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Totalitarianism-Crushes-Pollution-in-China (1)

Prof Zhang, Economist, Peking University says, regarding the results in his paper about the effects of pollution:

We are also puzzled by the difference in math and verbal tests as well as the gender difference.

Prof. Chew of National University of Singapore found similar results for college students, greater impact on male than on female students. He gave a talk last year at Peking University. However, in the later public version, his paper mainly emphasizes the impact on decision making. Perhaps he is leaving the findings on the impact on intelligence to another paper.

Because reviewers asked us to do so many robustness checks (in the end the appendix is 59 pages long), we didn’t have space to explore the heterogenous effect between rural and urban areas and across occupations in our paper.

In our paper, we didn’t compare the rural and urban sample. It is possible to run separate regressions to see if there are any systematic differences. Urban pollution has received more media attention although the surrounding areas may be more polluted. For example, most the pollutants for Beijing come from nearby counties in Hebei Provinces, where most polluted industries are located. In fact, air quality in many counties in Hebei province are worse than in Beijing.

In another related paper, we look at the impact of air pollution on happiness between those working indoors or outdoors and find indeed greater impact for those working outdoors. See the attached paper.

I suggested to Prof Zhang suppose that he might look back at those who were in very polluting occupations, and thus find the upper limits of the 3 year effect.

In summary, these are interesting findings which will have to be followed up. At the moment the reported effect of pollution is perplexing, and we may need a better model of how pollutants affect the nervous system.

• Category: Science 
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China AirPollution2

News has come in from China that air pollution has a large and cumulatively damaging effect on intelligence, particularly on older people with less education. Perplexingly, the effect is on Vocabulary, but not Maths. Even more specifically, the verbal decrement hits men harder than women. What is going on? How could bad air have such a specific effect, and all this within a mere 3 years?

In terms of the wider debate about whether intelligence tests mean anything, does this prove that intelligence tests actually test intelligence, or does it mean that they only test intelligence when measuring pollution, but not when they test differences between one person and another, or one group and another? Perplexing stuff. Odd that some critics who doubt that people can be validly tested for intelligence have no doubt about intelligence when the effect of a pollutant is identified.

However, in many eyes this paper about a pollution effect on intelligence proves the case for bicycles and the banning of diesels, or cars generally.

This would not be the first time that researchers have found that pollution damages the mind.

Those researchers found that for each 5ug/dl exposure at age 11 overall IQ dropped by 1.61 points. The effect on perceptual reasoning was a bit higher, the effect on working memory a bit lower, and nothing much on verbal comprehension.

What have the new researchers found?

The impact of exposure to air pollution on cognitive performance
Xin Zhanga, Xi Chenb, and Xiaobo Zhang

The paper is detailed, and carefully argued. Population sampling is very good. They studied sulphur dioxide, nitrogen oxide and particulates (PM10).

chinese pollution figures

A 1 SD increase in average API (exposure to pollution) over 3 years before the interview is associated with 1.132 points (0.108 SD) drop in verbal test scores.

Air pollution has a stronger effect on white matter (required more by verbal tests) than on gray matter (required more by math tests). Since men have a much smaller amount of white matter activated during intelligence tests, their cognitive performance, especially in the verbal domain, tends to be more affected by exposure to air pollution.

I am not sure why the response to overall pollution is so specific. It just seems odd. I am also not sure about the proffered explanation for the sex difference. It is based on a finding from Haier 2005 about white and grey matter activation in doing verbal and mathematical tasks. Anyway, they say it is a future research topic.

The scoring system is not the total number of items correct, but the highest rank of question achieved. This might introduce artefacts if the items are not perfectly ranked. It might also cause problems if the ranking of maths problems is easier to achieve than the rankings of word recognition. The test starts at different points according to the completed school stage of the participants. So, it is targeted at ability levels, and may be a little less reliable than a full test, but this is probably a minor issue. They control for family income and years of education, which will reduce individual variation in scores because such “corrections” assume that neither variables are caused by intelligence. They tested 25,486 respondents from the national sample, so perfectly good for this study. They omitted the 1.3% of subjects who had moved from one part of the country to the other (though with more time it would have been interesting to see if their results were affected by moving to more or less polluted places). They excluded those with very polluted occupations.

The population-weighted annual mean concentration of PM10 over 2014 in China is 112 μ g/m3, much higher than the National Ambient Air Quality Standards (NAAQS) published by the U.S. Environmental Protection Agency (EPA). This is a very important point in the supplementary materials, which in my view would have been better placed in the body of the main text. I could not find tables showing the effects for cities versus the countryside, which would have been informative.

It is good to see intelligence testing being used in this work. The results are interesting and quite alarming. However, it is hard to see how they could be having the particular reported effects on Vocabulary and not Maths, and for men more than women. If the very high level of pollution in China is having a massive impact then I would expect that no person or ability would remain unaffected. If pollution in 3 years is having such a big effect, even on Vocabulary alone, it is a puzzle that intellectual and scholastic achievement tests in China do not appear to reveal this effect, and regularly come well above Western achievements. The effect of pollution on intelligence is worth further investigation.

• Category: Science • Tags: China, Pollution 
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doer mountaineer

I intended to tell you about this paper some days ago, but for some reason didn’t get around to it. It was not procrastination on my part. Nothing so energetic as that.

Why is procrastination so prevalent? Why is it that I, of course not you, tend to postpone tasks, even on matters which are of interest to me but require exertion, and instead seek distraction? Why do I take all these pointless excursions into weather forecasts, updates on developing news stories, protracted discussions on the finer points of obscure technologies and sundry bits of trivia? Worse yet, why does the little I get done only happen in those brief moments when I tire of my own distractions, and the postponed task takes on its own aura of interest?

Enough of this. I must concentrate hard on this new paper which avers that the difference between doers and dreamers lies deep in the brain. Action control, they call it, and locate it in the amygdala. In my case Absolute Paralysis seems closer to the mark, but let us amble forwards.

The Structural and Functional Signature of Action Control
Caroline Schlüter, Christoph Fraenz, Marlies Pinnow, Patrick Friedrich, Onur Güntürkün, and Erhan Genç. Psychological Science 1-11. DOI: 10.1177/0956797618779380

Individuals differ in their ability to initiate self- and emotional-control mechanisms. These differences have been explicitly described in Kuhl’s action-control theory. Although interindividual differences in action control make a major contribution to our everyday life, their neural foundation remains unknown. Here, we measured action controI in a sample of 264 healthy adults and related interindividual differences in action control to variations in brain structure and resting-state connectivity. Our results demonstrate a significant negative correlation between decision-related action orientation (AOD) and amygdala volume. Further, we showed that the functional resting-state connectivity between the amygdala and the dorsal anterior cingulate cortex was significantly associated with AOD. Specifically, stronger functional connectivity was associated with higher AOD scores. These findings are the first to show that interindividual differences in action control, namely AOD, are based on the anatomical architecture and functional network of the amygdala.

The authors set out to look at why some people achieve their goals and others do not. Doers seem more capable of inhibiting irrelevant information, perhaps a frontal lobe function. The subjects were 264 university subjects, rarely the most representative human beings. They filled in a questionnaire about how they responded to reverses and disappointments; to boredom; and to distractions, to measure their action proneness on those three dimensions: 12 questions measured emotional preoccupation after failure; another 12 measured action versus hesitation in neutral circumstances; and 12 measured immersion in activities versus distractability.

Men were more able to get over emotions to reverses and disappointments than women, who tended to hold on to emotions and ruminate. However, when bored, men found it far more difficult than women to initiate new actions. Men and women were equally likely to remain immersed in an interesting activity.

The main finding when looking at all the subjects was that “individuals who are state oriented when it comes to initiating actions and therefore tend to hesitate or procrastinate show higher amygdala volume.” The correlation between amygdala size and the measure of action orientation was r= -0.235 which is not very big, but is the only area showing any noticeable correlation.

The authors say:

Thus, people with higher amygdala volume appear to be more state oriented and therefore tend to hesitate to initiate an intention and tend to delay the beginning of tasks without any good reason.

Regarding action control, this could mean that individuals with a larger amygdala volume have learned from past mistakes and evaluate future actions and their possible consequences more extensively. This, in turn, might lead to greater concern and hesitation, as observed in individuals with low AOD scores. Interestingly, it seems as if the amygdala is especially important when the results of a particular behavior are uncertain. This might explain why state-oriented individuals are especially vulnerable to the effects of uncontrollable outcomes and failures, whereas action-oriented individuals seem less affected by possible negative consequences.

In this population, it would seem that a large amygdala makes people fearful and therefore, in times of stress, hesitant and more likely to ruminate and procrastinate than leap to some concrete action.

Naturally, one has to be hesitant about this (perhaps I have a large amygdala), because the study is based on self-report rather than some experimental test of procrastination. Also, given that there are three major measures of action and 42 brain regions of interest, the sample size of 264 subjects, while having sufficient power, could still be prone chance findings.

This raises a more general issue: how do we ensure that we only compare brain regions with important aspects of behaviour, not a long list of possible one derived from countless questionnaires? One way would be to restrict brain scan studies to two measures: the general factor of intelligence and the general factor of personality. That would ensure that research focused on important matters. As ever, I can think of a counter-proposal. Perhaps the only important difference between one person and another, the only one which makes any impact on the world, is whether people get things done, or just dream about them.

Poetry makes nothing happen.

• Category: Science 
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doctor norman rockwell

You may remember my dictum: If you are fatter than you want to be, eat less.

That post led to an outpouring of deeply lived personal experience, of almost French complexity, extolling the virtues of eating particular food types in particular combinations at particular times, and not paying too much attention to calories. Fine. If you wish to be befuddled, that is your perfect right.

So, with some trepidation, here is a summary of the current state of knowledge regarding intelligence and health. Indeed, it is my summary of a summary paper. A pointless redundancy, you may say, but I know you are busy, and I would not like to interrupt your lunch break.

Intelligent people lead healthier lives, and that is not just because they intelligently make healthy decisions, but also, it would appear, because they are inherently healthier. Spooky.

What genome-wide association studies reveal about the association between intelligence and physical health, illness, and mortality
Ian JDeary 1 Sarah EHarris 12 W DavidHill 1

1 Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, United Kingdom
2Medical Genetics Section, Centre for Genomic & Experimental Medicine, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, United Kingdom

The associations between higher intelligence test scores from early life and later good health, fewer illnesses, and longer life are recent discoveries. Researchers are mapping the extent of these associations and trying to understanding them. Part of the intelligence-health association has genetic origins. Recent advances in molecular genetic technology and statistical analyses have revealed that: intelligence and many health outcomes are highly polygenic; and that modest but widespread genetic correlations exist between intelligence and health, illness and mortality. Causal accounts of intelligence-health associations are still poorly understood. The contribution of education and socio-economic status — both of which are partly genetic in origin — to the intelligence-health associations are being explored.

Until recently, an article on DNA-variant commonalities between intelligence and health would have been science fiction. Thirty years ago, we did not know that intelligence test scores were a predictor of mortality. Fifteen years ago, there were no genome-wide association studies. It was less than five years ago that the first molecular genetic correlations were performed between intelligence and health outcomes. These former blanks have been filled in; however, the fast progress and accumulation of findings in the field of genetic cognitive epidemiology have raised more questions. Individual differences in intelligence, as tested by psychometric tests, are quite stable from later childhood through adulthood to older age. The diverse cognitive test scores that are used to test mental capabilities form a multi-level hierarchy; about 40% or more of the overall variance is captured by a general cognitive factor with which all tests are correlated, and smaller amounts of variance are found in more specific cognitive domains (reasoning, memory, speed, verbal, and so forth). Twin, family and adoption studies indicated that there was moderate to high heritability of general cognitive ability in adulthood (from about 50–70%), with a lower heritability in childhood[4]. It has long been known that intelligence is a predictor of educational attainments and occupational position and success

In addition to mortality, intelligence test scores are associated with lower risk of many morbidities, such as cardiovascular disease, cerebrovascular disease, hypertension, cancers such as lung cancer, stroke, and many others, as obtained by self-report and objective assessment. Higher intelligence in youth is associated at age 24 with fewer hospital admissions, lower general medical practitioner costs, lower hospital costs, and less use of medical services, and intelligence appeared to account for the associations between education and such health outcomes. Higher intelligence is related to a higher likelihood of engaging in healthier behaviours, such as not smoking, quitting smoking, not binge drinking, having a more normal body mass index and avoiding obesity, taking more exercise, and eating a healthier diet.

All this work launched a new field: cognitive epidemiology. When studying health, factor in intelligence. If you read any research about a health problem, like for example obesity, always ask yourself the question: how much of this problem is associated with intelligence? Do they have early childhood data on ability and health? Without that, there is probable confounding.

The associations which are found between health and intelligence could be due to a direct genetic pathway shared by intelligence and health, and/or by better, more educated and wealthy intelligence choices.

Genome-wide association studies transformed the field. Box 1 summarises all the different statistical methods. This is a very good guide to the field. The main one is GWAS, which finds regions of the genome which are correlated with the trait in question and statistically significant at a P-value of <5 × 10−8 to control for the multiple comparison being made.

Here are all the correlations between the genetic code and health.
Table 1 here

genetic correlations with health

Another part of understanding the genetic contribution to intelligence health correlations concerns other predictors of health inequalities, and intelligence’s correlations with them. Intelligence is related to education and socio-economic status (SES), and those were known to be related to health inequalities before intelligence was known to have health associations. Although education and SES are principally thought of as social-environmental variables, both have been found to be partly heritable, by both twin-based and molecular genetic studies, both have high genetic correlations with intelligence, Mendelian Randomisation results show bidirectional genetic effects between intelligence and education, and both have genetic correlations with health outcomes

What does all this mean? It may mean that the underlying causes of health, happiness, morbidity and mortality are unequally distributed, and favour some people more than others. Evolution does not have to conform to our imaginings or our notions of fairness. If genetics is a significant contributor within a genetic group, it is plausible that it contributes to between group variance. Perhaps the Japanese live longer because they are Japanese. This remains to be proved, but is worth testing. If we ever achieve the noble ambition of creating healthy environments all over the inhabited world we may yet have a residuum of health differences due to purely genetic causes.

• Category: Science • Tags: Diet, Health 
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Pressure and Ike

This play is about James Stagg who was in overall charge of predicting the weather for the D-Day landings. He had four days in which to provide his advice, and was up against a successful American forecaster, who already had the ear of the Supreme Commander, Dwight Eisenhower.

You may quail at the thought of any play being based on a weather forecast, the main prop being a pressure chart of the Northern Atlantic, and all the action being in a sparsely furnished room, the few props being weather recording instruments. Sure, there is a romantic story about Ike’s relationship with Kay Summersby, his car driver, who was also his lover and general therapist, but this is a play about the difficulty of communicating science.

Pressure Ike-Stagg

Since this is a London play ending at the close of August, I doubt my explanations will spoil anything for most of you, but it is a lovely story about the dilemmas of being an expert witness. Whatever the cost, or the pressure to give the desired answers to power, predictive accuracy is the scientific goal, and James Stagg stuck to his guns, on the basis of a gut feeling about imperfect data, guided by a general three-dimensional model for which he had only partial support.

James Stagg

David Haig wrote the play, and takes the part of James Stagg. Malcolm Sinclair is a very convincing General Eisenhower and Laura Rogers a charming, long-suffering Kay Summersby. All the players were excellent, so one can suspend belief and just enjoy the story.

James Stagg had to explain that in his view all forecasts based on historical records were dubious, and all forecasts based on air pressure charts were flawed because they were two dimensional. He had to explain a recently observed phenomenon (which all of us now take for granted) based on two pilots who reported that they had completed their flights from America to England particularly quickly, because at high altitude they had benefited from a very high tail wind of about 130 miles per hour. This was, as the American forecaster pointed out, a very small sample.

Stagg argued that this jet stream, as we now call it, would pull in the Atlantic storms to the Channel on the intended D day of 5th June. The American argued that the fast moving northward good weather from the Azores would triumph, and that the jet stream was an irrelevance in the general picture. After frenzied discussion the invasion was postponed, possibly for weeks, with potentially lethal military effects because the element of surprise would be lost and the deception plan rendered useless, since there were few practicable days when the tides were favourable. Stagg thought he could see a one day pause in the storm, so Eisenhower took the gamble, and the invasion took place the following day, 6th June 1944.

The attraction of this story should be obvious to all researchers. It was an instance when history turned on a complex point of meteorology, and the supposedly supreme command was subservient to the weather. It is not often that governments ask for true advice, and unusual that they want the real answer, even if it is highly unpleasant. War is a hard taskmaster. Of course, it has another parallel in the climate change debate: who does one trust to make the correct predictions, in this case for events that may take decades to be tested?

Will a government ever ask psychometricians for advice, and change policies as a result? In my view that is highly unlikely. So, it is entertaining to find that at least one weatherman had his day in court and changed the course of history.

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naipaul indian

I think I started with “In a Free State” (1971) which captivated me. Then “The Loss of El Dorado” (1969),“The Enigma of Arrival” (1987) and many of his essays. There must have been some others, perhaps even the early novels. Some of those books must be kicking around in the cottage somewhere. That’s enough to tell the basic story.

Naipaul was In a Free State, being genetically Indian, culturally English, and born in the Caribbean, which he regarded as a mistake. He left as soon as he could. In England he was a Wog, finding it hard to get work and, far more importantly, to get girls. He somewhat reluctantly married the one girl he met at university, as shy as him. He depended on her support for the rest of her life. Sex with her was not very sexy. The love of his life was Anglo-Argentine woman, met years later in Buenos Aires, courted in Bariloche, and he lived in a loose menage a trois for 24 years. No respecter of icons, he wrote an essay about Evita and, among other things, her prowess in fellatio (1980). He had sharp words for Africans, Indians and for a selection white people. He was disdainful, did not suffer fools, and wrote with style. He had the knack of comedy, and the grandeur of great novelists in his deep despair at human nature. He took his time over his prose, sometimes three years for one book.

He felt “The loss of El Dorado” deeply, and showed how the colonial search for gold was both a chimera and a curse. The colonists found gold and silver in plenty, and badly mistreated the natives, but their plunder hampered them, so they lost out in the industrial revolution centuries later. Easy money corrupts. Naipaul was a great admirer of Bartolome de las Casas, the defender of the rights of the indigenous natives. Naipaul had great hopes for the book, thinking it would be a best seller in the US, but it bombed. The market for colonial history is smaller than he hoped.

I read his book in Wiltshire, eventually finding out in “The Enigma of Arrival” that he lived much of his time not far away in the beautiful Woodford valley, as English as it is possible to be. But he was never fully there, despite his knighthood, and Nobel prize. He was a dark-skinned kid from Trinidad. As he flew away from there to Oxford a friend told him to sit at the back of the little plane, because it was safer in a crash. As it circled upwards he looked down at his homeland and young life, and thought it all absurd, a pointlessly small island in the vast ocean. Yet, it was that enigma which drove him on an endless quest to find a home: a scholarship boy running away from the sunlight to the cloudy place where books came from.

For any transient Naipaul is a visionary. He was yet another miniscule iron filing being drawn North by a magnetic pole. He was a master of the ambiguity of belonging while not belonging. England Made Him. Many have straddled the Anglo divide, but what Naipaul wrote about was gruel to all immigrants: the sense that they were imposters in every country they touched; that their supposedly exotic childhood was pretty boring; that the real story was in London, Paris and New York; and that after all that the continuing story was a free state which combined enigma and loss, the loss of that very origin which was most disparaged and yet most vivid.

One of my first radio interviews, perhaps in 1980, was in the old Langham Hotel which had been taken over by the BBC and was a stale corporate ruin. It was there that Naipaul started his writing, on the rustle-proof paper specially provided for announcers. As I walked through the corridors I wondered where he had got to. He seemed always at one remove, writing from distant places with detached amusement about human frailty, and travelling around trying to make sense of who he was. India was not exactly to his taste, neither was the Muslim revival, and neither was the England of 1972 and its dismay at having to offer refuge to the Ugandan Asian ejected by Idi Amin.

An author is often a transient, never entirely rooted in cultures they must observe with detachment, in order to be able to laugh at pretensions, point out errors, find points of redemption and, above all, tell a story which engages those too involved with life to be able to notice what travellers see through the back windows of the house.

In the end, it turned out that after decades of searching, that Naipaul was nearby, and I met him on this day two years ago. I say “met” to give it importance. It was little more than a friendly nod, repeated once or twice some months later, no more than that, but a big deal for me.

In the “Enigma of Arrival” Naipaul recounts the walks he took through the countryside during breaks in writing. Sometimes he met an old man, who made his way across the barbed-wire fences by wrapping plastic bags over the spikes, and tying them up with string, so that they made a padded tube over which he could step. Naipaul made it seem a distant relationship, of the restrained head-nodding type, but it was part of his general pensive theme about how everyone fits in to their landscape, though that landscape changes. Later on in the book he notes that, quite without realizing it, he no longer had seen the old man again, and that all that was left of him was plastic bags tied to barbed wire. I sometime think that Naipaul was talking about himself, and thought of his books in that way.

Authors have great power over us readers. We let them drive the car of our imagination, at speeds and on journeys of their choosing, and let them hold the keys for ever.

Thank you, Vidiadhar Surajprasad Naipaul.

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boost your iq brain

You may wonder why I have stooped to the filthy practice of ripping off the gullible public. Although described as gullible, they are bright enough to know that there is advantage to being brighter, and are willing to pay for intelligence boosting techniques. Their gullibility, such as it is, is based on believing that most people are honest, and that nice people would not be offering brain training unless it honestly conferred an advantage.

As we know only too well, these training techniques don’t work, and at best have only very limited and circumscribed benefits. Furthermore, there are so many salesmen offering such training courses that you may wish to restrain me not on moral grounds but simply because my efforts will be wasted. The most plausible salesmen, traffickers in hope, have already got the ear of governments, and ready access to taxpayer’s funds, so I am far too late to make my millions.

Thank you, but in this case the $75 is going the other way. That is to say, will intelligence test-taking performance increase if people are paid $75 to do well on the test? This is an interesting question, because critics of intelligence testing have argued that some groups get low scores because they are not interested in the test, and can’t see the point of solving the problems. Perhaps so, although if you don’t get motivated by trying to solve problems that might be diagnostic in itself.

Gilles Gignac decided to have a look at this argument, seeing whether the offer of winning $75 Australian dollars boosted intelligence test scores in university students. For once, I am not too bothered by the subjects being university students, because they tend to have modest funds and healthy appetites. $75 buys 30 tinnies of beer, or 13 bottles of cheapish wine. Enough said.

A moderate financial incentive can increase effort, but not intelligence test performance in adult volunteers. Gilles E. Gignac, School of Psychology, University of Western Australia, Crawley, Western Australia, Australia
British Journal of Psychology (2018)

The setup was detailed, using a counter-balance design, and the end results are pretty clear:

We conducted an experiment with 99 adult volunteers who completed a battery of intelligence tests under two conditions: no financial incentive and financial incentive (counterbalanced). We also measured self-reported test-taking importance and effort at time 1 and time 2. The financial incentive was observed to impact test-taking effort statistically significantly. By contrast, no statistically significant effects were observed for the intelligence test performance scores. Finally, the intelligence test scores were found to correlate positively with both test-taking importance (rc=.28) and effort (rc=.37), although only effort correlated uniquely with intelligence (partial rc=.26). In conjunction with other empirical research, it is concluded that a financial incentive can increase test-taking effort. However, the potential effects on intelligence test performance in adult volunteers seem limited.

There is one set of tasks where being paid to do them seems to have an effect. These are simple, repetitive processing tasks, as shown in Table 1 below.

Boost IQ 75

By the way, this is not to say that processing tasks are a bad measure of intelligence. Under normal circumstances they work fine, but they can be influence by rewards in a way that more g loaded tasks cannot be.


Clear evidence for the contention that intelligence test scores are, to some appreciable degree, invalid due to individual differences in test-taking motivation remains to be reported, at least for adult volunteer samples. Consequently, the substantial validity coefficients reported in the literature supporting the interpretation of IQ scores may not be as biased upwardly as some have suggested, based on analyses of non-adult samples (e.g., Duckworth et al., 2011). As absence of evidence is not evidence of absence, we encourage more research to help understand precisely why test-taking motivation and intelligence test scores are correlated positively in both children and adults.

One reason why test-taking motivation is correlated with intelligence test scores may be that bright people like solving problems. If they have to take a test, they look forward to it, knowing they usually do well, and are interested in finding out precisely how well they do. Less able students don’t like tests, and particularly get discouraged when they relate to difficult subjects.

• Category: Science 
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Goldie Hawn and daughter

It is usual to bemoan the way newspapers report science, but that criticism is amply justified when they make major errors.

You may have heard of Carl Zimmer’s “She has her mother’s laugh: The Powers, Perversions and Potential of Heredity”, and probably read some reviews. Greg Cochran did one for Quillette.

The book has now been reviewed in the Sunday Times, the largest selling quality Sunday newspaper in Britain. To assist those who may not have come across the concept of heredity, the review had a picture of Goldie Hawn and her daughter. They look very similar.

Readers are told that:

“once you get past your great-grandparents you will find some of your ancestors who share none of your DNA. They are still your ancestors but DNA gets so sliced and diced down the generations that all you are going to learn is that you are, like everybody else, a bewildering genetic salad”.

“Nazism showed the most persistent and lethal hereditary superstition is race. This because it seems to be visible; blacks, white and Asians just look different. The killer point here is that genetic diversity within populations is far greater that between populations. In other words, if you are white and meet a black man and a white man, you are quite likely to be more closely related to the black man. Race has no basis in genetics.”

Lewontin never dies! I suppose a few readers may wonder how it is “quite likely” that a white man can be more closely related to a black man than a white man, and how it is that black parents reliably have black children. The answer seems to lie in the genetic salad. Newspaper reporting of this low quality may explain the uphill struggle we encounter when discussing group differences.

• Category: Science 
Brain training, mindset, grit, deliberate practice and bilingualism.
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Brain training

I hesitate to suggest that my readers might ever have felt the need to improve their mental abilities by conducting specific mental exercises, but you may have a friend who wants to dabble in these practices, so this little note is for your friend.

Overstating the Role of Environmental Factors in Success: A Cautionary Note
David Moreau
Brooke Macnamara
Zach Hambrick
Created on: July 31, 2018 | Last edited: July 31, 2018

Your friend may have been ensnared by the following:

Thousands of scientific articles have been published on these topics, which have also captured the popular imagination through books such as Smarter: The new science of building brain power (Hurley, 2014), Mindset: The new psychology of success (Dweck, 2006), Grit: The power of passion and perseverance (Duckworth, 2016), and Peak: The new science of expertise (Ericsson & Pool, 2017).

Why are these notions so attractive? I think that most people would like to be cleverer, and the idea of a shortcut is alluring. Spend a short time mastering a training routine, and then the mysteries of the universe will open up for you. This is an old dream. Jude the Obscure desperately wanted to learn other languages, and was extremely disappointed to find out that the language learning books, far from teaching him a language learning trick as he imagined, were simply long lists of things that he had to learn. Reality can be tedious.

Brain training

Thesis: the brain is like a muscle which needs exercise. Er, not really. There is some evidence for “near transfer” of specific skills but no convincing evidence for “far transfer”, as when the specific learned skill leads to improvements in other wider abilities.

Meta-analysis by Melby-Lervåg and Hulme (2013), found “no convincing evidence of the generalization of working memory training to other skills” (p. 270). They also noted that working memory training studies are often plagued by major methodological problems, including use of research designs without appropriate control groups. More recently, Simons and colleagues conducted an exhaustive review of the available evidence for benefits of brain training and concluded that “the evidence that training with commercial brain-training software can enhance cognition outside the laboratory is limited and inconsistent” (Simons et al., 2016, p. 173). Finally, in a meta-analysis examining brain training in the form of playing video games, Sala, Tatlidil, and Gobet (2017) “found no evidence of a causal relationship between playing video games and enhanced cognitive ability” (p. 111).

So, nothing in it.


Whereas the idea of brain training is to directly strengthen cognitive abilities, the aim of mindset interventions is to increase people’s beliefs that they can be strengthened. A growth mindset is assumed to be a good thing.

Across three studies with a total sample over 600 participants, Li and Bates (2017) found “no support for mindset-effects on cognitive ability, response to challenge, or educational progress” (p. 2). Furthermore, in a recent meta-analysis, Sisk, Burgoyne, Sun, Butler, and Macnamara (2018) examined the effectiveness of growth mindset interventions on academic achievement and identified a number of methodological shortcomings among mindset studies, such as many instances of manipulation checks either not being successful or not being reported. Sisk et al. found that the effectiveness of mindset interventions on academic achievement was very weak overall, with almost all analyses yielding small or null effects. They concluded that “those seeking more than modest effects or effects for all students are unlikely to find them” (p. 568).

Nothing in it.


Grit refers to perseverance. This must be a good thing, surely?

However, in a study of 4,642 twins, Rimfeld, Kovas, Dale, and Plomin (2016) found that grit was substantially heritable, but found no evidence for a shared environmental influence on grit. Rimfeld et al. explained that “[t]he most limiting finding, for any possible intervention, is that shared environmental influence is negligible” (p. 786). In other words, current environmental factors such as how parents raise their children or approaches schools take to teaching do not appear to influence grit.

We are often told that the fact that a trait is heritable does not mean that it cannot be manipulated by environmental means. True, as a general warning, but in this case it seems to be the case that the trait is heritable and not manipulatable by educational means.

Evidence further suggests that, even if grit is found to be trainable, it may have no impact on academic achievement above and beyond other personality factors.

“overall grit explains no variance in either overall academic performance or high school GPA after controlling for conscientiousness” (p. 501).

Despite these negative findings, training in GRIT is an educational priority in the US and UK.

So, to have a persevering approach to learning is a good thing, but seems to be a personal characteristic which cannot be altered so as to make a difference to academic achievement.

Persevering is good, but training people to persevere? Nothing in it.

Deliberate practice

Practice, practice, practice. What could be wrong with that? Well, it could be a great time-waster for those who lack talent, and should be doing something else.

There is no question that deliberate practice can lead to major improvements in performance within an individual. The controversial claim is that deliberate practice can largely explain differences in performance across individuals. This claim is not supported by empirical evidence. In a recent meta-analysis, Macnamara, Hambrick, and Oswald (2014) found that deliberate practice leaves the majority of variance in performance across individuals unexplained and potentially explainable by other factors (see also Platz et al., 2014). In another meta-analysis, Macnamara, Moreau, and Hambrick (2016) found that deliberate practice accounted for a non-significant 1% of the variance in performance among elite-level athletes, inconsistent with Ericsson and colleagues’ (1993) claim that “[i]ndividual differences, even among elite performers, are closely related to assessed amounts of deliberate practice” (p. 363). Furthermore, Macnamara et al. (2016) found that higher-level athletes were no more likely to have begun practicing their sport at a younger age than their lower-level counterparts. Together, this evidence indicates that deliberate practice is not the only important contributor to individual differences in expertise.

Nothing in it for those without talent, something in it for those with talent.

Bilingual advantage

La idea que hablar dos idiomas mejora la inteligencia.

• Category: Science • Tags: IQ, Nature vs. Nurture 
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synapse labelled by lee

It is a great pleasure to see that a massive new study on intelligence has just been published, after years of work and also months of publication delays. Anything which can be done to speed up the publication of results is to be welcomed. Research has now moved to an international dimension, with disparate groups being managed and cajoled into cooperative ventures, a major undertaking that requires academia to develop new skills of diplomacy, coordination of disparate research groups, careful assembly of very different data formats and research protocols, and a sensitive understanding of individual egos and conflicting cultural and political sensitivities.

In contrast, all that is required of a commentator is patience, in this case a year of waiting.

Gene discovery and polygenic prediction from a genome-wide association study of educational attainment in 1.1 million individuals. James Lee et al. Nature Genetics, 2018

It is a very long paper, almost book size, because it has to cover so much ground. The table of contents lists 205 pages, of which 149 are explanatory text. Happily, supplementary figure 8 provides me with a picture I can use instead of having to explain everything. The picture (shown above) encapsulates the vast strides that have been taken in linking genetic research to the terra incognita of the synaptic gap which, if I thought about it at all as an undergraduate, seemed simply a mysterious chemical soup which passed message on upstairs to the brain, my main focus of interest. Now we have not only a diagram of the transmitter exchanges but linkage to the snippets of genetic code which lead to the actual processes.

First, a little comment about “years of education”. I think of this as a weak proxy for intelligence, and that it is used simply because the data are more widely available than intelligence test results. It will still be picking up interesting things, but will under-record pure intelligence. To look at the extent of this difference, look at other studies which have used actual intelligence test results, and you will find that they seem to tap into the same areas. When that is done, the correlation between intelligence and years of education is 0.7 which is perfectly respectable, and as high as correlations between Wechsler subtests. Also, see below for a comparison done within the study using two intelligence tests.

Second, in terms of the history of this research, this paper is EA3 (educational attainment 3rd sample) and follows on from previous work EA1 and EA2. Internationally there is some overlap and repetition in papers from other labs, and we probably need to explain these better. You may remember that last September I hoped “someone somewhere is keeping track of the overall picture, perhaps in a control room with multiple screens, like the NASA control centre of old, tracking the orbit of each SNP as it hoves into sight.” Not yet.

Third, the bulk of the paper is about the methods used to put together the samples into one big data base and all the corrections and assumptions which go into detecting the genetic signal within the noise. Some analyses, for example within-family studies, cannot be done reliably without 47,000 sibling pairs and they had only 22,135 identified, so they do only some restricted inferential work. A great deal has to be said about all these statistical matters, and the paper serves as a text for where the field has reached at the moment. Other leading labs will pile in with their detailed observations in due course. Please note the quaintly named “Winner’s Curse Adjustment”.

In this section the authors say:

Using a large sample of genotyped parent-child pairs from Iceland, the study documented that a polygenic score for EduYears constructed entirely from non-transmitted parental alleles predicts a respondent’s educational attainment. A plausible interpretation of this finding is that non-transmitted alleles are associated with EduYears through their effects on the child’s rearing environment. The effect of a polygenic score based on non-transmitted alleles was approximately 30% as large as the effect of a polygenic score based on transmitted alleles. An analogous analysis of height found that the effect of the non-transmitted-allele score was 6% as large as the effect of the transmitted allele score.

I find this difficult to take in, because the idea of the “child that you could have been” and “the parents you could have had” are new to me. However, the paper argues that an effect going from parent genotype, to parent phenotype, to offspring phenotype, is a very plausible explanation of the smaller effects inferred from the within-family studies than from the population GWAS. Assortative mating probably makes some contribution to the discrepancy as well.

As shown in Supplementary Table 38, in Add Health, a one-standard-deviation increase in the score is associated with a 4.7 percentage-point increase in the probability of completing high school incremental pseudo- R2=6.2%), a 15.6 percentage-point increase in the probability of completing college (incremental pseudo-R2=9.5%), and a 7.1 percentage-point reduction in the probability of having retaken a grade (incremental pseudo-R2=4.0%).

Here are the findings in a histogram:

Lee poly score and education achievement

Now consider, as Steve Hsu has done, the opportunity faced by parents who are having IVF because their genes contain a risk factor for Huntington’s chorea, or cystic fibrosis, or some other awful disorder, such that their petri dish embryos have to be screened before the best one is implanted in the womb. A doctor might say, very privately, to the parents “We have knocked out the genes for disease X as requested. All these 10 embryos will be fine. Would you like us to select the one of those 10 most likely to complete high school? Entirely up to you”.

• Category: Science • Tags: Genetics, IQ 
James Thompson
About James Thompson

James Thompson has lectured in Psychology at the University of London all his working life. His first publication and conference presentation was a critique of Jensen’s 1969 paper, with Arthur Jensen in the audience. He also taught Arthur how to use an English public telephone. Many topics have taken up his attention since then, but mostly he comments on intelligence research.