tests like the SAT and culture reduced tests like Matrix reasoning, Block Design and Digit Span. The whole dichotomy of fluid and crystalized ability depends on the assumption that we can disentangle them.

panjoomby said...

what if neandertals were smarter than sapiens? of course "smartness doesn't exist - b/c that'd be "racist." sadly for egalitarians, "g" exists, so i prefer the term "empiricist."

given neandertal DNA exists to a small degree in Europe-types, & to a slightly larger (still small) degree in Asian people, & given neandertal DNA does NOT seem to exist in Africans -
do the scatter plot: a very modest positive correlation between neandertal DNA & "g" (or "IQ"). it's a no-brainer.

dxie48 said...

:) Did that some time ago.

Although so far the MCPH1 haplotype D has not been found from the limited neanderthal DNA data, the idea is interesting.

What intrigue me when I saw the general introgression data between neanderthal and modern populations from Sankararaman,

the numerical ranking and the geographical distribution for the respective populations roughly correlate with that for the OECD PISA data.

This does not constitute proof because of there is no concrete casuality, small data size and many assumptions used.

Substitting Shanghai for CHB, HK for CHS, Costa Rica for PUR, did not use US data for CEU and no relevant data for the African population (although the data should agree with the general trend).

Analysis for 10 cases

Correlation Matrix:
math12 1.0000
pct 0.7337 1.0000
Variable math12 pct

Regression Equation for math12:
math12 = 413.2 pct + -10.7802

Significance test for prediction of math12
Mult-R R-Squared SEest F(1,8) prob (F)
0.7337 0.5383 53.1797 9.3275 0.0157

The prob (F) value of 0.0157 is quite significant.

chartreuse1737 said...

sisn't you get the memo? that "whole dichotomy" is 100% bs.

those who keep talking as if fluid and crystallized intelligence referred to things obviously can't tell the difference between intension and extension.

chartreuse1737 said...

that question is totally meaningless unless what one means by it is: if these earlier humans were delivered as infants by a time traveling stork to an upper middle class family in minneapolis what would their scores be?

chartreuse1737 said...

who was pope before peter? have you stopped beating your wife?

chartreuse1737 said...

neanderthals didn't have an iq. it's a category mistake.

Iamexpert said...

That scientific America article you linked to is really stupid. Crystallized tests have high heritability because they're more reliable than on the spot problem solving, not because there's no difference between fluid & crystallized ability. We know from studies of aging that old people continue to perform well on crystalized tests of knowledge (vocabulary) even after their actual intelligence (as measured by fluid tests) is quite impaired.

TFD123 said...

My research shows that 90% of the commenters have missed the point. This is brilliant.

panjoomby said...

excellent job - i love you! seriously, good work.
it's somehow relaxing to know there are people out there smarter than i:)
thanks for the link, too.

panjoomby said...

scientific PC american should be ashamed of that article - within the actual scientific/academic field of ability measurement/psychometrics it's quite well established that the more cognitively complex the measure (i.e., the higher its "g" loading), the higher the heritability coefficient (& the larger the group mean differences -- coff -- which you may not want to know about). This is known through vast amounts of twin studies, which are (well, were) the only way to even begin to parse genetic vs. environmental components, etc. i'm sorry to say that, b/c your comment about time traveling storks was awesome! (seriously!)

chartreuse1737 said...

you didn't read the article. the study is by a dutchman. it's been the case forever that vocab is the most g-loaded.

chartreuse1737 said...

more bs. "even after their actual intelligence". what tests have been flynned the most? not vocab or arithmetic? on what tests did afrikaners score lower than british south africans in the 50s but son't any more? surely it was the culturally loaded ones? nope. it was the "fluid" ones.

calling FACTS pc and assuming that if there is a word and a sense then there is a thing to which it refers make me think your own g is not that high.

panjoomby said...

Gee, they left out the wechsler’s only high g/nonverbal subtest, Matrix Reasoning (“this shape goes to this shape like this one goes to”) because it wouldn’t fit their agenda – it would be low cultural yet high g – it would screw up their findings b/c research is consistent: the higher the g loading, the higher the heritability coefficient. That’s the consistently replicated finding in the field –- NOT this artificial fluid - crystallized dichotomy – carving nature at its joints – a high crystallized thing would need a lot of fluid, but a high fluid would have to be demonstrated within some culture –
gee look, they “measured” cultural loadings:) niiiice.

they use subtests from the old (bad) Wechsler, prone to being called unfair b/c all its verbal subtests were pretty cultural, & almost all the nonverbal subtests had verbal content, except for the very low g ones (coding, etc.) it was very cultural – but removing cultural demands doesn’t make anyone smarter (usually it makes the test predict worse. b/c you’re removing "g"– e.g., see the old K-ABC kerfuffle, with Jensen noting “yes, the black/white differences were lower b/c it didn’t have much g in it, which means it didn’t predict diddly” paraphrasing mine)

they hid certain things like black/white means are equal on digits forward (b/c that’s low g) & black/white means are disparate on digits backward - b/c that's high g (nothing to do with culture or how verbal, etc.) wonder why they hid that – oh wait – agenda – a willing media!

the truth is & always has been: high g-loading tests have high heritability coefficients. low g loading tests have lower heritability coefficients. But, knowing that in advance, means you can leave out what you want, use old tests that are highly cultural, make up your own cultural variable & get it to say what you want. & get the media excited – as they aren’t for the hundreds of studies that don’t support these one-off findings!!

This is the same parlor trick as was used on Australian aborigines – oh gee, they do poorly on "remember where the verbally labeled item is" but they do great on remember where the different
rocks are – culture or g - too bad we’re trying to predict success in the culture – you knew that – you pointed out the dumbness of time machine stork babies – we’re all stuck in a rapidly homogenizing culture & it does us no good to use tests that predict success in a 50,000 year old culture – you knew that already! gahh! you got me to read a stupid article! yahghhH!

Iamexpert said...

The reason tests like vocab and arithmetic show limited Flynn Effect is because the Flynn Effect reflects an actual rise in brain size & neurological development that has occurred over the 20th century, and thus it shows up best on direct fluid measures of actual intelligence (i.e. Raven, Similarities) not crystallized measures of knowledge (vocab, arithmetic, SATs). Now in homogenous cultures, crystallized knowledge tests (because they're so reliable and stable) may correlate better with intelligence than actual intelligence tests, but they are an INDIRECT measure. Not sure why this is so hard for you to grasp.

chartreuse1737 said...

gee. you have no idea what you're talking about, so i stopped reading.

"matrix reasoning" is a new addition. how many studies in how many countries on its reliability and g-loading? the ravens is the least correlated with other self-described iq tests, that is, of all self-described iq tests. it is not a battery, but only one sort of test. it is the most flynned. yet klansmen claim it's the most g-loaded. whatever. leave the intelligence research to those with higher iqs than you.

Iamexpert said...

Chartreuse, the distinction between crystallized and fluid ability is very much valid and all your attempts to debunk it here have been very easily countered.

chartreuse1737 said...

a pair of typical hereditist iq mongers.

chartreuse1737 said...

if by "and all your attempts to debunk it here have been very easily countered" you mean "not even understood or addressed let alone countered" i agree.

maybe you should practice on the n-back a little more.

chartreuse1737 said...

here. i did your work for you. here are g-loadings averaged over studies corrected for reliability. guess which subtest still comes out on top? hint: it's vocabulary for children and adults. followed by all the other most culturally loaded subtests. here's a table summarizing the data.

there ARE differences between the tests categorized as fluid and those categorized as crystallized. there are difference in the parts of the brain used. BUT that difference is NOT fluid or crystallized. ALL of the putative fluid tests are IN FACT testing aquired abilities. there is a real difference between visua-spatial and verbal intelligence however.

chartreuse1737 said...

but i took the liberty of correcting the heritabilities for reliability which requires division by the reliability rather than sqrt(reliability). here's the result:



Block Design






Digit Span


Object Assembly






Digit Symbol (coding)


Picture Arrangement


Picture Completion


chartreuse1737 said...

Chartreuse, anything you could say, I've thought of it twice. (by which i assume you mean have never thought of) The herritabilities (sic.)(corrected for reliability) do not even include the two most g loaded Wechsler fluid tests (figure weights, matrix reasoning) (these are brand new. how many studies have been done? how can the ravens be the LEAST correlated with other self-described iq tests?). All you've shown is that verbal ability is more herritabie (sic.) than spatial ability and/or that g loaded tests are more heritable than less g loaded tests. How does that falsify the crystallized fluid dichotomy?(the dichotomy is unfalsifiable then)( Note, fluid tests can be verbal and crystallized tests can be spatial.(can be theoretically but never are IN FACT.) If anything fluid tests should be less heritable because they reflect how much intelligence one currently has while crystallized tessts reflect how much intelligence one used to have before environmental insults to the brain accumulated (i.e. alcohol, drugs, head injuries, medication, etc). In addition, it's well documented that verbal and scholastic abilities are much more resistant to prenatal malnutrition (and 1962 dutch recruits' ravens were totally immune to the effects of famine when they were in the womb or infants)which stunts brain size and intelligence. "fluid" intelligence DOES NOT EXIST. every test will measure experience and what one has made from it, or the extent to which one can make anything of it at all. the well-nourished child who is raised by wolves will not have the same "fluid intelligence" as his counterpart who is raised bu upmc parents in a developed country.

Iamexpert said...

I agree that no test is 100% fluid, but many are close enough to make it a useful meaningful concept. A child raised by wolves might at first flunk a fluid test, but after a few weeks of domestication, fluid tests would reflect his biological potential. By contrast he may never reach his potential on the SAT.

I agree that among culturally homogenous people, crystallized tests are often a better measure of intelligence, but there are many situations where only fluid tests are appropriate.

chartreuse1737 said...

not that any child could be raised by wolves. BUT, "A child raised by wolves might at first flunk a fluid test, but after a
few weeks of domestication, fluid tests would reflect his biological

IS the DUMBEST thing i've EVER heard.

there is a part of violinists brains which is enlarged as a result of their violin-ing. environment, not just food, can be nutritious or not. whatever the test save perhaps reaction time, ects, etc. (but likely not even those) will test the extent to which the brain has developed to play the metaphorical violin. and this is crystallized ability, even if it can't be put into words.

Stevie Mac said...

"not that any child could be raised by wolves". A child could be raised by dogs so maybe a child could be raised by wolves.

chartreuse1737 said...


but if not age 22 is quite a long time from her first six years. i wonder how she'd do on the matrix reasoning?

chartreuse1737 said...

you are polite and not abrasive, but you're actually arguing against yourself. and i'm sure that the correlation between fischer random rating and standard rating is near 1.

it goes for you and jensen and all y'all:

Iamexpert said...

Well a fluid test by definition is something you've virtually never done before. Fluid intelligence is defined as NOVEL problem solving. Once you've practiced it, it's no longer a valid measure of your intelligence.

Fluid intelligence can also be defined as the ability to learn, while crystallized intelligence is how much you have learned. Obviously they're highly correlated since how much you've learned is largely a function of your ability to learn. But fluid tests attempt to directly measure your ability to learn by giving you a novel problem to figure out on the spot while crystallized tests just infer your ability to learn indirectly by measuring your acquitted knowledge. Fluid tests are clearly more accurate for culturally heterogeneous comparisons, but among the culturally homogenous, the indirect approach might work better since acquired knowledge over a lifetime averages out all the day to day fluctuations in fluid performance caused by sleep deprivation, alcohol, drugs, head injuries, motivation, etc.

One issue is people can get brain damage or dimentia and lose their ability to learn new things while still retaining what they've already learned in their pre-morbid state. In these cases, crystallized tests are like fossils crystallized in rocks, preserving the intelligence that once existed, long after it's gone.

chartreuse1737 said...

"the ability to learn" is another mere abstraction. one can speak concepts into existence. he cannot speak things into existence. and things needn't conform to concepts.

and putative "fluid" tests do NOT measure learning ability even if there were such a thing.

as one professor of mine said, "for most students school is just pattern recognition. they 'learn' what they have to to pass and then they forget it."

it's been my experience that there are humans who correspond to airdales. that is, they do not learn quickly, but they do learn forever. they do not learn to shuck and jive like a pigeon in a skinner box. they understand.

iq and speed of learning are very decidedly NOT the same thing. metaphorically, human airdales will have higher iqs than the pattern recognizers.

Simon Waters said...

Comes up in teaching kids chess. Whilst some young kids really "get chess" at a very young age, the majority struggle with basics till they are around 9. Thus being bright, but not an especially good chess player I'm about the level of the best 13 year olds in my country. Sure there is a lot of learning in chess, but the best 16 year olds are way ahead of me, and it ain't three years extra learning, heck one guy was beating me at 18 who learnt at 16.

Simon Waters said...

I think as parents we have a duty to do the best for our offspring, part of that is selecting partner. Genetic fixes, and similar, fit in the same way. I vaccinate to avoid disease in my child for the same reasons. My concern is not the need to do this, but when is it safe/effective. We already see that with the cervical cancer vaccine, which is fantastic science, and safety is excellent, evidence of effectiveness from antibody response excellent, but the evidence for benefit is just (literally Dec 2013), and that benefit is a reduction in HPV 16 and 18 in women under 24. It was introduced 5 years ago. I'm sure in time we'll see a 65% or more drop in cervical cancer, but there are assumptions built into that claim which could be wrong, because disease epidemiology is complex. It could be the vaccine prevents harmless forms of HPV spreading which would have induced natural immunity. The risk of such is exceedingly low, otherwise we wouldn't be offering a universal (in girls) vaccine. Ultimately till the first generation die, hopefully at more than average life expectancy, we won't be able to be completely confident. This case is a no-brainer, but not all interventions bringing short term advantage are as clear cut. I can imagine my son being presented with 10 or 20 genetic treatments for his offspring, all in varying stages of evidence, none of which will have had long term testing. As with vaccine there will be nay sayers for whom no evidence is not sufficient, but part of our confidence with vaccines is we have a couple of centuries of experience.

Leftist_Conservative said...

I find this entire column and comment thread insensitive and offensive.
I myself am a caveman, a neanderthal, if you will. I was discovered in glacier, frozen, some years and thawed out and brought back to life.

My IQ is not so low that I could not make it in this frightening and confusing modern world. In fact, I even made it through college and law school.

Anon said...

I think people need to not be so afraid of scientific advancement. If we can better ourselves through science, we should. Certainly not force it on anyone, although I can't imagine anyone not wanting the best for their children. If you could make you children smarter, healthy, stronger, kinder,happier, better why wouldn't you? I think anything negative that impacts a person and society, if we have the capability to over come it through science, we should offer it! It reminds me of the recent movie, transcendence. This guy uploads his mind into a super computer and then he is able to come up with all of these wonderful ways to heal the earth and better people physically. However, because people were too afraid of the advancements, as they came much more quickly than people could understand what was behind it, they were too scared to see what the computer was trying to do and offer. People have always been afraid of advancement and technology and science. It's sad really.

I don't think we should bring back long extinct things like mammoths and neanderthals. I think they belong in the past. However, if we can use that same technology to save recently extinct animals who died because of our behavior or save animals who are endangered for the same reason, then absolutely I think we should. I think to bring a neanderthal into this world as it is now would be cruel. They aren't quite human but not quite 'animalistic'. Yet they require the same basic necessities as us and we are over populated as it is, can't take care of our own species as it is. If we brought them back, we'd be responsible for them. We'd need to find land for them, house them, clothe them, feed them, educate them. For what? So they can be outcasts and barely understand what the hell is going on? They'd be miserable and they'd just be a drain on our society. And if we're going to advance their brains to be like ours... then what's the point? We'd have human brains inside neanderthals bodies. Extra cruel!

I'd be okay with maybe a family of them in a special institutional environment for study purposes, as long as they were well taken care of, as long as they were sterilized and couldn't breed. To see what their behaviors and habits were I think would be fascinating. However, not to where there's a whole bunch of the wondering around and breeding and interbreeding and needing all kinds of things and taking up a bunch of resources and having to try to fit in but of course can't. No matter what, they'd never be human. We could be as kind as possible to them and except them with love and openness, but they'd never be human... yet they'd have to live in our world. Caught somewhere in between human and lower animals. >.< Horrifying.... and they'd never understand why.

Darryl Koala Jones said...

what if their characters were way more advanced, could we come up with a genetic modification for that?

Oliver Clozov said...

This guys view of neandertals is pathetic.

William Hayes said...

Where did you come up with the idea that Neanderthals were stupid? They created tools, buried their dead, and did a lot of things that homo sapiens were doing at the time. Are they stupid because they went extinct? Well in that case, if nuclear bombs started to go off like some apocalyptic movie scenario or an asteroid hit Earth, cockroaches would survive and humans would die. Would that make cockroaches smarter than humans?

Dmitry Postrelov said...

There is a general problem for cloning any ancient
organisms: mammoths, Neanderthals and even ancient Homo Sapienses.

The matter is that the arm race between big organisms like
us and different pathogens is a part of evolution. We are under natural selection
all of the time and genomes of our species are changing in order to resist a
new pathogens.

Like nowadays Homo Sapiens is passing natural selection for
carrying genes that provide HIV resistance.

So, if you clone an organism that lived 50-100 thousands
years ago – its genome would miss adaptations to all new pathogens that emerged
since its death. Thus, it can die of something that can barely cause us rheum
or even cause nothing. Does not really matter if you clone an extinct organism
like Neanderthal or his Homo Sapiens contemporary, they both would not fit our
harsh reality.

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