It is almost unanimously agreed that human intelligence grew since the Upper Paleolithic until the industrial revolution. The supporters of this idea rely their demonstration, first of all, on the fact that higher class people were more fertile and also more intelligent than lower classes. Secondly, they rely on the human genome being stable, on the reduced rate of new mutations in each generation, and they also regard the selection pressure on intelligence as sufficiently high to positively select favorable mutations and efficiently eliminate the unfavorable ones.
A set of data, some known for a while already, some discovered relatively recently, seriously doubt the theory stating that human intelligence had been rising continuously, on the other hand supporting Robert Klark Graham’s theory from 1970 according to which intelligence reached an apogee in Aurignacian, with the first human considered to be modern, and then it diminished continuously. In brief, contemporary people who are less different genetically from the Cro-Magnon Man, and who renounced his lifestyle later, are more intelligent than those who genetically differ more and whose lifestyle changed earlier from the northern Eurasian hunter of the Upper Paleolithic. This more logically explains not an increase but rather a decline of intelligence during the last 35,000 years.
Reductio ad absurdum
Suppose that human intelligence would have grown since 35,000 years ago, when the caves of Chauvet and Coliboaia were painted, the Lion Man of Hohlenstein statue was carved, as well as Venus from Hohle Fels, the Ivory Mammoth carving from Vogelherd, and the oldest flute known so far, from Hohle Fels, made from an eagle bone. Suppose that the ancestors of nowadays Western European populations increased in intelligence in the last 35,000 years with an average of 1 IQ point per millennium, equating 1 IQ point every 30-40 generations. Suppose that such an increase took place up to 75 years ago, when the Lynn-Flynn effect, who generated an increase of 10 IQ points with each generation, started.
In the western part of Europe more than two thirds of males carry the y-DNA haplogroups I1, R1a, R1b, N1c1 (Batini, 2015), which nowadays positively correlate with intelligence (Cretan, 2011; Rindermann, 2012). Therefore, in other parts of Western Eurasia, intelligence should have grown with less than 1 IQ point per millennium, due to continuing natural selection in this 35,000 years period.
The average IQ of Western Europe 75 years ago, measured by 2016 tests, should have been around 75 points, close to the mental retardation threshold of 70 points. Given the supposed growth of only 1 IQ point per millennium, the man from Upper Paleolithic should have had, 35,000 years ago, an average IQ of 40 points, meaning that the entire population was below mental retardation threshold, and half of it was below the severe mental retard limit, although back then brain volume was 15% larger compared to nowadays.
However, if we accepted the fact that during the last 35,000 years, due to relaxing natural selection pressure, intelligence declined with only 1 IQ point per millennium, this meant the Aurignacian man would have had an IQ of 110 points, measured by current tests. Should the intelligence have dropped by 2 IQ points per millennium, the hunter living 35,000 ago would have had an IQ of 145. It seems more natural to accept that Cro-Magnon had an average IQ of 110 or 145 rather than 40, considering that he managed the revolutionary jump from archaic to modern man (Bar-Yosef, 2002).
Cro-Magnons and Inuits
I shall compare the Cro-Magnon with the Inuit populations from the past few centuries.
In respect to technological innovation, we can say that the Cro-Magnon was superior to the Inuit. The Inuit living a few centuries ago did not have any weapons or tools unknown to the Cro-Magnon. The difference is that the Inuit has inherited them, whereas the Cro-Magnon has invented them. Another difference is that we have access to the entire technology used by the Inuit, whereas we only know a part of the Cro-Magnon’s. As such, any new discovery may very well tip the scales in favour of the Palaeolithic hunter. As technical innovation requires firstly and foremost high spatial intelligence and as the Inuit possess this type of intelligence to a very high degree among current populations (Lynn, 2010), we can draw the conclusion that Cro-Magnons too possessed it to a very high degree. Otherwise, Cro-Magnons had live also, 45,000 years ago, in Siberan Arctic, at only 2,000 km distance of the North Pole (Pitulko, 2016).
Concerning artistic intelligence, it seems that in this area too the Cro-Magnon is superior. Cro-Magnons too have performed sculptures similar to those of Arctic hunters but they have also excelled in cave paintings.
Regarding verbal intelligence, it is very likely that it was higher in the case of the Cro-Magnon, as a Palaeolithic group had more members than an Inuit family; in addition, the surrounding environment was more varied. Thus, both elements required greater verbal performances. It is likely that verbal intelligence was subject to a higher pressure of selection in the case of the Palaeolithic hunter, and hence superior to the Inuit’s.
As the Cro-Magnon group had more members, an alpha male had access to more females than an Inuit, which increased natural selection, thus giving rise to better conditions for increasing or maintaining the average level of intelligence of a population.
Everything seems to point towards the fact that the Cro-Magnon was more intelligent than the Inuit – on all levels.
As for Canadian Inuit, my opinion is that they form one of the populations whose genotypic intelligence has decreased the most as a consequence of the Industrial Revolution. Here are my arguments. If in 1867 the Inuit population in Canada was estimated at around 2000 members, the same population is today 30 times as numerous (The Canadian Encyclopedia). The multiplication process has been even more significant, as we are not taking into consideration here the members who have crossbred. This is a growth rate which points towards an extraordinary weakening of natural selection, which could only lead to an important decrease in genotypic intelligence throughout the last 150 years. Aside from the population growth rate, contact with the infectious pathology of the White population, as well as their diet and alcohol may have played a significant part in the Inuit population’s decrease in intelligence. We may assume that, by living in a developed country – Canada – the Inuit have benefited from a significant increase in phenotypic intelligence, through the Flynn effect. But all statistics indicate that the Inuit do not enjoy the average Canadian standard of living; as such, the Lynn-Flynn effect is perhaps lower for the Inuit than the Canadian average. Moreover, the Inuit have not ‚invested’ into modern comfort as much as the others; instead they have ‚chosen’ to invest into a higher growth rate for their population. In contrast, the Lynn-Flynn effect is more apparent in populations with a low or even negative population growth rate. All these arguments point to the fact that Inuit before the Industrial Revolution must have had a significantly higher level of intelligence than today’s Inuit population. We should not exclude the possibility of the Inuit having been the most intelligent population in the world immediately after the Industrial Revolution, but also having been the great losers of this Revolution in terms of intelligence. Precisely because they have been the great winners in terms of population growth.
Based on reaction time, which is considerd a highly qualitative measure of genotypic intelligence, one meta-analysis revealed that Victorian age Europeans had an IQ 14 points greater than their contemporary descendants (Woodley, 2013), in spite of current Europeans having a higher fenotypic IQ due to the Lynn-Flynn effect.
Maintaining the assumption that genotypic intelligence had grown in the last 35.000 years by 1 IQ point per millennium, the paleolithic hunter should have had a much longer reaction time, in accordance with an assumed IQ 35 points lower than his descendant, the Victorian age Englishman.
We will never be able to measure paleolithic man’s IQ through tests, nor his reaction time. However, the opposite hypothesis appears more plausible to me: the Aurignacian hunter’s reaction time, a crucial parameter for his survival, was shorter than modern British man’s, while having a corresponding higher genotypic IQ.
Besides, two of the studies which Woodley included in his meta-analysis reveal that Finns from the end of XXth century had a reaction time as short as British people and Americans from the end of the XIXth century. As in the case of English people, the reaction time of the Finns probably has grown during the XXth century, and one century ago it was shorter than the reaction time of their contemporary British. For the most logical explanation, the Finns always had a shorter reaction time, because their ancestors remained hunters for longer than the ancestors of British people. Besides, northern people from nowadays are genetically closer to the Paleolithic northern hunter than any other Europeans (Fu, 2014). Therefore, they preserved his intelligence the most, as revealed by a shorter reaction time.
More logically, the Paleolithic northern man had a higher genotypic intelligence than nowadays people, who lost part of this intelligence proportionally to their genetic divergence from this man, rather than current people being more intelligent than the Upper Paleolithic hunter while at the same time the most intelligent from nowadays are those who genetically differ less from him.
Studies of the genome
A genetic study, comparing the presence of rare functional alleles in people with a very high IQ (a group of 1,400 humans having an IQ greater than 170) versus people with normal intelligence (a control group of over 3,000 individuals), conducted on Americans declaring themselves whites, found significantly less rare functional alleles in very intelligent people (Spain, 2015). Another study states that most (81.4%) of the rare alleles found in Americans with European origins appeared in the last 5,000 to 10,000 years (Fu, 2013).
From these two studies it results the European paleolithic man is genetically closer to nowadays individuals with a very high IQ than it is to individuals with a normal intelligence, since the paleolithic man couldn’t have alleles which apeared after the beginning of the Neolithic. Taking into account the smaller number of rare functional alleles in his genome, it is more logical that the paleolithic man was cleverer than the average man from current times. The same logic implies that intelligence drops at least since the Neolithic.
The fact that humans with a very high intelligence have significantly less rare functional alleles in their genome confirms the hypothesis of one study stating that the accumulation of the rare alleles led to decreases in intelligence, at least for the last 3,000 years (Crabtree, 2013).
Also, the genome of a human having lived 45,000 years ago in western Siberia, who belonged to the Eurasian population from before the separation of the West-Eurasian and the East-Eurasian branches, shows that he is genetically closer to East-Asians than he is to Europeans and West-Asians (Seguin-Orlando, 2014). Another genome, of a human having lived 37,000 years ago 500 kilometers south of Moscow, who belonged to the West-Eurasian branch (after the separation from the East-Eurasian branch), reveals that, from all current Europeans, the closest genetically to him ar those from the North (Fu, 2014). It can be noted that paleolithic northern men are closer genetically to current more intelligent populations and farther from those with a lower IQ.
Studies on y-DNA haplogroups as markers of intelligence
Comparing maps of y-DNA haplogroups in Europe with IQ maps led to the conclusion that I1, N1c1, R1a and R1b haplogroups are positively correlated with intelligence (Creţan, 2011; Rindermann, 2012). All these haplogroups share the fact that their carriers moved to a sedentary life and agriculture later than the carriers of the other haplogroups which exist nowadays in Europe: I1 and N1c1 remained hunters for a long time, and Indoeuropeans R1a and R1b were shepherds and then became the conquering warriors from Bronze Age and later on. It appears logical to think that adopting a sedentary life and agriculture weakens the selection pressure on intelligence and leads to it’s decline, since haplogroups which entered the Neolithic faster are negatively correlated with intelligence.
Besides, having entered Europe just 5,000 years ago, the carriers of haplogroups R1b, I1 and R1a are the ancestors of two thirds of the current inhabitants of the continent, therefore proving to have been more competitive than their rivals who carried some Neolithic haplogroups (Batini, 2015). In another part of the world, the high intelligence of current Koreans and Japanese can be explained as well by a late adoption of agriculture (Creţan, 2011).
Studies on brain volume
Intuitively, there should be a link between brain volume and intelligence. Most of the studies indeed found different correlations of cerebral dimensions and IQ. One wider meta-analysis, based on measurements made in vivo, found a 0.33 correlation between brain volume and IQ, greater in females and in adults (Mc Daniel, 2005). A more recent meta-analysis reveals a correlation of 0.24 (Pietschnig, 2015). But another recent study found that the genetic correlation between educational attainment and intracranial volume is 0.44 (Hagenaars, 2016).
Being a very characteristic process for anthropogenesis, the growth of brain size stopped in Pleistocene and reversed in Holocene. A study of the evolution of cranial capacity in Europe, Western Asia and North Africa from the Upper Paleolithic until present day found a slight initial increase, reaching a peak in Mesolithic, for both males (1593 cc) and females (1502 cc), and then an important decrease reaching the minimum in present day (1436 cc in males and 1241 cc in females). The decrease represents a 9.9% drop in size for males (157 cc) and 17.4% for females (261 cc) (Henneberg, 1988). The same trend of continuous decrease, but smaller, was recorded for the same period in Sub-Saharan Africa (Henneberg, 1993). Another study found a maximum cranial capacity during Aurignacian and a minimum in the present day European human (Wiercinski, 1979).
A decrease of the encephalisation was recorded during the past 25,000 years (Ruff, 1997).
Taking into account the existence of a correlation, even if modest, between brain volume and intelligence, as well as the significant decrease of cerebral volume, it is much more probable that in this period intelligence also decreased, rather than it increased. Even a phenotype-only increase of intelligence, as resulted from the Lynn-Flynn effect, is accompanied by an increase in brain mass (Woodley, 2016).
Moreover, research on population samples from USA and New Zealand which have European ancestry, focusing on the DUF1220 domain, have shown that increasing the number of CON1 and CON2 copies leads to an increase of cerebral volume, gray matter and number of neurons, the most powerful association being with the right frontal cortex for both CON1 and CON2. Meanwhile, there is a linear IQ increase according to the number of CON2 sub-type copies: for each additional copy, IQ increases by 3,3 points (Davis, 2015). Therefore, at least by the number of CON2 copies from the DUF1220 domain, a correlation between cerebral volume and IQ exists.
Studies regarding the brain volume and intelligence of wild and domestic animals
All domestic animals have a brain 5% to 30% smaller than their wild ancestors (Hemmer, 1990).
Southern wolves (the ancestors of dogs) have a 5-10% smaller brain than northern ones, Dingo dogs have a 25% smaller brain than northern wolves, primitive dogs from the Tropics and from Eastern Asia have a 15-20% smaller brain than the Dingo, European dog breeds have a cerebral volume intermediate between these primitive dogs and the Dingo, and it is likely the brain volume of Dingo Dogs increased after returning to wilderness (Hemmer, 1990).
In accordance with the larger cerebral volume, wolves are more intelligent than dogs (Frank, 1985; Udell, 2015). Dogs that quickly complete the detour tasks also tende to score highly on the choice tasks and this could be explained by a general intelligence factor (Arden, 2016).
Concerning wild animals, encephalisation predicts problem-solving ability in mammalian carnivores (Benson-Amram, 2016).
Also, brain size predicts, better than encephalisation quotient, cognitive ability across non-human primates (Deaner, 2007).
The reduction of selection pressure on intelligence for domestic animals resulted in the decrease of intelligence, in the same time with the decrease of brain volume. A similar phenomenon occured for the human: the actual man is just a domesticated Cro-Magnon, with a smaller brain, a lower encephalisation and a lower intelligence.
The cold winters of Wurm glaciation
The theory sustaining an increased pressure of selection imposed by cold winters during the Würm Ice Age explains the best an intelligence increase in the Paleolithic northern man, who lived in the temperate or subarctic Eurasian climate (Lynn, 1991; Lynn, 2006). However, the theory allows for comments and remarks.
This natural selection on intelligence acts mostly in the beginning, when the first generations, confronting the cold climate, are required to come up with strategies for adapting to the new environmental conditions. These strategies for adaptation were born since the beginning of Aurignacian, even though improvements and other inventions were also made during Gravettian, Solutrean and Magdalenian (the Aurignacian is an amazing revolution in the life of humans, the following periods of Upper Paleolithic being only developments, even the beautiful Paleolithic art exploded since Aurignacian). We must admit that, once the adaptation strategies were in place, the selection pressure on intelligence began to drop, since it is easier to follow a secure path, beaten by others, rather than opening a new road to unknown or even to nowhere.
We should admit that, once the glaciation ended, selection pressure relaxed even further. Population numbers did not increase considerably by the end of the glaciation while the inhabitable territory in Europe expanded, which excluded a fierce competition between human groups. A study on European population dynamic during the Upper Paleolithic estimates that, 30,000 years ago, the continent was inhabited by 330,000 humans. Then, 23,000 years in the past (halfway through the last glacial maximum: 26,000-19,000) the number dropped to 130,000. Later, 13,000 ago, the population rose again, reaching 410,000 humans (Tallavaara, 2015). The selection pressure most probably also knew an increase during the last glacial maximum, when the population dropped severely, along with the surface of inhabitable territory.
We should, also, admit a relaxation of selection pressure on intelligence in the neolithic period. A study of Neolithic demography (8,000-4,000) in Western Europe reveals an exponential growth of the population (Shennan, 2013). However, this growth occurred along the seizure of larger and larger territories by the neolithic agricultors and shepherds.
Distance from and closeness to Africa
There is a complementary theory for the cold winters hypothesis, and just as valid, stating the progressive increase of intelligence by distancing from Africa, as a result of adapting to novelty.
Entering a new territory implies an increased selection pressure on intelligence, especially for the first generations which must invent new survival strategies. After honing the strategies, such a population makes a return towards native Africa in terms of survival difficulty. Once the Eurasian Paleolithic hunter perfected hunting weaponry and technique, the hunt began resembling the foraging from tropical and equatorial Africa, moreover so if game was abundant. When the same hunter mastered fire and managed to make warm clothing and shelter, he made a return towards Africa. The same way, when glaciation ended and temperatures were on the rise, an equivalent of returning to Africa took place. When the farmer gathers the crops, he returns towards Africa. When we fill our carts in the supermarket, in some cases by money from social security and children allowances, we go even farther from returning to the abundant equatorial and tropical Africa. In all of these situations, selection pressure on intelligence drops, sometimes even below Africa’s level, in spite of living so far away from this native continent. In all of these situations, intelligence is allowed to decrease.
The Australian Aboriginals are geographically the farthest from Africa. Most probably they are also the most genetically distant from Africans. However, their migration represented in the end the greatest return to Africa, as their average IQ of 62 is the closest to the average IQ of 67 found in sub-Saharan Africa inhabitants (Lynn, 2010).
The later entrance to Neolithic
While the theories of cold winters and of distancing from Africa explain well the IQ differences between current populations through a faster and greater rise of intelligence during Paleolithic, the theory of later agriculture implementation explains mostly the differentiated intelligence decrease of different populations, until reaching the present day IQ. This theory is held valid by y-DNA haplogroups being markers of intelligence in Europe. Also, by superimposing a map of IQ in Eurasia over a map of Neolithic expansion, it can be noted that the first areas where Neolithic developed correspond to an IQ of 80, the intermediary areas of Neolithic expansion correspond to an IQ of 90, and the last areas to enter Neolithic have a current day IQ of 100. The same correlation exists between the expansion of Neolithic and character. It can be easily observed that populations with the strongest character were touched later by the expansion front of agriculture (Cretan, 2011).
Pressure of natural selection
Before engaging with those who assert that the decrease in intelligence has only started after the Industrial Revolution, I would like to set down a pre-requisite. When a certain pressure of selection is reached, the intelligence of a population stays constant. For any inferior pressure, intelligence will decrease; and for any superior pressure, intelligence will increase.
I shall take as reference the book ‘Dysgenics’ (1996) by Richard Lynn. It is a book that I agree with entirely regarding what has happened to humans after the Industrial Revolution. With respect to what has happened before, I hold different views.
I shall start by comparing two fragments from Richard Lynn’s book. The first fragment shows how natural selection functions (including sexual selection) for contemporary ‘pre-historic’ tribes: a leader has 2-3 wives and 9 children during his lifetime, 5% of all males have more than one wife, 62% of males have no children at all, 45% of children die before reaching adulthood. The second fragment is an illustration of the difference in fertility, of 50-100%, in favour of the middle class compared to the lower class in 16-17th century pre-industrial Europe.
Firstly, let us take notice of the fact that in the two cases there is a significant difference in terms of natural and sexual selection. There is a far greater pressure in ‘pre-historic’ tribes than in pre-industrial Europe. Let us assume now that in pre-industrial Europe, natural selection was sufficient to maintain a constant average intelligence because the more intelligent individuals had more offspring. In this case, the pressure in ‘pre-historic’ tribes, being higher, should lead to an explosive growth in intelligence from one generation to the next, something which has not been recorded. My opinion is that the existing selection in contemporary ‘pre-historic’ tribes can barely maintain a constant level of intelligence for these populations. And if these ‘pre-historic’ tribes can barely maintain a constant level of intelligence, then surely the pressure of selection in pre-industrial Europe was no longer sufficient to slow down the decrease in intelligence, even if the more intelligent had more offspring.
The theory according to which offspring should inherit, on average, the qualities of their parents is erroneous, as it does not take into account the occurrence of genetic mutations and the fact that most of these are not favourable. Human intelligence is a relatively recent human addition, so it is more fragile. Also, the number of genes involved in determining intelligence is probably high. Therefore, the likelihood of unfavourable mutations is also higher than of favourable mutations, which leads me to conclude that not all the offspring inherit their parents’ intelligence; that the average genotypic intelligence of the offspring is below that of the parents.
Another argument comes from the heredity of height. Humans from dominating classes were taller than humans from dominated classes (Newman, 2007) while also being more fertile than the latter. However, the average height of humans did not increase, but decreased in the last 35,000 years (Henneberg, 2006). Intelligence took the same path, having a very close heritability, of 0.71, to height, and whose correlation with height is 0.28 (Marioni, 2014). Another study found a heritability of 0.9 for height (Silventoinen, 2003).
Mutation rate and intellect fragility
The rate of single-base substitution mutations is estimated at 1.20 x 10-8 for each pair of bases, per generation, 85% of the mutations being paternal (Campbell, 2012). Taken together, insertion and deletion mutations are only approximately 6% as common as those involving single-base substitutions (Lynch, 2009). Furthermore, exons represent only 1% of the human genome and, from the total number of 20,000 genes, only 2,000 might be involved in cognitive abilities. The mutations affecting these 2,000 genes would represent 0,1% of the total number of mutations. However, unfavorable mutations are a small part of all the mutations, while favorable mutations are even scarcer. Research conducted so far also show that, in case of single-base substitutions, the effect of only one such mutation on intelligence is minimal and was found for just a few SNPs.
All this evidence suggests a great stability of the human genome, especially regarding those genes upon which intelligence depends. The probability of a significant decrease in the average intelligence of humans during the last 1,000 generations is very small. Likewise, the probability for a great increase of average intelligence in the last 35,000 years is also a very small one.
However, humans of a very high intelligence have a significantly lower number of rare functional alleles compared to people of normal intelligence (Spain, 2015). Therefore, this high intelligence appears to be an old and preserved one rather than a recently acquired one.
But de novo locus-specific mutation rates appear much higher for CNVs (copy number variants) than for SNPs. The estimates for CNV locus-specific mutation rates range from 1.7 x 10-6 to 1.0 x 10-4 per locus per generation, 100 to 10,000 times higher than nucleotide substitution rates (Zhang, 2009). And rare copy number deletions predict individual variance in intelligence (Yeo, 2011). Although each copy increase of subtype CON2 of DUF1220 domaine is associated with a 3.3-point increase in WISCH IQ and the copy number of DUF1220 domaine is implicated too in severe psychiatric disorders, like autism and schizophrenia (Davis, 2015).
A good indicator for brain functioning in a population is the prevalence of mental disorders. A study of the prevalence of psychiatric disorders in the USA, in the non-institutionalized population aged 15-54, found that nearly 50% of respondents reported at least one lifetime disorder and 30% of respondents reported at least one 12-month disorder. More than half of lifetime disorders occured in the 14% of population who had a history of at least three comorbid disorders (Kessler, 1994). Even if 14% (of those with disorders), representing alcohol-related pathology, are excluded, the prevalence remains very high. A meta-analysis based on 27 studies and a sample of 150,000 subjects aged 18 to 65, from 16 European countries, found a 27% prevalence of those affected by at least one mental disorder in the past 12 months (Wittchen, 2005). Personality disorders, being permanent, have an over 9% prevalence in the population of USA (Lezenweger, 2007). However, a Finnish study reveals a total prevalence of mental disorders of only 17,4%, the greatest prevalence being found between ages 50-64 (Lethinen, 1990). The heritability for each of these disorders is at least 40% (Burmeister, 2008).
Should natural selection have managed to increase intelligence in the las 35,000 years, then it should have also decreased the prevalence of mental disorders in the same period. In such a case, the Aurignacian population must have had not just a very low intelligence, but also a high rate of psychiatric disorders. However, it is the Finns who, being genetically closest to the Cro-Magnon human, latest abandoned his lifestyle, and had the least time available to adapt to modern life, yet they have the lowest prevalence of mental disorders. More logical, the Upper Paleolithic population had a better mental health compared to present day humans, while those from the latter with a better mental health are the ones who least and latest genetically drifted from the Cro-Magnon. In the same time, great differences in the prevalence of mental disorders in populations with common ancestry and similar present-day lifestyles, but with different histories, rather suggest the fragility of the human genome regarding brain functioning.
The selection pressure following the Aurignacian period was not powerful enough to counter the fragility of the human genome and to maintain brain volume and functioning, including intelligence, at the level back then.
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October 23rd, 2015
In 2012, Gerald Crabtree published an article (http://bmi205.stanford.edu/_media/crabtree-2.pdf) demonstrating the continuous decline of human intelligence (including emotional intelligence), starting thousands of years ago, through the large number of mutations (most unfavorable) which were not sanctioned by a lower and lower natural selection pressure, chiefly since the Neolithic age. As expected, the chorus of political correctness professionally optimists raised against Crabtree, stating that we live in the best age so far and that we are, certainly, the most intelligent of all humans who have lived until now… The racists too did not receive well Crabtree’s demonstration, most of them being convinced that the genotypic decrease of intelligence would be a recent only phenomenon (originating from the industrial revolution) which could somehow be stopped or even reversed…
Three years after Gerald Crabtree’s article, a study published in Nature (http://www.nature.com/mp/journal/vaop/ncurrent/full/mp2015108a.html) comes up and, without aiming to clarify the evolution of human intelligence in its history, it confirms the thesis of Crabtree (and of those who sustained this thesis before him, including the author of this text).
Searching for the heritability of intelligence, the study published in Nature compares the genome of 1400 highly intelligent humans (having an IQ>170; as a comparison, the average IQ of Nobel Prize laureates for science is 145) to the genome of a normal intelligence control group of 3000 individuals randomly assigned from the population, both groups belonging to the white race. The study did not find any specific genes for high intelligence present in the highly intelligent group and absent in the normal intelligence control group. On the other hand, it demonstrates that there is a lower frequency of functional rare alleles in the highly intelligent group than in the control group. Rare alleles are variants of common genes which result from mutations. They are less frequent because they appeared not so long ago and they had less generations available to disperse. They are new gene variants and mostly unfavourable, including to intelligence, as also revealed by this study.
Another study published in 2012 in Nature (http://www.nature.com/articles/nature11690.epdf) shows that a great majority of these rare alleles (and an even greater majority of the potentially harmful ones) emerged during the last 5,000 – 10,000 years. This is also the period of the greatest reduction in brain volume.
Therefore, highly intelligent individuals have more of the common (old) gene variants and less functional rare (new) gene variants in their genome than people of normal intelligence. However, there are much more people with a normal intelligence. This is just apparently a paradox, since the rare alleles number is very large and not all people carry the same rare alleles.
The more ancient a man is (meaning he has more old alleles and less new alleles), the more intelligent. This is in accordance with results from studying the Kostenki Man (a Cro-Magnon dating 36.000 years ago), who is genetically closest to the current northern European peoples (having the greatest IQ nowadays). Northern European peoples also posses the oldest gene variants.
The more we travel back in time, the less new genes will we find in a human population. Returning to the primary man, the Cro-Magnon (from whom all current Eurasians originate), we will find just old genes in his genome. Being the oldest man, he is the most intelligent of all having existed so far. This is concordant with also having had the largest brain volume, with about 250 cubic centimeters more than present-day Europeans.
Cro-Magnon is a Sapiens-Neanderthal hybrid and he resulted from an extraordinary selection pressure in the extremely harsh ice-age conditions. In that age, unfavorable mutations were eliminated while a favorable mutation (extremely infrequent) spread, because of natural selection, a phenomenon which does not exist nowadays.
Following the publishing of this study in august, in Nature, discussions over human intelligence evolution should have ceased: at least from the moment of climate warming, from the peak of the ice-age (25,000 years ago), intelligence began to drop and it kept dropping and it will drop in the future as well.
The current human is, in regards of both physical attributes and intelligence, just a degenerated Cro-Magnon, as well as the future human will inevitably be a degeneration of the current one. The super-human belongs to the past, not to the future as Nietzsche wrongly assumed…
We could also estimate this past super-human’s IQ: greater than 170…
October 21st, 2015
One year ago, the genome of a Cro-Magnon who had lived 36.000 years before us in western Russia, in Kostenki, has been analysed, results emphasizing that the northern paleolithic man was superior in both intelligence and character to the contemporary man.
From all current populations of Europe, the most genetically related to the Kostenki Man are the northern ones. These populations also have the highest IQ. And these, again, have the strongest character.
The more genetically similar to Cro-Magnon, the more intelligent a population is. Drifting away from Cro-Magnon and, implicitly, from his superior intelligence, took place through genetic mutations (most of which were unfavorable) unsanctioned by natural selection and passed on to subsequent generations.
Northern people were the last to drop the paleolithic hunter lifestyle and they lived in a harsh environment which did not allow for large populations. In a numerically reduced population, there are less genetic mutations. And these mutations are, on the other hand, eliminated by the action of a greater selection pressure, imposed by a northern climate and by a hunter’s lifestyle. It is, thus, easy to understand why, from all present day Europeans, the northern European is the most genetically related to the Cro-Magnon Man, and why the northern people have a higher IQ, and why the Cro-Magnon had a considerably higher intelligence than all current populations.
În 2012, Gerald Crabtree publica un articol (http://bmi205.stanford.edu/_media/crabtree-2.pdf) în care demonstra scăderea continuă a inteligenței umane (inclusiv a inteligenței emoționale), de mii de ani, prin numărul foarte mare de mutații (majoritatea fiind defavorabile) nesancționate de o selecție naturală cu o presiune tot mai scăzută, mai ales din neolitic încoace. Cum era de așteptat, împotriva lui Crabtree s-a ridicat imediat corul optimiștilor de profesie ai corectitudinii politice, după care trăim în cea mai bună dintre lumile de pînă acum și, desigur, sîntem cei mai inteligenți dintre toți oamenii care au trăit pînă acum… Și nici rasiștilor nu le-a picat prea bine demonstrația lui Crabtree, cei mai mulți dintre aceștia fiind încă convinși că scăderea genotipică a inteligenței ar fi doar un fenomen de dată recentă (cu originea în revoluția industrială) și un fenomen care ar putea fi cumva stopat sau chiar inversat…
La trei ani după articolul lui Gerald Crabtree, iată însă că apare un studiu în Nature (http://www.nature.com/mp/journal/vaop/ncurrent/full/mp2015108a.html) care, fără să își propună cumva să lămurească evoluția inteligenței umane în istoria ei, vine să confirme teza lui Crabtree (și a celor care au susținut această teză înaintea sa, printre care se află și autorul acestui text).
În încercarea de a căuta eritabilitatea inteligenței, studiul apărut în Nature compară genomul a 1400 de oameni cu o inteligență de vîrf (cu un IQ>170; pentru comparație, laureații Nobel în științe au un IQ mediu de 145) cu genomul unui grup de control cu inteligență normală, ales aleator din populație, de peste 3000 de indivizi,ambele grupuri aparținînd rasei albe.
Studiul nu găsește gene specifice inteligenței înalte, gene care să fie prezente la grupul cu inteligență de vîrf și absente la grupul martor, cu inteligență normală. În schimb, studiul demonstrează faptul că în genomul grupului celor cu inteligență foarte înaltă există o frecvență mai mică a allelelor rare funcționale decît în grupul de control. Allelele rare sînt variante ale genelor comune și sînt apărute în urma unor mutații. Sînt mai rare întrucît sînt apărute mai recent și au avut la dispoziție mai puține generații pentru a se răspîndi. Sînt variante de gene noi și sînt de cele mai multe ori defavorabile, inclusiv asupra inteligenței, cum arată și acest studiu.
Un alt studiu publicat in Nature in 2012 (http://www.nature.com/articles/nature11690.epdf?) arăta că majoritatea covîrșitoare a acestor allele rare (și o majoritate și mai largă a celor potențial dăunătoare) au apărut în ultimii 5.000-10.000 de ani. Aceasta este și perioada în care s-a produs cea mai accelerată scădere a volumului cerebral.
Astfel, oamenii foarte inteligenți au mai multe variante de gene comune (vechi) și mai puține variante de gene rare (noi) funcționale în genom decît oamenii cu inteligență normală. Totuși, oamenii cu inteligență normală sînt mult mai numeroși. Aceasta constituie doar aparent un paradox, pentru că numărul de allele rare este foarte mare și nu toți oamenii sînt purtătorii acelorași allele rare.
Cu cît un om este mai vechi (adică are mai multe gene vechi și mai puține noi), cu atît el este mai inteligent. Rezultatul e concordant și cu rezultatul studierii genomului Omului din Kostenki (un Cro-Magnon de acum 36.000 de ani), care este cel mai apropiat genetic, dintre populațiile europene actuale, de cele nordice, care au cel mai mare IQ. Avînd genomul cel mai apropiat de al lui Cro-Magnon, aceste populații au, deci, și variantele de gene cele mai vechi.
Cu cît ne întoarcem mai mult în timp, cu atît mai puține gene noi vom găsi într-o populație umană. Întorcîndu-ne la omul originar (din care se trag toți eurasiaticii de azi), la Cro-Magnon, vom găsi în genomul lui numai gene vechi. Fiind omul cel mai vechi, e cel mai inteligent dintre toți cei care au existat pînă acum. E concordant și cu faptul că e cel care a avut și cel mai mare creier, cam cu 250 cmc mai mare decit îl au europenii astăzi.
Cro-Magnon e un hibrid Sapiens-Neanderthal și e rezultatul unei formidabile presiuni de selecție, în condițiile extrem de aspre ale glaciațiunii. În acea vreme, mutațiile nefavorabile erau eliminate, iar o mutație favorabilă (caz extrem de rar) se răspîndea, datorită selecției naturale, fenomen inexistent astăzi.
După apariția acestui studiu publicat, în luna august, în Nature, discuțiile despre evoluția inteligenței umane ar trebui să înceteze: cel puțin din momentul în care clima a început să se încălzească, din momentul maximumului glacial (acum 25.000 de ani), inteligența a început să scadă și a scăzut continuu și va scădea și în viitor.
Iar omul actual nu e decît un Cro-Magnon degenerat, atît fizic cît și în ceea ce privește inteligența. Și omul viitorului va fi, inevitabil, o degenerare a omului actual. Supraomul aparține trecutului, nu viitorului, cum se înșela Nietzsche…
Putem avansa și o estimare a IQ-ului acestui Supraom: mai mare de 170…
În urmă cu un an, a fost studiat genomului unui Cro-Magnon care a trăit acum 36.000 de ani în vestul Rusiei, la Kostenki, iar rezultatele acestui studiu întăresc ideea că atît inteligența cît și caracterul omului paleolitic nordic erau superioare celor ale omului actual.
Dintre toate populațiile actuale ale Europei, cele mai înrudite genetic cu Omul din Kostenki sînt cele nordice. Dar aceste populații sînt cele care au și cel mai mare IQ. Și tot ele au și cel mai mult caracter.
Cu cît o populație e mai apropiată genetic de Cro-Magnon, cu atît mai inteligentă e acea populație. Îndepărtarea de Cro-Magnon și, implicit, îndepărtarea de inteligența superioară a acestuia s-a realizat prin mutațiile genetice (cele mai multe fiind nefavorabile) nesancționate de selecția naturală și transmise generațiilor ulterioare.
Nordicii au părăsit ultimii modul de viață al vînătorului paleolitic și au trăit într-un mediu aspru, care nu permitea supraviețuirea unor populații numeroase. Într-o populație redusă numeric mutațiile genetice sînt mai puține. Iar aceste mutații sînt, pe de altă parte, eliminate sub acțiunea unei mai puternice presiuni de selecție, impuse de condițiile climatice nordice și de modul de viață al vînătorului. Este, astfel, ușor de înțeles de ce europeanul nordic este cel mai apropiat genetic, dintre toți europenii de azi, de Omul de Cro-Magnon. Și de ce nordicii au un IQ mai mare decît ceilalți. Și de ce Cro-Magnon a avut o inteligență mult superioară tuturor populațiilor de astăzi.
When they started colonizing Tasmania, at the beginning of the 19th century, the British came to the conclusion that the inhabitants of that island were the least developed human community on Earth. The Tasmanian aborigines were incapable of mastering fire, they did not manufacture bone tools, they did not possess specialized stone tools, they did not use composite tools (e.g. axes with handles), they did not have boomerangs, spear launchers, shields, nor did they chop trees or engage in mural painting. Although they were living especially in coastal regions, the Tasmanians were incapable of fishing. Although they were living in a region with rather cold winters, they were not capable of sowing their own clothes – they could only cover their bodies with animal skins. Although they were members of the Homo Sapiens species, the material part of their civilization was inferior to the one achieved by the Homo Neanderthalensis and perhaps even by Homo Erectus (a species which most likely had already managed to master fire).
However, the British were not mistaken. The Tasmanian population was not the most evolved but the most degenerated in the entire world. The Tasmanian once had a superior material civilization, which included all of the achievements mentioned above, but which they lost in only a few thousand years.
The aborigines arrived in Tasmania at least 35,000-40,000 years ago, following a migration from Africa, along the Southern coast of Asia. At the time Tasmania was connected to Australia and only after the end of the last Ice Age did it become an island, as a consequence of a large part of the icecap melting and a rise in the water level. At the beginning of British colonization, the Tasmanian had been isolated from the rest of the world for more than 10,000 years. This was a period when they evolved on their own, without outside influence. The Tasmanian never actually suffered any British influence, as they were quickly exterminated.
Nobody provides a satisfying explanation for the degeneration of the Tasmanian civilization and that is because everything within human-related sciences is altered by various ideological filters.
’Scientists’ of political correctness (a new Inquisition of science) normally argue that the Tasmanian were too few to support civilization – even a Paleolithic-type one. It is estimated that the Tasmanian population amounted to 3,000-15,000 members. However, the Neanderthal population was of the same size, whose civilization not only did not degenerate over hundreds of thousands of years, but also continually evolved. In addition, contacts between human Neanderthal groups were not as frequent, as the area they covered was much larger than the one covered by Tasmanians. Hence, the small size of the population cannot be a serious argument for losing a certain level of civilization unless coupled with the distribution of intelligence according to the Gaussian curve. For a certain average IQ, it is necessary for a population to have a certain size in order to possess sufficient members with a sufficiently high level of intelligence in order to preserve the achievements of that civilization. For an average IQ of 60 (this was the measured IQ for Australian aborigines), the Tasmanians were too few to preserve their civilization. With an IQ which was probably much higher, the Neanderthals, although with a population not larger than the Tasmanian, had enough members to continually perfect their civilization. Nonetheless, the ’scientists’ of political correctness prefer to ignore the only plausible explanation for the degeneration of Tasmanian civilization and of any other civilization: the decrease of the IQ as a consequence of a decrease in the pressure of selection.
Racist scientists will not be particularly fond of this thesis either. If they accepted the genetic degradation of intelligence for the Tasmanian, they would then be forced to accept the same for other races which they see as being forever superior – something which would blow away the very foundations of their ideology.
Nature however does not take ideological whims into account. The decline of human intelligence has been ongoing for tens of thousands of years everywhere around the world. The cause is always the same: a lower level of natural selection.
As all other humans, except for the ones in Sub-Saharan Africa, the Tasmanians were not pure Homo Sapiens but hybrids. In their genome, around 4% were Neanderthal genes and equally around 4% were the genes of the Denisova hominin– the same proportions as for Melanesians and Australians This is already proof of the fact that at the peak of the Ice Age Tasmanian ancestors had reached sufficiently Northern latitudes to require a high level of intelligence.
The genetic degeneration of Tasmanian intelligence did not begin only once they were isolated on the island, but long before that. On the one hand, moving towards the South and living in the equatorial and tropical climate decreased the pressure of selection: humans required fewer calories in an environment which could provide more. On the other hand, hunting was (and especially so in Australia) much easier than in Asia while predators, human’s natural competition, were also more rudimentary and less intelligent. Moreover, as the region was not inhabited by other humans until this first migration, there was no human competition either. It is obvious that the humans who migrated to Tasmania were subject to a much lower pressure of selection than the humans who migrated towards Northern Eurasia. The fact is reflected by the current difference in IQ levels: the British Australian population has an IQ of 100 while the aborigines have an IQ of 60.
A similar phenomenon, although not of the same amplitude and duration, explains the IQ decrease for American natives. They originate in a Siberian population, of which probably only a few tens of thousands of members penetrated into America, about 11,000 years ago. They did so over the Behring Strait which at the time was no covered by waters but was a strip of land covered by ice. These humans were so intelligent and efficient that in approximately 1,000 years they managed to colonize the entire continent and exterminate 80% of the North American megafauna and 85% of the South American one. In the same millennium they managed to reach a population of millions of people. The price to be paid for this spectacular expansion was a decrease of the IQ (but not as dramatic as the one in Tasmania and Australia). Having a more numerous population with a higher IQ (today it stands at 87), the American natives not only did not lose the achievements of the civilization which they brought with them on the new continent; along with the end of the Ice Age, they managed to build much more complex civilizations, similar to the Eurasians: they invented agriculture, domesticated animals, processed metals, developed urban agglomerations and even empires, they gained scientific knowledge, etc. This additional development of civilization led to an additional decrease of the IQ. Following contact with European colonists, the IQ dropped even further – first through the decimation of American native elites and then by way of an accelerated reduction in the pressure of selection due to the Industrial Revolution.
Returning to the loss of Tasmanian civilization, the phenomenon which occurred on the little island illustrates the direction that the entire world is heading towards. The fall of civilizations consists of a loss of certain achievements (material or cultural). The Egyptians were no longer capable of building pyramids. The Greeks invented democracy but lost it. The world after the fall of the Roman Empire was no longer capable for a very long time of creating buildings that were similar to those of Roman engineers. In addition, as regards philosophy, science and art, the medieval world did not manage for very long to catch up with the ancient one. At all times and places, the fall of civilizations was due to the loss of IQ. The recovery of lost achievements always occurred only as a result of significant technological progress. Technological progress worked as prosthesis to replace the increasingly weaker minds of the ever larger share of the population. For instance, the general decline of IQ in the world leads to the consequence that fewer and fewer people are capable of solving simple arithmetic operations. But the invention of the calculator and its widespread use has enabled these people to reach correct results.
The genetic degradation of intelligence is, however, an inevitable phenomenon which is irreversible, global, whose beginnings can be found during the Upper Paleolithic and which will once day lead us all to the same situation as that of Tasmanians.
Ever since the emergence of computer-based tomography and magnetic resonance technologies, all studies that sought a connection between brain volume and intelligence have found a positive correlation. Statistically, those with larger brains are more intelligent than those with smaller brain volumes. In addition, brain volume and IQ are largely hereditary.
In spite of these indisputable results, which anyone can find in scientific publications from the past 20 years, promoters of political correctness still spread the lie in the general press that there is no link between brain size and intelligence. These advocates of a new Inquisition of Science, however, do not shy away from explaining the entire anthropogenesis through a growth in brain size, which enabled a growth in intelligence, as a consequence of a higher pressure of natural selection exerted precisely on intelligence. What has been true for millions of years simply disappears today, as if through magic, under the ideological order of political correctness.
The priests of racism do not deny the correlation between intelligence and brain volume, but instead use it to justify a lie: superior races (Caucasians and Mongoloids) have evolved during the last Ice Age and, since then, nothing has changed or will ever change again. Racists notice that the brains of Africans from the Sub-Saharan region are a few tens of cubic centimetres smaller than those of Eurasians and that Africans from the same region have an inferior IQ by a few dozens of points. This is all that is of interest to the racists. Beyond the present, nothing else matters. The period of time that has elapsed between the last Ice Age and today does not exist for the racists; it too disappears under the order of ideology.
All studies on brain volumes belonging to humans from the past have shown that, on all continents, they have decreased throughout the past 20,000-30,000 years. As a matter of fact, the most dramatic decrease can be noticed precisely in Caucasians – somewhere in the region of 200 cubic centimetres. If racists compared, using the same techniques that they use now, today’s Caucasian population with the Cro-Magnon, they would be compelled to accept that the difference in intelligence between our Palaeolithic ancestors and today’s Eurasians is more significant than any difference between any of the existing populations on Earth today. The entire structure of the racist ideology would collapse if one were to admit that today’s ’superior’ races – Caucasians and Mongoloids – are merely caricature-like degenerations of the Cro-Magnon, physically as well as (and even more so) from the perspective of intelligence.
As a matter of fact, all humans today are mere degenerations of yesterday’s humans, just as domestic animals are degenerations of wild animals. All studies show that animal brain volumes decrease following domestication. Thus, a dog even twice the size of a wolf will have a brain 10% smaller than the latter’s. Moreover, for similar sizes, the brain of a dog is 30% smaller than the brain of a wolf.
Just as in the world there are more and more dogs and fewer wolves, so there are more and more stupid people and fewer intelligent ones. The pressure of natural selection is no longer being exerted on human intelligence, just as there is no longer any pressure of selection exerted on the dog’s intelligence.
In order to have a suggestive image of phenomenon consisting of the decline in intelligence, all one needs to do is watch a map of the IQ levels throughout the world. The average intelligence on the planet today is 90 IQ points. The average IQ in more intelligent populations is 100-105. Keeping this IQ map in mind, let us remember that Koko the gorilla, raised and educated in a human environment, could achieve scores of 70-95 points in IQ tests. Because Koko had to overcome not only language and cultural barriers, but also the huge barrier between species, it is very likely that the IQ of this gorilla was higher than what her scores tended to indicate. Koko’s real intelligence is perhaps somewhere within the average values of human intelligence today and is perhaps even within the average values of those populations that racists label as superior.