Wednesday 31 July 2013

We mustn’t label children, or educationalists

The above link, if you listen to it 16mins and 30 seconds in from the start, is a BBC radio interview with Prof Plomin, talking about the high heritability of scholastic attainment. This high heritability is because of the high heritability of intelligence as a causal variable, and presumably also because of the heritability of associated personality variables conducive to conscientious study.

A direct heritability estimate for scholastic achievement is a considerable step forward. Two thirds of the variance is impressive. It equals the correlation between intelligence and reading found by Rutter and Yule in their Isle of Wight studies 40 years ago, a result which pre-figures this one, and is closely related to it.

Plomin’s findings led to confused questions about whether it is worth while paying a lot of heed to educational interventions when so much of the variance is genetic. In strict terms, the heritability estimate is based on the relative contribution of genetic variation, but only given a particular social and educational environment. For example, it assumes that the UK’s relatively wealthy and peaceful society functions as before, with free health services, free schools, subsidised benefits and all the rest of it. Removing such advantages would boost the contribution of the environment, to the extent that even lower quality schooling and living standards would depress the level of achievement. Bad circumstances boost the amount of variance accounted for by the environment. Good circumstances reduce the environment’s contribution to variance.

That is, we expect a poorer school environment would reduce scholastic attainment. We cannot be sure how much is transmitted culturally by families, even when school systems are very poor. There is no getting away from the finding that if two thirds of the variance can be explained by individual differences in the genetic code, then the remaining third is an unknown blend of other family differences (bright parents helping their children with their homework, for example), peer group influences, and the school effect, such as it is. Some of the apparently great differences between different schools and different teaching methods may well be unsubstantiated. Perhaps a benefit of understanding this would be for parents to be more relaxed about school league tables, and concentrate on helping their child learn at the pace and in the style best suited to them.

The teacher asked to comment on the radio programme feared, quite understandably, that genetic screening of children would lead to self-confirming prophecies, and well they might. That danger must be balanced against the larger danger that a relatively standard form and pace of instruction fails to meet the needs of children with widely differing intellectual demands. Most children quickly work out the braininess of their classmates, if only because every lesson gives them plentiful evidence of human differences, so labelling is there even if teachers avoid it.

Another reason for listening to the interview is to hear a researcher keeping calm and explaining the main findings without exasperation. In the wish to avoid labelling children, many UK schools have also avoided tailoring their teaching to the needs of pupils, particularly the brighter ones. Plomin, the first in his family to get a university education, and aware from an early age that he needed to get books from the Chicago public library to feed his curiosity, must have been tempted to champion the cause of bright children, and the benefits of fitting education to their intellectual needs. He kept his cool. Calmness is required if we are to climb the mountain of fear and rejection which surrounds individual differences, particularly those differences which allow one person to think five times faster than another.

Overview of the Flynn Effect


Robert Williams gives an overview of the putative main drivers of the effect. He notes that far from being uniform, “the gains have been large, small, variable and even negative”. Some researchers have found that the gains were on g loaded items, whilst more have found no g loadings, suggesting that the gains may be empty. The rate of gain varies by the dates chosen for study. Data from behind the former Iron Curtain countries are particularly informative, since there have been real changes in education and in society. A feature of the literature is the frequent contradictions: for every finding there seems to be an opposite finding. As to causes: education may be a driver of change in emerging nations, but probably no longer in wealthy nations; test sophistication is no longer much of an issue; guessing answers may boost gains somewhat; nutrition may boost gains, particularly at the lower levels; nutrition may be boosting both height and intelligence, but not in the same way at the same times; measurement invariance strongly suggests that the meaning of IQ is not constant over time. Williams says: “It is likely that most of the Flynn Effect gains that have been reported are hollow”. However, he also says that the effect remains enigmatic because there are varying combinations of multiple drivers, and methodological problems are confounded with real world issues.

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If you want to you can use the email alert option “Follow by email”  to the right of this screen, which alerts you to the next posting. As far as I can see, all that the Google system does is to alert you by email, and nothing else. I do not see the email addresses themselves, but only the total number of persons using the service.

Tuesday 30 July 2013

Editorial: Intelligence: Special Issue: Flynn Effect



Cohorts differ in their abilities, and we do not know why. Wines also differ, with some years being better than others, some famously so. Choice generations sparkle like champagne, with bright bubbles of innovation and discovery followed by longer periods of duller harvests and flatter discourse. These differences in comparative brilliance are rightly a matter of interest and speculation, particularly when it seems that, on the basis of IQ test results alone, throughout much of the 20th century everyone was getting brighter. This is not impossible. Better techniques of viniculture have improved many a new entrant to the global wine trade, but if humans are improving so much, it would be nice to know how this is being achieved.

The term “Flynn effect” was coined by Herrnstein & Murray (1994, The Bell Curve, p. 307) to designate the increases in IQs during the twentieth century that were documented for the United States and for a number of other countries by Flynn (1984, 1987). Herrnstein and Murray were explicit that the phenomenon was observable in the 1930s but that Flynn had drawn attention to it. Jim Flynn was not able to prevent this ennoblement, which was itself a clear instance of the Herrnstein and Murray effect, in which a finding is attributed to someone who was not the first to find it. I doubt they were the first to do this, since contested parentage is generally true of all effects named after a single person.

Of course, whatever the name of the effect, we must distinguish between IQ gains and IQ inflation. Large numbers impress, and rising apparent wealth often comforts even those faced with the reality of rising inflation. Many national examinations report higher pass rates every year. Students may be getting brighter or examiners may be getting kinder. Exam results are silent on this issue, unless we can find objective measures. Intelligence tests are great for ranking individuals within a contemporary population, and have excellent predictive value, but they are not particularly good at comparing generations. They weren't designed to do that, though it might be achieved by lengthening those parts of the test which can be defined in terms of some intrinsic measure of difficulty, perhaps in mathematics.

What made the Flynn effect notable was its apparently relentless and steady progress. Like the application of nitrogen fertiliser to crops, something in the decades after the Second World War seemed to be boosting IQ scores at the predictable rate of about 3 points per decade. All that was lacking was to find the miracle ingredient. Many causes were proposed, yet few came close to fitting the data. In some ways the early results made more sense. It seemed as if duller citizens were being boosted into the average range: yet another example of the benefits of humane and kindly welfare states. Then more results came in suggesting that average and above average citizens were also getting the benefits of the mysterious ingredients. All were getting prizes. By the turn of the century the effect seemed to be coming to a halt in some wealthy countries, whilst starting off in poorer countries with emerging economies.

The results have always prompted a cynical response: if everyone is getting brighter, why are so many people still behaving stupidly? Where are all the geniuses? Where are all the new inventions and breakthroughs in understanding which would match the IQ results? Recursively, if we are as bright as the Flynn effect suggests, why can't we get to the bottom of the Flynn effect?

This special issue attempts to push on the debate, whilst being aware that it cannot resolve it.

Robert Williams gives an overview of the putative main drivers of the effect. He notes that far from being uniform, “the gains have been large, small, variable and even negative”. Some researchers have found that the gains were on g loaded items, whilst more have found no g loadings, suggesting that the gains may be empty. The rate of gain varies by the dates chosen for study. Data from behind the former Iron Curtain countries are particularly informative, since there have been real changes in education and in society. A feature of the literature is the frequent contradictions: for every finding there seems to be an opposite finding. As to causes: education may be a driver of change in emerging nations, but probably no longer in wealthy nations; test sophistication is no longer much of an issue; guessing answers may boost gains somewhat; nutrition may boost gains, particularly at the lower levels; nutrition may be boosting both height and intelligence, but not in the same way at the same times; measurement invariance strongly suggests that the meaning of IQ is not constant over time. Williams says: “It is likely that most of the Flynn Effect gains that have been reported are hollow”. However, he also says that the effect remains enigmatic because there are varying combinations of multiple drivers, and methodological problems are confounded with real world issues.

Richard Lynn looks back at the pre-history of the Flynn effect, finding early studies showing that it ante-dates the Second World War and that these early reports showed that the Flynn effect was fully present in pre-school children, did not increase during the school age years, and was greater for non-verbal abilities than for verbal abilities. He suggests that only increases in nutrition are the likely long term causes of the effect.

William Shiu; Alexander Beaujean; Olev Must; Jan te Nijenhuis; and Aasa Must use item response theory to delve into the Estonian version of the Yerkes 1919 National Intelligence Test given in Estonia in 1934 and again in 2006 and find that, using only the invariant (stable) items there was a Flynn effect on all but one subtest. There was much variability in the strength of the effect, ranging from an effect size of 0.24 (3.60 IQ points) to 1.05 (15.75 IQ points). There was a decrease in variability across time for all subtests, although only two showed a large decrease. Overall, this suggests a real Flynn effect in this country.

Olev Must and Aasa Must continue the Estonian story by looking at guessing behaviour, and find that in some subtests of the Estonian National Intelligence test over the same period 1934 to 2006, adjustments for false-positive answers reduced the rise in test scores. Rapid guessing has risen over time and influenced test scores more strongly over the years. The FE is partly explained by changes in test-taking behaviour over time.

Jakob Pietschnig, Ulrich Tran and Martin Voracek use a different data set, the vocabulary test taken by German speaking psychiatric patients in Vienna in the 17 years between 1978 and 1994 and find that both classical test theory and item response theory indicate a Flynn effect. They also find that the Flynn effect is due to decreasing IQ variability (seen in quite a few data sets) and that increased guessing behaviour may conceivably play an additional role for IQ gains.

Jan te Nijenhuis and Henk van der Flier conduct a psychometric meta-analysis based on a large totalN = 16,663 and show that after corrections for several statistical artefacts there is an estimated true correlation of − .38 between g loadings of tests and secular score gains. This suggests that the Flynn effect is not on g. Notably, all the variance between the studies is explained by four statistical artefacts, namely sampling error, reliability of the g vector, reliability of the d vector, and restriction of range. Moderator variables were not found in these studies, but might conceivably be found in further studies.

Gerhard Meisenberg and Michael Woodley look at TIMSS and PISA results to assess international scholastic achievements at age 15 and find that lower scoring countries are gaining on higher scoring countries, suggesting on-going Flynn effects in lower-scoring countries. They point out that the closing of this gap, whilst welcome, suggests that there are biological limits to human intelligence. These limits are being approached in (most of) the higher scoring countries, where achievements are stagnating, but not yet in (most of) the lower scoring countries where achievements are rising. Therefore the kinds of environmental improvement that have fuelled Flynn effects in the recent past are predicted to show diminishing returns in the high-scoring but not the low-scoring countries. On PISA, on current trends the differences between high-scoring and low-scoring countries will converge in only 40 years, whilst on the maths and science TIMSS test, complete convergence would result after 341 years. Convergence is not guaranteed.

Edward Dutton and Richard Lynn have looked at Finnish recruits between 1988 and 2008 and found that intelligence test results for Shapes rose and then dropped very slightly, whilst both Words and Numbers showed early gains but subsequently have fallen more significantly. The end result is that from about 1997 there is a “negative” Flynn effect. It is hard to explain this drop, but dysgenic fertility is possibly part of the picture.

Heiner Rindermann and James Thompson (final editing by Doug Detterman) have looked at the NAEP data in the U.S. from 1970 to 2008 and find that the Flynn effect continues and that racial gaps have closed to some degree. However, the effects are smallest at precisely the ages which matter most, namely among 17 year olds about to enter the workplace or further education. Again, results show less variance. Students are becoming homogenous. The benefits of gap closing policies are mitigated by demographic changes.

Michael Woodley, Aurelio Figueredo, Sacha Brown, and Kari Ross do not lack ambition. They have proposed a larger theory within which the Flynn effect sits, namely that slower life histories lead to more specialised cognitive skills, and these in turn are more weakly integrated. They have established a measure of life history speed, and find correlations with some measures of intellect which are small but intriguing, and may lead to further investigation and replication.

Michael Woodley, Jan te Nijenhuis and Reagan Murphy have stepped outside the usual IQ findings and have looked at reaction time, one of the basal correlates of intelligence. If intelligence really has been rising for over a century, then one would expect reactions to stimuli to have speeded up. However, their meta-analysis of simple reaction times since 1884 finds that contemporary reaction times are slower. This is a puzzling result, and although there are always issues about early instrumentation, it is hard to see how those instruments would have been speedier to record responses. They suggest that a portion of the slowing down might be due to dysgenic effects.

In deference to ostensive definition and with gratitude for his own contributions to the field, I have invited Jim Flynn to have the final word at the close of the special issue, and give his reflections on the effect which now bears his name.

Copyright © 2013 Elsevier Inc. All rights reserved.

Breast is best, but for IQ as well?


If there was something really wrong with breast milk, we would not have survived so far. We have about 4 million years of data on efficacy. However, modern life gives us options, and formula feed is one such option, hence the plethora of studies trying to determine whether breast or bottle are better in some way, including the development of intelligence.

After many years of claim and counter-claim I believed that the field had settled down. There was no effect on the child’s IQ once you had controlled for the mother’s IQ. Received wisdom was that intelligent mothers breastfed their children, but it was the genes already in them that boosted their intellects, not their mother’s milk.

Now a new study seems to suggest that breastfeeding has an independent additive effect, even after controlling for maternal variables.

Belfort et al. Infant Feeding and Childhood Cognition at Ages 3 and 7 YearsEffects of Breastfeeding Duration and Exclusivity. ONLINE FIRST JAMA Pediatr. 2013;():-. doi:10.1001/jamapediatrics.2013.455.

The authors say that once they have adjusted for socio-demographics, maternal intelligence, and home environment in linear regression, longer breastfeeding duration was associated with higher Peabody Picture Vocabulary Test score at age 3 years (0.21; 95% CI, 0.03-0.38 points per month breastfed) and with higher intelligence on the Kaufman Brief Intelligence Test at age 7 years (0.35; 0.16-0.53 verbal points per month breastfed; and 0.29; 0.05-0.54 nonverbal points per month breastfed). Breastfeeding duration was not associated with Wide Range Assessment of Memory and Learning scores. Beneficial effects of breastfeeding on the Wide Range Assessment of Visual Motor Abilities at age 3 years seemed greater for women who consumed 2 or more servings of fish per week (0.24; 0.00-0.47 points per month breastfed) compared with less than 2 servings of fish per week (−0.01; −0.22 to 0.20 points per month breastfed) (P = .16 for interaction).

As you can see, not only are breasts in the equation, but fish as well. You may remember my earlier dictum that researchers should discuss one thing at a time, scholars two things at a time, and only outstanding scientists should attempt three things at a time. Fish is good for the brain, so fishmongers say, but this is no reason to drag it in.

An eagle-eyed reader, Stuart Ritchie, points out that some of the lower ranges of the confidence limits are rather low, and this all becomes clear in Table 1, in which model 2, which includes the demographic variables, leads to a halving of the effect, and low confidence as judged from the bottom of the range, which is almost zero.


Seems like intelligent mums are a big part of the effect, and we are very possibly close to noise when that is factored out. To give the authors their due, they try to control for the fact that many of the lower ability mothers were lost to the complete data set. If only human subjects understood precisely how important behavioural science research is, they would be as gloriously in favour of official surveys as the are in North Korea. Anyway, the paper presents data suggesting that breastfeeding has an effect on intelligence, but it is not an overwhelming finding.

A wider perspective, almost amounting to a meta-analysis comes from Brion et al.

Int J Epidemiol. 2011 June; 40(3): 670–680. Published online 2011 February 24. doi:  10.1093/ije/dyr020

PMCID: PMC3147072

What are the causal effects of breastfeeding on IQ, obesity and blood pressure? Evidence from comparing high-income with middle-income cohorts

They compared Bristol, England with Pelotas, Brazil. They deserve a medal for this comparison alone. Pelotas is in Rio Grande do Sul just above Uruguay, and I mean no disrespect to its citizens and to my school friends who live there when I say that it is more flown over than flown into. The authors found that in wealthy Bristol higher socio-economic position was strongly associated with breastfeeding but not in poorer and probably more cheerful Pelotas. In Bristol breastfeeding was associated with lower BP, lower BMI and higher IQ, adjusted for confounders. In contrast, in Pelotas, breastfeeding was not strongly associated with BP or BMI but was associated with higher IQ. Crucially, only 3% of these Brazilian children were not breast fed. About a third of Bristolian mothers never start breastfeeding or get discouraged in the first month. Breast is Brazilian best. For that reason the variable was entered as numbers of months of breastfeeding. Trial data supported the conclusions inferred by the cross-cohort comparisons, which provided evidence for causal effects on IQ but not for BP or BMI. These researchers conclude that breastfeeding may have causal effects on IQ. They make the key point that comparing associations between populations with differing confounding structures can be used to improve causal inference in observational studies.

They had IQ data for 614 kids. They struggled to work out comparative socio-economic rankings. Table 2 is informative, in that to my eye the key variable is clear: maternal education is more important than any of the other factors, followed by paternal education.





I think that the mother’s milk effect only shows up when you control for the mother’s and father’s intelligence effect, which is the main factor. Have a look and see what you think.

Meanwhile I will think about these insights every time I fly over Pelotas. In summary, chose your parents carefully, and advise them that breast is probably best, if only for nutritional reasons.

In only a few years all these studies will seem quaint. Current epidemiological projects will have entire genomes for each child, and we will probably have first estimates of intelligence derived from the individual variations on the genetic code. There may be nothing in breast milk except exceptionally healthy, nutritious and human-friendly milk.

Monday 29 July 2013

Carl Sagan and the Cosmos


Sometimes there are favourable conjunctions of planets.

Sitting in front of a TV in South London in 1980 I watched a guy, with a slightly odd posture, saying he was going to take us on a trip through the cosmos. I took the trip with him, courtesy of the BBC and its mission to educate even people who lived in Clapham.

Aside from his slightly awkward movements in the introductory trailer, Carl Sagan had an accomplished way with ideas. In one of the programs he worked through the Drake equation, which calculates the probability of intelligent life elsewhere in the universe. Broadly, it looks for planets in a habitable “goldilocks” zone neither too near nor too far from the sun, but just right for the creation of life and subsequent civilization. Sagan added a wry correction factor to the equation, a sizeable reduction for those civilizations which did not survive “their technological adolescence”. As a proto-typical anti-nuclear campaigner in South London I smiled wryly at this phrase, and became one of Carl Sagan’s many fans. There were 500 million of them, so being a fan involved no great perspicacity on my part.

As an anti-nuclear psychologist I had nothing to offer as regards the cosmos, but I decided to talk the rather staid British Psychological Society into saying something on the issue of nuclear weapons. They were uncertain whether the impending destruction of civilization by nuclear war was the sort of matter on which it was appropriate to make any comment. Nonetheless, I eventually talked them into saying something, saying anything, and they invited me to write a “statement” about it, which in 1984 became a book which they endorsed: “Psychological Aspects of Nuclear War”. An odd title, if you consider it, because if we get a nuclear war the psychological aspects will be the very least of it.

As a consequence of taking on this task I called on many scientists to help me with references, and began to get invited to conferences. Eventually in 1985 I was invited to a conference at the National Institute of Science in Washington. Carl Sagan was the star speaker. He had thoroughly pissed off the organizers by criticising the lighting and the projection facilities in that august lecture theatre, but gave a brilliant talk, which included a conjectural picture of the Earth as seen from space during a nuclear war, showing the continuing flash of nuclear weapons in a dark shattered planet as a consequence of nuclear submarine captains continuing to fire their nuclear weapons in accordance with their written orders, not having realised that the war and civilization itself was actually over.

Afterwards we stood on the steps of the National Institute, while citizen after citizen came up and asked him for his autograph. He attended to them all with the greatest courtesy, answered their questions and posed for their cameras. We started talking between the autograph requests, and our talk lasted about 2 hours, during which we eventually walked through Washington to our respective hotels. We discussed the anti-nuclear campaign, the current international political situation, my perspective as an Anglo immigrant from South America, a bit about his childhood, his views on research and politics in the US, a little bit about television and the power to convince (I had just started making much cherished TV appearances, the very first one being about nuclear war risks) and thus we covered subjects from red-shift (I had ploughed through Payne-Gaposhkin as an undergraduate) to attitude shift.

Far from this being a great man briefly condescending to help an unknown psychologist, he kept in touch with me by letter, lent me the services of his literary agent, and made sure he invited me to his lectures at the Royal Institution when he came to London, inviting me and my wife to meet him and his wife, fellow author Ann Druyan, for drinks afterwards.

Like all good communicators, Sagan was disparaged by those many scientists who find it difficult to explain themselves, and see this as a limitation of their audience, and not of themselves. When data was coming in from Pioneer they would quip at him: “Here’s little green men for you, Carl.” They forgot that good explaining requires a very good understanding, both of the problem and of the audience.

Eventually, at anti-nuclear war conferences I ended up as Carl’s understudy. The vast lecture halls would fill up with an audience eager to see the famous TV astronomer, who had been heavily trailed in the pre-conference publicity, and then his unavoidable absence would be announced, immediately followed by the unconvincing statement that the audience “was very lucky to have the London psychologist Dr James Thompson” at which announcement the hall would almost empty. I would then face the diminished and resentful audience and do my best with my psychological observations. I had only one triumph. A large number of Carl Sagan fans had lost their way to the extra large lecture hall that had been set aside for him, and arrived late. I had already launched into my psychology of nuclear war talk. Either because of the high quality of my lecture or the paralysing disappointment of having been denied their TV hero after having walked so far, they all stayed.

A good man, Carl Sagan, and a fine scientist. He had the gift of understanding, and the humility to explain himself to others with humour and patience. Fine minds can often be found in fine persons. As a consequence of his intelligence and imagination, if another planetary civilization ever finds out about us, it is very likely to be because of his brilliant insistence that Pioneer 10 and 11 should carry a gold-anodized aluminium plate inscriptions to be read by denizens of other worlds.


Odd, isn’t it, that this plaque may be the only thing that will ever be known about us: we come from the third rock from the sun; close to the 14 pulsars; please use the spin-flip hyperfine transition of hydrogen as the common unit of length and time; and this is what we look like with our opposable thumbs.

So, the most interesting question to which the answer is “Carl Sagan” is the one we are likely one day to receive from outer space:

“Hi! Who sent us the message about hydrogen?”

Sunday 28 July 2013

Words in black and white


Some words keep their utility. A  study of words and their cognates in other languages suggests that there are at least 23 “ultra-conserved” words, which are estimated to have lasted for 15,000 years. This paper by Pagel et al in Proceedings of the National Academy of Sciences, October 2012 is a notable example of the archaeology of vocabulary.

Here are the eternal words, listed by the number of language families in which they have cognates. Click here for the reference.

7 - thou
6 - I
5 - not, that, we, to give, who
4 - this, what, man/male, ye, old, mother, to hear, hand, fire, to pull, black, to flow, bark, ashes, to spit, worm

It is not the custom of this blog to offer prizes, but I have no doubt my noble readers could turn these words into a stirring message of eternal significance. “Spit in fire, thou old mother, to pull ashes, to hand bark to man, worm that we give…….”   All of human life is there. How do these words fare in modernity, by which we mean the last two centuries, beginning with the first UK Census in 1801? Yes, the opening of the Darlington Railway in 1832 was probably more significant as “the day the world took off”, but why complicate matters?

The fact that a word has survived does not mean that it is still popular. In the published English language “Thou” has become an anachronism, but “I” still retains its egotistical appeal (0.38%) ahead of the more inclusive “we” (0.15%). “Black” and the more modern “white” present an interesting picture: white pulled away from black until 1966 when black began a strong comeback, very possibly related to the “Black is Beautiful” movement. Current usage in published work puts white at 0.018% and black at 0.016%. (That graph alone is a testimony to the success of a political campaign).

So, how do these emotionally charged racial words fare in published usage? In all human enterprises one must make allowance for the “polite threshold”. In vernacular architecture, as well described by R.W.Brunskill (Vernacular Architecture, Faber, 1971) it is that stage when rough dwellings become mannered to some degree, conscious of themselves, morphing from building into architecture in the professional sense. It constitutes a deliberate obsequy to fashion, style, and an international or even classical aesthetic, rising above local convention and amateur practicality.

First, let us get rid of the small stuff. The insulting word which arouses contemporary ire and shame, deriving from the great river Niger in West Africa, has never been much used in published books (though it may have been used in everyday speech). It is at roughly the same rare level as obscene sexual words which are taboo in printed discourse.

In the 1800s three words dominated the racial sphere: negro, whites and blacks. (Pedantically, “negro” is Spanish for black and therefore mere repetition, but one assumes it was used within English in the racial sense). Negro peaks in the 1860s, and then falls into relative obscurity.

Racial is also a rare word, as is Racist (0.0006%), which despite its pejorative power does not appear till the mid 1960s, and though powerful remains relatively rare. To my surprise, neither racial prejudice nor racial discrimination show up very much. The biggest drama in usage occurs with blacks which shot up massively from the 1960s to a peak in the mid seventies, such that they were mentioned more often than whites, and that preponderance was sustained for the last three decades. A simple explanation is that Black Consciousness made it polite and even requisite to refer to coloured people in this way, though nowadays blacks and whites are mentioned equally frequently. In terms of word frequency alone, colored attained maximum advancement in the 1940s, and has declined but is still used (0.002%) as much as whites and blacks.

So, what is happening here? There is a reality which must be described, but the way in which it is done shows social and political influences, and probably polite fashions as well. Certainly, we still have Totem and Taboo, and taboo leads to euphemism and evasion. Words change in acceptability, but if there is a need to describe, a way is found.

One word makes a steady advance through the two centuries of racial group descriptions, ending up at the top of the pile. It seems to start at about 1860. It achieves more printed usage than the others, though it is hardly common (0.003%).  The word is genetic. Origin of Species was published in 1859. Ideas take time to get into discourse, and the word may not have yet achieved fixation, though it has handsomely exceeded the well-conserved ancient word “ashes”.





Disclaimer: Words may go up and down, and you may not get back the investment you made in learning them. Minor changes in word spellings and their cognates affect the results. Even allowing for that, all these analyses are highly sensitive to the scales used. If you couple words of differing frequencies in any display then you can almost draw patterns at will. It is the old “zero suppression distortion” all over again.  We are going to have to classify frequencies into readily recognisable bands, like geologic strata if we are to simplify and civilise these comparisons. Still, it is a rainy Sunday.

Friday 26 July 2013

Computable numbers, computable humans?


Does Amazon know more about you than most of your friends do? Probably much more.  Also Visa, Mastercard, eBay, Google and Prism. When doing my tax returns I found that I often visited the same petrol station at the same time of the month, putting in almost the same amount of fuel. What seemed to me a random act was known by my credit card company to be a predictable act, valuable to a hit man or a car salesman (whichever bid the higher price for the knowledge).

Despite the concerns, most of this is good news. The commercial providers can offer us exciting new books and products. (Every time I open a webpage the ads dutifully reflect my latest sales enquiries). The spooks may help us by catching evil people who are trying to blow us up. (Not using a credit card on a Friday is a dead giveaway). I am grateful. They may also catch me having dangerous thoughts. I am less grateful, and somewhat resentful. However, I will trade a little intrusion for a little more safety. Problem is, I do not know how much intrusion for how much safety.

George Dyson has written a most interesting essay in Edge, a site which generally provides a good read. The whole thing is here:

Dyson argues, with reference to Turing’s essay “On Computable Numbers” that you can never know what a system can do without running it to find out, that is, you cannot determine all the consequences of a code by analysing the code, it must be allowed to operate a bit.

Turing’s paper is readable by those like me who lack sufficient maths to understand the specific mathematical problem he was dealing with, but have sufficient knowledge of old-style programming to understand that this is the dawn of the computer age. It is charming to see him setting out how a computer would solve his problem, and much of it seems familiar, though it was being written for the first time.

At Bletchley Park I saw an exhibition about Turing which included a letter from his Sherborne schoolteacher, describing him as “one of the two brightest boys I have taught”. Given that the schoolboy Turing was able to read Einstein’s 1905 relativity paper and work out a new implication from it, one is tempted to dig up the schoolteacher’s grave, or at least his collected papers to ask “what the hell happened to the other boy?”

Dyson continues: “The ultimate goal of signals intelligence and analysis is to learn not only what is being said, and what is being done, but what is being thought. With the proliferation of search engines that directly track the links between individual human minds and the words, images, and ideas that both characterize and increasingly constitute their thoughts, this goal appears within reach at last. "But, how can the machine know what I think?" you ask. It does not need to know what you think—no more than one person ever really knows what another person thinks. A reasonable guess at what you are thinking is good enough.”

So, the Government knows lots about us, about our thoughts, and as a consequence about our likely behaviours. Big data is a boon to Big Government. They can probably spot (within the boundaries of a reasonable guess) exactly when I totally lose patience with the intrusions of an over-bearing State, and decide to take malevolent actions against them.

Dyson cautions: “Any formal system that is granted (or assumes) the absolute power to protect itself against dangerous ideas will of necessity also be defensive against original and creative thoughts.”

He argues that there is nothing wrong with a State trying to protect its citizens, except the very fact of not being honest about it. He commends the UK for having many public surveillance cameras, but open discussion about them, and a legal framework determining how they can be utilised.

Dyson does not mention that this Mephistophelian bargain (high security to protect secrets reduces the freedom to communicate ideas) was rejected by Edward Teller, the “father” of the H bomb, who said that the cost of security was always too high, and the the US should drop all secrecy, including nuclear weapons secrets, and make everything known, because the explosion of talent would ensure that it was always well ahead of closed, secretive regimes. (Like many others, I think Teller knifed Oppenheimer in the back on the issue of his security clearance, but a good idea is a good idea, whoever propounds it).

Anyway, I hope these summer thoughts get read by a Government official somewhere, who will thus change my classification from “Harmless” to “Relatively Harmless”.

Thursday 25 July 2013

Wisdom and judgment, where did they go?


Hard to tell what makes a word unfashionable. Words are tools. A well formed word carves ambiguity at the joint, reduces uncertainty to a minimum, makes meaning as clear as a pane of glass. Why would one ever lay a word down, unless a very much better one presents itself?

Equality has retained its utility unchanged for two centuries. Ability as we have already seen has gained in popularity: perhaps a fanfare for the common man, a democratically acceptable version of “clever”.

Two words stood high and proud in 1800 judgment and wisdom. They have been in gradual decline ever since. Ability surpassed wisdom by 1907, and surpassed judgment by 1937.

Perhaps we should not read too much into this. Seems odd, though. It might account for us being more vulnerable to long cycle risky events, like bank failures, financial crashes, credit crunches, that sort of thing. Just a hypothesis.

Disorders of the brain, and the metric shift illusion


Did you realise that if everyone in the UK switched off just one light bulb we could close down an entire power station? Think of the savings we could make!

Or, to put it another way, if we were to reduce our domestic electricity consumption by turning off a light bulb, thus bringing about a 0.5% reduction in demand we might be able to reduce national standby power generation by 0.5%  which is equivalent to shutting down one out of two hundred power stations. Somehow, it is less impressive that way, isn’t it?

This is what I call the Metric Shift Illusion. You convert from one basis of measurement to another, in order to impress your audience. Virtually every grant proposal begins with the phrase: “XXX thousand people suffer from Condition YYYY at a cost of ZZZZ billions”.

The Wellcome Trust, no less, source of succor to destitute academics, has used this ploy in a Press Release:

A new report estimates that disorders of the brain cost the UK almost £113 billion per year, more than the GDP of New Zealand.

This is supposed to make you go “Wow! Big problem. These people need funding”. New Zealand is an entire country (and a very scenic and pleasant one, I am reliably told) so presumably the problem, brain disorders, is the size of that whole country, or something like it, and particularly deserving of our attention.

“The cost of brain disorders is 3126 Euros per person per year” is less stirring, though more informative, if we are sure it is accurate.

However, when you read the paper, the whole confection falls apart. Rather than “brain disorders” being tumours, abscesses and the like, they have thrown in age-related dementias and psychiatric disorders, such that their top 5 disorders are: headache, anxiety disorders, sleep disorders, mood disorders and somatoform disorders. I am all for recognising that we need to understand the brain, but I think this is pushing things a bit far. Headaches? There is usually little to be seen on a scan, and most of the treatments have a large psychological component. Anxiety disorders? Again, a very large psychological component. This is a very loose and inclusive re-definition of brain disorders.

The authors are explicit as to how they reached their total numbers: “a prevalence-based approach which multiplied the total number of UK persons affected by a disorder in a 12-month period (2010), with their mean cost in the same year”. A little later they confess: “the total amounted to roughly 45 million diagnosed cases, ranging between 26,000 cases of brain tumour and 18 million cases of headache”. So, this paper is a study of headaches and anxiety, and some other stuff. Does the Trade Descriptions Act apply to the titles of papers?


The crux of this paper is to understand how they calculated costs.

“Indirect costs associated with patients’ productivity losses constituted by far the largest component of the total cost comprising 46.4% of the overall cost, whereas the remainder of the cost was divided into 26.8% each for direct non-medical and direct healthcare costs.” So, what assumptions did they make in calculating productivity losses? Were they age corrected? Did they assume that the stated reasons for absence from work could be trusted? Did they assume that people at work are actually working? These are tricky matters, with much scope for approximations and rough assumptions. Commonly, staff reductions lead to increased productivity.


Figure 3 suggests the costly disorders are Dementia, mood disorders, psychosis, addiction and anxiety disorders. This certainly seems likely. My gripe is about the calculation of indirect costs. To give the authors their due, they have not added any in the case of dementia, mental retardation, and child disorders. The calculation of non-medical and implied social costs is difficult, and much affected by current economic realities. The only expensive “loss of production” disorders are those which affect irreplaceable key workers, and there are few of those. For many disorders there are only too many people willing to step in to take the job. Much more detail about the assumptions would have made the whole paper more convincing. (This applies not just to this paper, but to the general methodology of indirect costs). The whole point of open economies is that they are elastic. It is easy to find substitutes (either persons or products) for most requirements. Any loss of health in executives over 40 leads to faster promotion for executives under 40. When one mobile phone company goes down the other takes over their market share. And so on.

However, if we concentrate on direct healthcare costs, anxiety, strokes, addiction, psychosis and mental retardation are particularly expensive to treat.

The paper has interesting material, but New Zealand was best left out of it.


Some Other Popular Metric Shift Illusions

“If we were to increase income tax by just one penny, we would have billions to spend on infrastructure/sick donkeys/apprentices/invading foreign countries/stimulating the economy”. This last example is particularly silly, because a penny drawn from the productive economy is a certain loss, and the other schemes are uncertain gains, of equal magnitude at best, commonly much less.

“If everyone on earth held their breath for 10 seconds, think of the tons and tons of oxygen we could save. And if only we could get everyone on earth to hold their breath for 10 minutes………..”

By the way, don’t turn off your lamp bulb. For a very small cost you can avoid falling down stairs. People falling downstairs cost us billions and billions and billions.

Wednesday 24 July 2013

Fall in intelligence, rise in ability


The recent heat wave in London is probably responsible for a certain lassitude of the intellect, but it has led me into idle speculation: what popular words are used to denote cleverness? The absolute frequency, and the historical trend from 1800 might prove informative.

First, we can get rid of the abbreviation IQ. It does not show up at all until the early 1920s and by 1930 almost disappears again, only to make a very slow return which peaks in the mid 1970s and then subsides somewhat. It is rare, so forget about it.

Smart is somewhat more frequent, and stays remarkably stable, rising somewhat in the last decade. Still pretty rare.

Clever rose from nowhere to a respectable peak in 1900 and then declined to the end of the millennium, with a little bit of a revival since. Still pretty rare.

Intelligent was more frequent, but has been in relative decline since the 1930s, ending up no more popular that the rare words we have already discarded above.

Bright boomed in the 1870s, and then declined, but still has respectable usage.

One word has flourished, surpassing all others by 1930 and zooming upwards ever since.


Thus, we can see that there has been a drop in smartness, cleverness, and intelligence. There has been tolerance of brightness. There has been warm acceptance of ability.

What’s your ability quotient?




This note was posted on a hot and humid evening. Slightly different variants of the keyword might have give different results. No animals were harmed in the conduct of this experiment.

Tuesday 23 July 2013

Impact factors, and Sherrington re-visited


The brain is waking and with it the mind is returning. It is as if the Milky Way entered upon some cosmic dance. Swiftly the head mass becomes an enchanted loom where millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of sub-patterns.”

This is Charles Sherrington’s description of a person waking up, as seen from the perspective of brain activity. Writing in 1942 he used an already ancient image, that of the 1801 punch-card programmed Jacquard weaving loom.  He may also have been influenced by an 1887 paper by the psychologist Fredric Myers, who asked his readers to "picture the human brain as a vast manufactory, in which thousands of looms, of complex and differing patterns, are habitually at work".

Sherrington obviously had not seen an Enigma coding machine, though early commercial versions were available in the 1930’s, and because of war time secrecy had no idea that Bletchley Park was working on the construction of mechanical code-breaking Bombes. Colossus, the first electronic brain, was available at the end of the following year, though that was kept secret for almost 30 years.

All that is probably just as well, because his brilliant metaphor has stuck. While I was still a researcher into the effects of cortical injuries sustained in childhood I found his enchanted loom fanciful, but it catches the reality of myriads of impulses flashing along pathways. The phrase has gained currency because it has been used as the title for neuroscience books, so we know it had some impact.

Impact factors, on the other hand, are baleful gifts. Of course some publications are better than others, and some journals are far better than others, so the calculation of impact is understandable. But once there is an index there is an incentive to game the system. The Spanish proverb says “Once the law is made the loophole will be made”. So, publications become crafted for the requirements of the system, not for scholarly purposes. This leads to countless iterations of the same tired database, so that each mini paper requires readers to wait for the next instalment, each of which boost publication rates. Perhaps this is inevitable in what remains, at heart, a cottage industry. If papers had to be anonymous until they reached a certain level of citations it might cut out a lot of noise.

However, the main reason to quote Sherrington is to show that there are other ways of making an impact. His prose is a delight, and that cannot be said of many scholarly publications today. We are cabined, cribbed, confined, bound in To saucy doubts and fears, as we strip our writing of anything which might show enthusiasm, flair and individuality. Dispassion rules. We have Editors to assuage.

All power to those researchers who can make an impact on our imaginations.

Monday 22 July 2013

Intelligence of 5 year olds in the UK


Birth samples are usually the best, because they define a population exactly. There should be no biases in the sample. However, unless one is willing to pursue them to the ends of the earth, as the children grow up they tend to get lost to researchers. Families move, break up, forget to answer letters, and generally drift off in their own very human way. This is particularly the case for those who don’t have much of an interest in scientific surveys, which after all pay them nothing, and rarely have anything interesting to report for many years. Taking part in a longitudinal survey is an almost perfect measure of delayed gratification, and appeals to higher intelligence, conscientious families.

So it is a pleasure to report on a study which has done its very best with the available data on the intelligence of 5 year olds. Although quite a lot of the probably less able subjects dropped out of the study, the authors have made the best of what data they have available, despite selective fall-out. The best is the best, and better than none. We must be Bayesians in the real world, rather than dreaming of data perfection.,

Recent data for majority and racial minority differences in intelligence of 5 year olds in the United Kingdom

Richard Lynn and Helen Cheng looked at the UK Millenium Cohort Study of 14,379 5 year old British children. The study began with 19,000 babies born in September and August 2001 and over-sampled ethnic minorities. 79% made it to the 5 year stage, when they were tested with the British Ability Scale. Parental education, roughly measured, correlated .31 with children’s IQs, and .38 for maternal education and child IQ for the non-whites.

The sampling is somewhat complicated, because in searching for poor, disadvantaged children they over-sampled poor wards, and so the figures do not directly match population statistics. There are advantaged wards, disadvantaged wards and ethnic wards. The eyes glaze. Laudable aims, but confusing for the researcher looking for general trends. I thought they had got 72% of the advantaged subjects, 66% of the disadvantaged and 61% of the ethnic subjects, but the next table suggested that calculation was wrong. You try reading the technical paper on sampling and see if you can pin down exactly how they went about their business.

Advantage or disadvantage makes no difference to household size at 3.9 persons, but ethnic households at 4.8 persons seem to have an extra child.

The results are interesting, but the numbers in the ethnic minorities do not correspond to the proportions of ethnic numbers in the population in 2001. This suggests that the selective fall-out has been considerable, and has varied between different ethnic groups. Unless the actual fall-out rate is known, little reliance can be placed on the figures, other than to say that participating children are probably more educated than average.

At a glance, even allowing for selective fall-out, the results are roughly in line with other school and population surveys, but the differences are often smaller, probably because of sampling.  

IQs of 5 year olds in the United Kingdom in the Millennium Cohort Study
















− .08






− .27






− 1.04






− 1.02


Black Caribbean




− .29


Black African




− .74


Other Black




− .61


Other Asian




− .46








Other ethnic




− .53







Competition in the womb


I am in favour of competition. Not all school essays are of equal standard. One of my great pleasures in early life was to be asked to read out my essay to the class. Normally the accolade went to Keith Yorston or Michael Turner, but I relished my occasional turn, accepted the competition, and felt spurred on to greater literary feats. We were happy and well-fed children living in a little country where there was no television. Even a short essay constituted entertainment.

Competition in the womb is another matter. In the essay reading competition no-one was hurt. Egos, perhaps, but egos improve once they have been knocked back a bit. The untrammeled ego is a social menace.

When two twins must battle for access to scarce nutrients in their mother’s womb then competition takes on a harsh significance. For most of the 20th Century the results were very clear: twins in general were 5 IQ points behind singletons or, to put it another way, they were a third of a standard deviation behind in terms of intelligence. On average, singletons would expect to be at the 5oth percentile and twins at the 37th percentile. A significant difference in the pecking order.

This savage difference was maintained despite controlling for social class, but not dependably maintained when controlling for lower birth-weight and shorter gestation. So, during the last century twins got short commons, poor rations, thin gruel and a bad deal. Evolution is unfair, and it doesn’t even know it is unfair. Stuff happens and organisms evolve.

In more recent times the Deary Edinburgh gang have taken another look at this issue, as well they might. They have collared the largest ever sample of UK schoolchildren, and compared their intelligence at age 11 against their scholastic achievements at age 16. Correlation is not always causation, but it would be bloody unlikely if every correlation was a coincidence. As a clue, when one measure precedes another, it ups its likelihood of being the cause of the other. Anyway, those scholastic results deserve another later post, if only to discomfort those educationalists who ignore human intelligence.

In this particular paper (see reference below) the cognitive ability scores of 178,599 schoolchildren in England (average age about 11 years) were looked at in terms of twin or singleton status. There were no significant discrepancies between twins or singletons. Not only was there no difference in intelligence, which is the cause of most variation in scholastic achievement, but there were no differences in later scholastic attainments.

This is an interesting paper to look back upon when one expectantly savours the prospect of the special issue of Intelligence on the Flynn effect, due out in December. It certainly boosts the argument that the apparent secular rise in intelligence must be linked to better nutrition and health care and general living circumstances. The fact that we can now raise twins without them being behind singletons in terms of intelligence strongly suggests that we are boosting outcomes by making pregnancy much less costly for both mother and children, to the benefit of their intellects.

There is no longer a cognitive cost to being a twin. We have assured twins a well-nourished start in life.  They may never get to read out their essays to their class mates. But they can stand in line with other children, and do their very best to get chosen for the life tasks ahead.



Is there still a cognitive cost of being a twin in the UK? Calvin, Fernandes, Smith, Visscher and Deary Intelligence 37 (2009) 243–248

Thursday 18 July 2013

The enchanted loom


Brains present a problem of scale. How small does one have to go to understand what is going on? 20 micrometres? 25 nanometres? A question of this sort generates a behaviour known as “a furtive wiki peek”.  A micro metre is a millionth of a meter, a nanometre a billionth of metre. Therefore there are 1000 nanometres in a micrometre. A metre is a metal bar in Paris, probably France’s last remaining intellectual asset.

The deeper you dig into brain the higher the mountain of data you throw up behind you. Worse, you are not just mapping a dead city: your main interest is recording all the traffic, the cars, pedestrian flows, telephone messages, emails, and conversations in the street, perhaps even glances. Lots of data. Mounds of it. Terabytes. Yottabytes. Ok, start with the familiar kilobyte, which has 1000 bytes (1024 in binary, but we will keep things simple because it is very hot in London). Then megabytes 10002  giga 10003   tera  10006     and so on upwards to yotta 10008 . This much data will take time to crunch.

How do you record what is going on? Probe with a sharp needle? Slice and stain the brain? These musings are triggered by Alison Abbott, who has done a great job reviewing recent developments in brain research in  Nature.

She arranges her thoughts into three headings: measuring, mapping and understanding.

Measuring one neurone with a probe was cutting edge stuff in the 1970. I can remember watching the Cambridge Psychology demonstrations with awe. Now a probe can record a couple of hundred neurones simultaneously. The new upcoming silicon probes have 52 thin wires leading to 456 silicon electrodes, and can record from all layers of the brain simultaneously.

Mapping brain activity has usually been done by slicing the brain as thinly as possible, staining the slices to render the cells visible, and looking at them under a light microscope. Putting the slices together into a 3 dimensional model is not trivial. Researchers took a decade to slice a brain into 7,400 layers 20 micrometres thick, and then spent 1000 hours on two super-computers to piece together the terabyte of data (finally, we have a reference measure). This revealed folds in the brain usually lost in two-dimensional cross sections. Researchers now want to push on to 25 nanometres (one-thousandth of the thickness of an average cell). At that resolution you see “every damn little thing”. Yet another reference measure.

Understanding what the brain is doing is the most daunting part. One cubic millimetre of brain tissue, using the newest techniques, will generate 2,000 terabytes of data. A human brain would generate 200 exabytes. ( 10006). This is a lot to handle. 30 seconds of brain activity will generate more data than everything sent back by the Hubble telescope.

At the moment, we are not all that well-placed to understand how the brain does the things it does. So, when you hear about the relationship between brain and behaviour, and between brain regions and intelligence, please understand that we are not yet at 25 nanometres, either in measuring, mapping or understanding.

Wednesday 17 July 2013

Creativity and technical innovation


I have kept my creativity to myself, but others are more generous. They publish papers, register patents, and generally exert themselves in public. What skills are required in order to be really creative?

“One reason creativity and innovation are difficult to
study longitudinally is that few people in the general
population create products deemed creative and innovative
by experts. Because of low base rates, large samples
are needed to generate findings with statistical stability
and real-world generalizability, especially given how
many different ways there are to develop products that
experts evaluate as creative.”

Readers of this blog will have already come across the Kell, Benbow and Lubinski gang, whose Study of Mathematically Precocious Youth longitudinal project is currently tracking 5 cohorts amounting to over 5,000 intellectually talented individuals throughout their lifespan.

Lubinski, D., & Benbow, C. P. (2006). Study of Mathematically Precocious Youth after 35 years: Uncovering antecedents for the development of math-science expertise. Perspectives on Psychological Science, 1, 316-345. View in PDF

Table 1 on page 319 of that paper gives the overall structure of their study, which shows a dedication to longitudinal studies normally restricted to Norwegians living in sunless fiords.

Now Kell, Lubinski, Benbow and Steiger are at it again. In this particular paper they are working on the 563 intellectually talented 13-year-olds (identified by the SAT as in the top 0.5% of ability) tested in the 1970s.

Creativity and Technical Innovation : Spatial Ability's Unique Role” Psychological Science published online 11 July 2013

DOI: 10.1177/0956797613478615

In this new paper they make a simple but powerful argument. If you do not  measure spatial ability you are missing out on a powerful predictor of later achievement, particularly as regards creativity and technical innovation.

This is no news to those of us who have been following their work for years. Of course you need to cover the major features of intelligence, in the way that the Wechsler face to face tests have always done.

Lubinki et al. have been publishing about all this for years. This is because, in addition to the US Scholastic Assessment Test (which does not test spatial ability) a spatial-ability composite score was calculated by equally weighting and summing scores on two Differential Aptitude Test subtests: Mechanical Reasoning and Space Relations. Composites such as these “tap a basic ability in spatial visualization”
(Carroll, 1993, p. 324).

The sample of 393 males and 170 females was 69% Caucasian, 6% Asian or Pacific Islander, 1% African American, and 1% other (23% of participants did not report their race-ethnicity).

So, what the authors are showing the general public, once again, is that if you were to add a spatial component to the U.S. SAT tests, then you would be able to find more bright young students with creative and patentable ideas. 

A two-step discriminant-function analysis revealed that the SAT subtests jointly accounted for 10.8% of the variance among these outcomes (p < .01); when
spatial ability was added, an additional 7.6% was accounted for—a statistically significant increase (p < .01). The findings indicate that spatial ability has a unique role in the development of creativity, beyond the roles played by the abilities traditionally measured in educational selection, counselling, and industrial-organizational psychology. Spatial ability plays a key and unique role in structuring many important psychological phenomena and should be examined more broadly across the applied and basic psychological sciences.

Here is a snapshot of their 2009 findings, showing the rate at which these young people went on to get higher degrees, and in which subjects. V S and M stand for Verbal, Spatial and Mathematical. (Maths still looks a pretty good predictor). Draw your own conclusions about the levels of intellect required in each discipline.


Wai, J., Lubinski, D., & Benbow, C. P. (2009). Spatial ability for STEM domains: Aligning over fifty years of cumulative psychological knowledge solidifies its importance. Journal of Educational Psychology, 101, 817-835. View in PDF

Few things illustrate the vast chasm between the popular (mis)understanding about IQ and the work being done by psychometric researchers than does this paper: to researchers this is a finding which has been well-known since 2006, if not far earlier.  It is obvious that one should test a broad range of intellectual abilities in order to identify and nurture the brightest minds. Bright minds improve economies and societies.

To the general public (or their appointed representatives) the additional test represents a dangerous idea. Spatial abilities are higher in males. There is also a significant difference between genetic groups. The results of the verbal and mathematical tests are already “wrong” (too many males, too few racial minorities). Why add a further test which gives the “wrong” answer, even if it might help us find the brightest citizens?

Tuesday 16 July 2013

Nature, nurture and expertise


It takes a certain self confidence to publish a paper with a four word title, particularly when those four words include “nature” and “nurture”.  The paper has four authors, so presumably they were allowed to chose a word each. On the other hand, a paper entitled: “Analysis of reading comprehension in monozygotic and dizygotic twins, distinguishing between the most competent 5% and the less competent 95%” would lack rhetorical flourish. It would also have sold the paper short, for the authors have done more than just report a result: they have explained many of the debates surrounding genetic research in a clear and helpful manner. They have demonstrated expertise as scholars, and patience as explainers.

Robert Plomin, Nicholas Shakeshaft, Andrew McMillan and Maciej Trzaskowski all work at the Institute of Psychiatry, a Camberwell institution of uncertain architecture, where they have been tracking twins for many years. They still have over 10,000 twins taking their tests, including four different reading tests. For those of you in a hurry, the answers are as follows: More than half of the difference between expert and normal readers is genetic. Expert readers show the same genetic effects as normal readers. Less than a fifth of the expert-normal difference is due to shared environment.

So, you can clock this one up as yet another paper showing that genetics rule. And so they, very probably, do, given certain favourable circumstances.

The authors are primarily interested in the origins of expertise as it exists in the world (“what is”) rather than investigating the extent to which training can improve performance under experimental conditions (“what could be”). “We used the twin method to investigate the genetic and environmental origins of exceptional performance in reading, a skill that is a major focus of educational training in the early school years. Selecting “reading experts” as the top 5% from a sample of 10,000 12-year-old twins (1931 monozygotic pairs, 1714 same-sex dizygotic, and 1668 opposite-sex dizygotic) assessed on a battery of reading tests, here are the three main findings in a little more detail. First, they found that genetic factors account for more than half of the difference in performance between expert and normal readers. Second, their results suggest that reading expertise is the quantitative extreme of the same genetic and environmental factors that affect reading performance for normal readers. Third, growing up in the same family and attending the same schools account for less than a fifth of the difference between expert and normal readers.”

As regards the old style nature and nurture debate about expertise, the authors have found two extreme environmentalists, Ericsson and Howe, but no extreme hereditarians. “In all areas of the behavioral sciences, genetic influence has been shown to account for substantial variance, but this same research provides strong evidence for the importance of environment as well. Heritability, which is an effect size index of the proportion of phenotypic variance that is accounted for by genetic variance, is typically between 30 and 60% across psychological traits, which means that 40–70% of the variance is not genetic in origin”.

“The critical point is this: There is no necessary connection between ‘what is’ and ‘what could be’. That is, even if the difference between experts' performance and the performance of the rest of the population were due solely to genetic differences (what is), a new environmental intervention such as a new training regime could still greatly improve performance (what could be). For example, although obesity is highly heritable, if people stop eating they will lose weight; moreover, a novel environmental intervention such as bariatric surgery can dramatically reduce extreme obesity.”

Of course, this is not an entirely convincing example, because bariatric surgery can fail if, as often happens, patients circumvent it by changing to smaller but far more frequent meals, but the point still has potential. Personally, I think they are being too kind to putative new training regimes, because so few of them ever amount to much when compared with ordinary training regimes. Reading schemes are a dime a dozen: the have to be used quickly before their special effects wear out.

They continue: “Showing that diets and other interventions can make a difference (what could be) tells us nothing about the genetic and environmental origins of obesity as it exists in the world (what is). In the same way, finding that training improves performance (what could be) tells us nothing about the genetic and environmental etiology of existing performance differences in the population (what is). Although there is no necessary relationship between ‘what is’ and ‘what could be’, some of the most far-reaching questions about the acquisition of expertise lie at the interface between ‘what is’ and ‘what could be’. “

Plomin has always argued that it would be wrong to talk about genetic influence in terms of genetic constraints: new circumstances or new methods of instruction may change the picture considerably or, at the very least, it is conceivable that they could.

“Heritability is a descriptive statistic that describes the average extent to which genetic differences (i.e., differences in DNA sequence) between individuals account for phenotypic differences on a particular measure in a particular sample with its particular mix of genetic and environmental influences at a particular developmental age and secular time. In other words, heritability describes ‘what is’ in a particular sample; it does not connote innateness or immutability. Nor does it indicate the mechanisms by which DNA differences affect individual differences in performance. By itself, DNA cannot do anything — it requires an environment inside and outside the body to have its effects. Access to experience and practice is one of the many pathways between genes and behavior.”

“The surprise from research using genetically sensitive designs in many domains is that shared environmental effects are so small”

Personally, I think this is a very important point, and damages the Mark I environmentalist position, which has always laid stress on the presumed shared advantage conferred by family and school.

What is inherited is DNA sequence variation. The DNA sequence in the single cell with which your life began is the same DNA sequence in all of the trillions of cells in your body for the rest of your life. Nothing changes your DNA sequence variation — not environment, biology or behavior. What changes is the rate of transcription of your DNA sequence into RNA. For example, you are changing the transcription of your DNA that codes for neurotransmitters as you read this sentence. If your inherited DNA sequence coding for one of these neurotransmitters differs functionally from other individuals, this coding difference will appear every time that your DNA is transcribed into RNA — as you read, think and practice. Transcription of DNA into RNA is a response to the environment; what is inherited is DNA sequence variation. All of the other -omics in between genomics and behavior – epigenomics, transcriptomics, proteomics – are important for understanding pathways between genes and individual differences in outcomes, but they are not inherited from parent to offspring. For this reason, DNA sequence variation is in a causal class of its own in the sense that there is no direction of effects issue when it comes to correlations between genes and behavior. In other words, correlations between DNA sequence variation and behavior are ultimately causal from genes to behavior because our behavior and experiences do not change DNA sequence variation. Other correlations between behavior and biology, including all the -omics and the brain, raise questions about the direction of effects, that is, whether the correlation is caused by the effects of behavior on biology or vice versa.”

The authors also report on the work of Fox, Hershberger and Bouchard, 1996 who used a twin design to look at training effects on a motor learning task. All the twins improved, rising from 15% on target to 60% on target, some twins improved more than others, and there was a genetic influence on the outcome of training, such that the estimated heritability seemed to have risen by the end of training.

If we can ever attain the ideal of “a level playing field” in life then we will be able to see who can really run faster (and the proportion of variance accounted for by genetic influences will very probably increase, not decrease because the good environment will apparently fall out of the equation).

Life events. “Life events have been used as environmental measures in thousands of studies, but life events are not measures of an objective environment ‘out there’ that happens passively to people. The likelihood that we will experience problems with relationships, financial disruption, and other life events – and nearly all other environmental measures used in psychological research – depends in part on genetically influenced behavioral traits (McAdams, Gregory, & Eley, 2013). A review of 55 independent genetic studies using environmental measures found an average heritability of 27% across 35 different environmental measures (Kendler & Baker, 2007). There are few measures of psychologically relevant environments that do not show genetic influence when investigated in adequately powered genetically sensitive studies; significant genetic influence has been reported for some unlikely experiences such as childhood accidents (Phillips & Matheny, 1995), bullying victimization (Bowes et al., 2013), and children's television viewing (Plomin, Corley, DeFries, & Fulker, 1990).

Genotype-phenotype correlation. “Consider the development of expertise in reading. Children who are expert readers are likely to have parents who read well and provide their children with both genes and an environment conducive to the development of reading (passive genotype–environment correlation). Children with a genetic propensity towards reading might also be picked out at school and given special opportunities (evocative type). Even if no one does anything about their reading, children with genetic proclivities towards reading can seek out their own enriched reading environments, for example, by selecting friends who like to read, or simply by reading more books (active type). We suggest that such genotype–environment correlational processes are important mechanisms by which children develop expertise in other domains as well, such as sports and music.

Specifically in relation to the development of expertise, genotype–environment correlation research leads to an active model of experience in which children select, modify, and create their own environments in part on the basis of their genetic propensities. Rather than thinking about the development of expertise as the passive acquisition of an imposed one-size-fits-all training regime, this active model of genetically guided experience leads to a more individualized approach. The essence of the active model of experience is choice — allowing children to sample an extensive menu of experiences so that they can discover their appetites as well as aptitudes. This active model of genotype–environment correlation might be more cost-effective in fostering expertise than the passive training model – and it will certainly be more fun for parents as well as children – because if all goes well, children will try to become the best they can be because they want to, not because they are made to do it.”

As Jensen said long ago, children will probably do better if offered an educational cafeteria, and not a set meal.

I have quoted this paper at length because I think it clarifies many issues. Short title, long on content.  It is a free access paper so have a look at it yourself.

Monday 15 July 2013

Intelligence, personality, and self-knowledge


It has been usual in much of the history of the psychology of individual differences to deal with intelligence and personality in different chapters. Intelligence is about abilities and skills, personality is about emotions, attitudes and behavioural preferences.

Intelligence has one main score, g, and three or four component and subsidiary scores, such as verbal, arithmetical, spatial and processing/memory. You have to take an actual test, and will eventually start to fail items that are too hard for you. No wonder these tests generate visceral reactions. Self rating of genius is not allowed: you have to prove every ability with correct answers.

Personality has five main scores: neuroticism, extraversion, openness to experience, agreeableness and conscientiousness. These were called the Big Five, and represented something of a truce between those who favoured 3 factors and those holding out for 16 factors. Science progresses, but slowly. You have to take a personality test, but you are told “There are no right or wrong items” and there is nothing to prove. This liberal approach generates far less animosity in the general public. Yet, a moments thought about living with people confirms that some are easier to get on with than others. At the very least, ticking a box which says “I don’t particularly care what happens to other people” should raise a scintilla of doubt about whether they would be an agreeable companion on a difficult journey. Some items must be “wrong” in a social sense.

Happily, this obvious point has occurred to brighter minds (Rushton and Irwing, 2011) , who have factor analysed the five factor model and shown that it can be reduced to one dimension: the General Factor of Personality. High scores on this General Factor of Personality indicate a “good” personality; low scores a “difficult” personality (someone who is hard to get along with). Individuals high on the General Factor of Personality are altruistic, agreeable, relaxed, conscientious, sociable, and open-minded, with high levels of well-being and self-esteem. Those with poorer personalities are at the other end of the descriptive spectrum. They would tend to be selfish, disagreeable, anxious, not dependable, unsociable, closed-minded or rigid thinkers, with high levels of distress and low self-esteem.

We are always at liberty to name factors as we wish, and to my mind this could also be labelled “Easy to get along with” versus “Difficult and un-cooperative”. Mind you, not everyone agrees with this simplification. I regard it as performing a public service, in that it ought to help us avoid vexatious people. 

To what extent is personality (as one factor) correlated with intelligence (as one factor)?

Before answering this question, we must note a curious feature of personality assessments: they are all based on self report. Are you a kind and good natured person? I am sure you are. However, I would be more convinced if your colleagues confirmed it privately, rather than that you asserted it on the basis of self-love and selective memory. These facts were borne in on me by many years of using the Belbin system, which seeks to find out what sorts of team roles people habitually adopt when working in groups. Individual self-perceptions were supplemented by at least 4 independent observers. I used to ask for at least 8 observers, who all sent in their observations privately to me. Self-perceptions very rarely coincided with observers’ opinions, (say only 15% of the time) and then usually only when the person concerned had a very clear team role preference. In the end, I only used observer’s assessments, and my clients preferred their feedback when seeking to understand themselves.

Self knowledge has limits. The energy we put into being ourselves reduces our capacity to monitor ourselves. Too much self-knowledge, too much of the time, might endanger our survival.

Curtis Dunkel from Western Illinois University has found a data set from Block and Block (2006) in which children’s personality was rated by assessors and intelligence was assessed concurrently. It is one of those treasure troves which permits interesting research. The sample size of 104 is pretty good bearing in mind they were followed from early childhood, and given face to face Wechsler Intelligence tests, the gold standard for intelligence assessment. Among other findings, the correlation between intelligence at 11 and 18 is an impressive 0.84

Dunkel finds that there is a significant association between intelligence and personality. Stable personality at 18 (as assessed by others) and stable g as derived from the Wechsler Adult Intelligence Test correlate at 0.46 which is substantial as well as being significant. It would seem that being brighter than average goes together with having an agreeable and conscientious attitude.

This puts the cat among the pigeons. We certainly need further studies on externally assessed personality measures, not on self-reported questionnaires, but a confirmation of this result would suggest that Dunkel is right to suggest that they point to the possibility of unification across individual differences in cognitive ability and personality under the banner of life history theory.


Curtis S. Dunkel (2013) The general factor of personality and general intelligence: Evidence for substantial association. Intelligence, In Press.

J. Philippe Rushton and Paul Irwing (2011) The General Factor of Personality: Normal and Abnormal in (Eds)  Tomas Chamorro-Premuzic, Sophie von Stumm and Adrian Furnham. Wiley-Blackwell Handbook of Individual Differences, First Edition. 2011 by Blackwell Publishing Ltd.

Wednesday 10 July 2013

More observers, fewer strange observations


It has been speculated that we live in an era which represents the apotheosis of pictorial culture, awash with images, immersed in the perspectives of perspective. Prof Jim Flynn considers this to be one possible cause of the apparent secular rise in intelligence (the Flynn effect) as countries engage in modernity. Certainly, in contrast with even a century ago, we have easy access to photographs. Books no longer boast of having “twelve black and white photographic plates”. We have got over the shock of colour photography, and expect every magazine to be full of photographs. Even the word “photograph” is falling out of usage. “Images” suffice.

We have become image-sophisticated. In retrospect, this came about by means of many technologies, but digital photography has led to a breakthrough. Almost everyone has access to a camera, and over a billion carry a camera equivalent with them at all times.

What are the consequences? First, most photo-reportage is done by people on the scene. Can you imagine bothering to send out a photographer when passers by are transmitting live feeds of the earthquake? Now we get photos of the interiors of planes moments after they have crashed. Second, it is harder to black out and ignore an event. A drunk falling to the ground and injuring himself can be ignored. Accidents happen. A policeman, in great irritation, lashing out at the drunk can be caught on camera. Factor in security cameras, and in urban settings we are on camera much of the time. On balance, it might be a good thing.

Now draws attention to another phenomenon:

settled no bigfoot


I assume this general observation should hold true of the Loch Ness monster, the Beast of Bodmin and other associated British photographic pranks.

However, what if these “flying saucer” events are of very short duration? I would assume that very advanced inter-stellar explorers would probably have fast moving space ships. (Why, given these speedy vehicles, they should travel across the vast immensities of space specifically to fiddle with the genitalia of American matrons is beyond me.) By way of comparison, in all my years of watching experimental planes coming in to land at Boscombe Down (an airfield at which experimental planes are taken for test flights) I have never managed to photograph one of them.

So, should the ubiquity of cameras need to be corrected for the sluggishness of camera users, rather like the way Carl Sagan controlled for the Drake equation (used to estimate the number of active, communicative extra-terrestrial civilizations in the Milky Way galaxy) by calculating how many civilizations would have blown themselves up in their “technological adolescence”? (Sagan was pleased to hear what an impact that phrase had on his listeners). I think a correction is necessary.

I could not time it exactly, but I think it usually takes me at least 30 seconds between seeing something I feel I must photograph and getting a photo of it, or of the remains of it. I cannot time this exactly, because my only stopwatch is an application on the same device which has the camera.

As a consequence of fiddling with the iPhone, and trying to keep an eye on my watch as I did so I finally worked out how to use the little camera pictogram, and can now open my camera more quickly. (You may estimate my performance IQ by this admission).

I now stand poised to record extraordinary events of very short duration.

Thank you