Commenter MeLo asked about the IQs of dolphins.  According to Wikipedia, the tucuxi dolphin have an encephalization quotient of 4.56, meaning their brains are 4.56 times bigger than the statistically expected brain size for an animal their size (not to be confused with simple brain size/body size ratio which is a less accurate measure of intelligence).

The EQ of dolphins is larger than that of chimps (2.4) and they have IQs around 35, but smaller than that of Homo erectus (6.0), who likely had an IQ around 55.  This suggests an IQ around 45.

To put these numbers in perspective, modern humans have an EQ of 7.61 (far and away the highest in the history of the World, if not the galaxy, and in some countries, our average IQ exceeds 100).

But the fact than IQ as high as perhaps 45 could have evolved independently in a lineage so divergent from humans is strong evidence that evolution is progressive and that intelligence is the ultimate adaptation: an ability to adapt itself.

And indeed, few animals have had to adapt as much cetaceans whose ancestors first adapted to the oceans, then evolved into successful land animals, only to have readapt to ocean life.  Few organisms have travelled such a transformative evolutionary path, making dolphins especially evolved, adaptable and intelligent.

Because evolution is so incredibly progressive, I predict that if humans go extinct, and the earth remains intact, within 10 million years there will be another species, at least as intelligent as we are.  It seems dolphins have already made it up to IQ 45 and chimps and even crows are not far behind; it’s only a matter of time before one of their descendants hit 100.

Because evolution is progressive and intelligence is perhaps the ultimate adaptation.

A while ago I took IQ and brain size data mostly reported by Richard Lynn and attempted to correct it to show the IQs and brain sizes the races would have if they all enjoyed First World 21st century living standards.  I called these corrected values, genetic IQ and genetic brain size, though in fairness, many actual anthropologists would call it pseudoscience.

The problem was that the IQs Lynn reported for Bushmen, Pygmies and Australoids were so incredibly low (even after correcting for their low human development index) that I was left with a very steep slope for predicting a population’s genetic IQ from its genetic  brain size.  The absurdity of this steep slope became apparent when I tried to extrapolate the trend beyond humans and predict the IQ of chimps from their cranial capacity (about 498 cc if adjusted for their small size), and got an estimated IQ below zero!

I decided that the problem was that Lynn’s IQ data for Australoids, Bushmen and pygmies simply isn’t credible.  You can’t give conventional IQ tests to people still living in hunter-gatherer societies and expect to get good results and there’s no credible evidence that any extant human race or ethnicity has a genetic IQ below the 80s. So after removing these three outliers, we get the following line of best fit predicting population IQ from population brain size.

Now when we predict the IQs of chimps from their cranial capacity we get 26, which is within 10 points of actual laboratory research suggesting an IQ of 35.

[Update January 1, 2017: An earlier version of this article included an estimate for anatomically modern humans that has since been removed]

[Second update January 1, 2017: An earlier version of this article underestimated the IQs of Australoids]

[Third update January 1, 2017: An earlier version of this article underestimated the IQs of H. erectus and chimps]

[Fourth update January 1, 2017: An earlier version of this article overestimated the IQs of Australoids]

[Fifth update Jan 3, 2017: Australoids, Capoids, Pygmies, and Neanderthals have all been removed because of lack of quality evidence]

[Sixth update Jan 17, 2017: Homo erectus and chimpanzees removed because of technical questions]

Below is a rough ranking of 16 different populations by estimated genetic IQ.  I should note that many scientists consider all human races to have equal genetic intelligence, and the below numbers would be considered pseudoscience.  All IQs have been rounded to the nearest multiple of 5 for aesthetic purposes.

Ashkenazim Genetic IQ 110

East Asians Genetic IQ 105

Whites Genetic IQ 100

Arctic people Genetic IQ 95

Southeast Asians Genetic IQ 95

Native Americans Genetic IQ 90

Pacific Islanders Genetic IQ 90

Dark Caucasoids Genetic IQ 90

Congoids Genetic IQ 85

According to wordpress statistics, when I founded this blog in 2014, about 9,773 unique visitors stopped by sometime during the year.  At the time I wasn’t famous, so the fact that nearly 10,000 people a year were already reading my blog was a huge thrill!

Then in 2015 the unthinkable happened. A mind blogging 140,844 people read my blog!  Well, I’ve peaked I thought.  It’s all downhill from here.

Then in 2016 a STRATOSPHERIC 334,202 people read my blog.

I’d like to thank each and every one of you!

Happy New Year!

Based on the fact that they left behind no drawings, I now estimate Neanderthals, like Homo erectus, had an artistic IQ of about 26.  However in the documentary Apocalypse Neanderthal, a scientist mentions that it took him a year and a half to learn to make the stone tools Neanderthals made all the time.  Since scientists probably average about 125 IQ, that might suggest Neanderthals had a spatial IQ as high as 125!

Assuming about a 0.35 correlation between artistic IQ and technological IQ, we might very crudely estimate an overall IQ of 71 for Neanderthals.  I realize this is all very speculative, but scientist Steve Hsu arrived at a similar figure, stating:

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.

Hsu doesn’t explain why he estimates an IQ of 70, but notice how he cites the fact that genetically  Neanderthals were twice as different from modern humans as modern humans are from one another, so perhaps he’s simply doubling the IQ standard deviation of 15 to guess that Neanderthals were 30 points below IQ 100 (defined as average on IQ tests).

An average IQ of 70 appears to be the threshold for discovering agriculture, something Neanderthals failed to do even during the Eemian, when they had 15,000 years of warm climate to do so.  Anatomically modern humans also failed to make the leap to agriculture during those same 15,000 years, suggesting no modern human population had an average IQ above 70 before the upper Paleolithic, around the time scholar Richard G Klein believes a massive brain mutation occurred causing behavioral modernity.

What kind of genetic change might have occurred?  Hsu once mentioned that a high quality Neanderthal genome had a genetic variant associated with developmental delay and autism.  Perhaps prior to behavioral modernity, modern humans also had this variant in large numbers?

According to scholar Richard G. Klein, if you took someone from Africa 80,000 years ago and dressed them up in modern clothes and had them walk into a university lecture hall, the only thing we would notice is that the person was extraordinarily well built (see 10:50 in video below):

But behind the normal appearance would lurk an incredibly primitive mind.  For according to Klein, before about 50,000 years, the freak mutation causing behavioral modernity had not yet occurred, even though anatomical modernity evolved 200,000 years ago.

According to Klein all peoples today are behaviorally modern.  That means that if HBD is correct, and Bushmen and pygmies have genetic IQs no higher than 70, then the Africans before 50,000 years ago must have been lower still.

How much lower?

In my last post, I estimated that homo erectus, who lived from 1.9 million years ago to 70,000 years ago, had an average IQ of 29.  Meanwhile anatomically modern humans appeared 200,000 years ago.

According to geneticist Spencer Wells, from 1 million years ago, to 65,000 years, there was virtually no cultural or technological progress, so big brained anatomically modern humans were still behaving like IQ 29 Homo erectus for 135,000 years!

What were the IQs of these people?  They must have been much smarter than tiny brained Homo erectus (IQ 29) but not as high as today’s Bushmen and pygmies (genetic IQ at least 70) who have made the leap to behavioral modernity. Let’s split the difference and assume they had an IQ of 50.

So for 135,000 years, Africa was inhabited by IQ 50 people who looked just like modern big brained Africans, yet were behaving like tiny brained Erectus, making the same simple one million year-old stone tools over and over again like mindless zombies for 135,000 years, until finally a genetic mutation snapped them out of their trance, and made them behaviorally modern.

It must have been an incredibly terrifying time if we could see it, because everyone would have looked like fully modern black Africans, yet would have had the mind of animals.

I should be sleeping because I have a long day at work tomorrow and a huge weekend of drunken partying, but I am so excited about this post that I must write it right now.

I’ve posted about the IQ of Homo Erectus before, but in this post, I will refine my analysis in light of better understanding.

Technological IQ 55

Experiments suggest that it’s not until a child is seven that she has the mental capacity to create the kind of stone tools Homo erectus created. In other words, Homo erectus may have had the intelligence of a Western seven-year-old. On the WISC-R IQ test, an incipient adult (age 16.9) who performs like a seven-year-old on the spatial construction subtest scores lower than 99.5% of biologically normal members of his generation. In other words, an IQ of about 60.

But we should keep in mind that the research on seven-year-old tool making ability was published in 1979. Probably because of better nutrition/health,truly culture reduced spatial skill has been improved by about 0.2 points a year until 2006 (when U.S. nutrition gains seem to have ended). So Homo erectus probably had an IQ around 55 on the most recent culture reduced Western norms (U.S. white norms).

Draw a man IQ 6

In 1.9 million years, H erectus was too stupid to draw anything, let alone a man, so on the on the Draw a Man IQ test he would have scored a bit fat goose egg: zero.

What IQ does zero equate to?

On the Goodenough-Harris Draw-A-Man test, the mean and standard deviation for U.S. 15-year-olds (considered adult level for the purpose of this test) is 46.3 and 9.1 respectively, so zero equates to an IQ of 24 (U.S. norms) or 19 (U.S. white norms).  But because these norms were published in 1963, and norms on this test became inflated at a rate of 3 IQ points per decade (Lynn, 2006) until at least 2006, we must reduce this IQ to 6 on modern white norms.

Correcting for culture bias, Draw-A-Man test suggests an IQ of 26

Because even the Draw-a-man test is culturally biased, we must do our best to adjust for the stone age environment H erectus lived in.  It’s well known that on typical IQ tests, dropping out of school causes IQ scores (though perhaps not real intelligence) to drop by 2 points per missed year, and research on adopted kids shows that each extra year of education in the rearing parent raises a child’s IQ score by 1.17 points.  Although such cultural biases fade by adulthood, as scholars Dickens and Flynn brilliantly noted, this is only true within generations.  Between generations these environmental effects are permanent.

So considering the average H erectus had about 13 years less schooling than today’s average white, this would artificially depress his IQ by 26 points.  Further, being raised by parents with 12 less years schooling than today’s average white would artificially depress his IQ by another 14 points. So these two cultural biases together should artificially depress his IQ by 40 points on a typical IQ test, but because the Draw-A-Man test is only about half as culturally biased as a typical IQ test, we’ll say it’s depressed by only 20 points.

You might ask, why, if the Draw-A-Man test is only half as culturally biased as a typical IQ test, does it show the full 3 point a decade Flynn effect.  The answer is because the Flynn effect is not entirely cultural, it’s also biological (nutrition) and Performance IQ tests like Draw-a-man are sensitive to nutrition (which H. erectus had plenty of).

So adding 20 IQ points to their IQ of 6, to compensate for the test’s cultural bias, raises them to IQ 26.

I realize such corrections are very simplistic, but it seems to give believable results.

Overall IQ

Assuming a technological IQ of 55 and an artistic IQ of 26, and assuming only a 0.35 correlation between the two, Homo erectus had an overall IQ of 29!

Brain size of Homo erectus

According to Wikipedia:

H. erectus fossils show a cranial capacity greater than that of Homo habilis (although the Dmanisi specimens have distinctively small crania): the earliest fossils show a cranial capacity of 850 cm³, while later Javan specimens measure up to 1100 cm³,^[48] overlapping that of H. sapiens

The below chart shows a line of best fit for the average genetic brain size and the average genetic IQ for contemporary human races (based on controversial estimates many would consider pseudoscience).

If we extend the trend line to extinct Homo species like Erectus, and if we assume Erectus reached their genetic potential for brain size and IQ (early hunter/gatherers living their natural life style seemed to have far better nutrition than all but the most  recent First World agriculturalists and Erectus eventually learned to cook its food, digesting even more nutrients) then we can estimate from their brain size that they had an IQ of about 5 when they first appeared, and 40 by the time they went extinct. Averaging the two estimates, gives an IQ of about 23, not that different from the 29 we got based on a historiometric analysis of their technological and artistic talent.

Chimpanzees have a cranial capacity of about 400 cc, and a mean body weight of about 45 kg.  If they weighed as much as a human in optimum physical shape, they’d be expected to have a cranial capacity of 498 cc.

Below is a chart showing the estimated average genetic IQ (i.e. the IQ they would have in First World middle class environments) of many human races, as a function of their average genetic brain size:

It is interesting to ask whether we can predict chimp IQ by extrapolating from human racial differences.  When we enter the chimp brain size of 498 as X into the line of best fit, it predicts an IQ of only -46!

Could chimps really be that stupid?

Research suggests that on most cognitive tasks, chimps are at about the level of a Western 2.5-year-old, which equates to a deviation IQ of about 40 (U.S. white norms): 4 SD below the U.S. white mean.

On the Wechsler scales, if you average 4 SD below the mean on all subtests, your full-scale IQ is 5.71 SD below the mean, equating to an IQ of only 14.

So chimps probably have an IQ of perhaps as low as 14, which is 60 points higher than predicted from the population level correlation between IQ and brain size in humans.

The fact that human racial differences on the brain size-IQ dimensions does such a poor job predicting the IQ of our closest living relative, suggests there might be something very wrong with HBD data.

The above chart has six columns.  In the first column I list 13 human races.  In the second column I list the IQs assigned to each of these 13 races by scholar Richard Lynn, on a scale where the British white mean is set at 100 (SD = 15).  In the third column I list the “real IQ” of each of these races.  That is, the IQ score each would get on a tuly culture reduced test, not the pseudo culture reduced tests they were often given like the Raven Progressive Matrices.  Real IQs were estimated by averaging the reported IQs in column 2, with the genetic IQ is column 4.

Genetic IQ

The genetic IQs in column 4 were estimated by noting that black Americans score about 85 on IQ tests as adults (even when reared by upper class whites) yet black Africans score 67, even though the two groups should have the same genetic IQ.  Yes black Americans have some white admixture which should have raised their genetic IQ above black Africans’, but they are also descended from perhaps the least intelligent class of black Africans (slaves) which should lower their genetic IQ below the average black Africans’, so on balance they should have the same genetic IQ.

And yet black African school kids score 18 points lower than African Americans, suggesting the poverty, illiterate parents,  malnutrition and disease of sub-Saharan Africa is  holding them back.  Averaging the 2001 human development index (HDI) of Cameroon and Cote D’Ivoire together (see table 7 of this paper), I estimated that sub-Sahara had a 2001 HDI of 0.448, compared to 0.937 for the United States and this roughly explained why they scored 18 points lower than U.S. blacks. From here I came up with the following formula:

Genetic IQ = Reported IQ + [(0.937 – population HDI)/0.02716]

For races that live in economically advanced countries such as Ashkenazim, East Asians, and Whites, IQs were assumed to equal genetic IQ, but for races like Southeast Asians and Pacific Islanders, I estimated the 2001 HDI of the Southeast Asia region to be 0.751 (based on the Philippines) and the above formula was applied.  Similarly, for Dark Caucasoids, I assumed the Middle East had an HDI of 0.709 (the average of Saudi Arabia and Egypt).

Although Arctic Peoples, Native Americans, and Austalian aboriginals technically live in developed countries, they are often segredated on reservations, and have HDIs below their fellow citizens.  Arctic Peoples were assigned an HDI of 0.851 based on the reported value for Canadian indigenous peoples (again see table 7 of this paper).  Native Americans were assigned an HDI of 0.864 based on averaging the HDI of Canadian and U.S. indigenous peoples.  Australian aboriginals reportedly had an HDI of 0.724.

Capoids and Pygmies were assumed to have the same HDI as mainstream black Africans (Congoids).  Although this is probably false, the Capoids and Pygmies used in actual IQ studies were those who lived side by side with their Congoid cousins under illiterate conditions.  Their actual IQ scores were probably a lot lower than the 54 Lynn reported for them, but because they scored about 13 points lower than illiterate Congoids, and Congoid school kids scored 67, it was assumed that Capoid and Pygmy school kids would score 67 – 13 = 54 if they too were in school.  Since the IQ was calculated under the scenario of similar environments, the genetic IQ was calculated assuming the same HDI.

Brain Size

Row 5 gives brain sizes reported by Lynn with the exception of pygmies which was reported by scolars C.L. Smith and K.L. Beals.  However since Lynn cited Smith and Beals as his brain size source, the figure should fit right in.

Row 6 gives estimated genetic brain size for each of the 13 races.  Because craniometry became taboo after WWII, I assume most of the brain size data was obtained before the 1930s, and perhaps well before the 20th century.  However Lynn notes that in the 1930s, people in the developed World began growing taller because of better health/nutrition and that height gains were perfectly paralleled by brain size gains.  Since height among U.S. whites has increased by 1.3 Standard Deviations over the 20th century before plateauing in 2006, I assumed that prior to the 1930s, Whites, and by extension every other race, were also 1.3 SD below their genetic brain size, and so genetic brain size was estimated by adding 118 cc to the Smith and Beals numbers.

To my knowledge Smith and Beals did not give data on Ashkenazim brain size, but very old studies suggest they were 30 cc below the white mean, so their genetic brain size is assumed to also be 30 cc below the genetic white mean.  These old studies give very different white brain sizes from Smith and Beals, showing how sensitive cranial capacity measures are to methodology.

I calculated the line of best fit to estimate the genetic IQ of a population from its genetic brain size, where X is genetic brain size (genetic cranial capacity) and Y is genetic IQ.  Pygmies were excluded because their small bodies make their brains abnormally small, even relative to IQ:

The more I think about the upper paleolithic revolution, also known as the mind’s big bang, the great leap forward, or behavioral modernity, the more I think it fits perfectly with Richard Lynn’s theory that exposure to the ice age caused high IQ to evolve.

The upper paleolithic revolution (UPR) refers to a sudden explosion in culture that occurred in the archeological record around 50,000 years ago.  According to scholar Richard Klein, it was caused by a brain mutation that occurred in East Africa 50,000 years ago that allowed humans either the intelligence or language to leave  Africa and conquer the World.  The only problem with Klein’s theory is no such 50,000 year old mutation has yet been discovered, and most scientists seem to think humans left Africa 70,000 years ago, and most of the evidence for this great leap forward seems to come from Europe, not Africa.

For example here’s a fascinating list of the 10 oldest works of art ever discovered.  Notice how anything older than 50,000 years ago does not really qualify as art.  Only after 50,000 years ago do we get real art, and notice how all the oldest real art was found in Europe.

I think what probably happened is that anatomically modern humans evolved in Africa about 200,000 years ago, and probably had a mean IQ of 72 (genetically and phenotypically).  Then about 70,000 years they left Africa, and were exposed to the challenges of building watertight shelters with strong insulation and animal skin walls,  learning to make fire, creating warm clothes and mastering the complex art of sewing, and figuring how to hunt large animals since plants were not around.  The low IQ people, and low IQ tribes could not adapt to these challenges, leaving higher IQ people as the survivors.

So by about 39,000 years ago, the IQs of the proto-Caucasoids in Europe had finally reached the 80s, and they had discovered not only the art of drawing, but had the spatial ability to draw realistic forms despite having never been exposed to art, and by 38,000 years ago, were making impressive sculptures.

Alternative theory

Another theory, popularized by Greg Cochran and Henry Harpending in the book The 10,000 year explosion is that this cultural revolution was caused by gene flow from Neanderthals, which somehow dramatically improved the cognition of modern humans.

One problem with this theory is that Neanderthals went extinct partly because they LACKED these abilities, so it’s ironic to suggest they gave them to us.  Of course it’s always possible that the unique COMBINATION of human and Neanderthal brain genes produced an intellect far greater than either species on its own, but why entertain such a speculative idea when there’s a much simpler explanation that has repeatedly proved useful in the field of HBD: cold winters select for higher IQ.