Tuesday, 30 September 2014

Can Alzheimer's disease be prevented?


If you are close to Edinburgh, you can attend in person, if not it will have to be the private plane again, but remember the drinks reception is free. Otherwise, this will give you a pointer to a researcher working in the field. Symbol-digit is the quickest and most reliable test of memory problems in the elderly. Who says paper and pencil tests don’t have real life applications?

The first seminar in the Centre for Cognitive Ageing and Cognitive Epidemiology's 2014-15 seminar series will take place next Tuesday, 7th October 2014 at 5pm in F21, Department of Psychology, 7 George Square. Admission is free, booking is not necessary and the seminar will be followed by a drinks reception in the department concourse.

The seminar will be given by Professor Karen Ritchie, senior Research Director with the French National Institute of Medical Research (INSERM) and Honorary Professor with the Department of Epidemiology and Public Health, Imperial College, London.

Title: "Putting your money where your mouth is: can we design programmes to prevent Alzheimer's disease?".

Summary: Once considered an inevitable part of ageing, the dementias are now recognized as pathologies distinct from the normal brain ageing process.
Consequently over the past three decades both clinical and epidemiological studies have aimed to demonstrate risk factors specific to dementia, notably Alzheimer's disease. Of the large number of significant risk and protective factors which have been found, many of these are potentially reversible and statistical modelling suggests that reducing exposure may have an even greater impact on future disease incidence than altering genetic predisposition. Most of these exposures occur in middle-age suggesting the need for a life-time approach, intervention strategies which target younger populations and a reconsideration of Alzheimer's disease clinical criteria.

Friday, 26 September 2014

Should educationalists be streamed?

There has long been a debate as to whether educationalists should be streamed, so that the brighter practitioners should not be held up by the slower pace of their less able colleagues. The contrary view is that educationalists of different levels of ability should be mixed together, so that the clever ones can lead the intellectually impaired to better things. It is not clear where the Institute of Education stands on this important policy matter.

This debate is remarkably similar to the question as to whether children should be streamed in schools. Before all else, do a thought experiment: when you stream children, what result would count as success? Certainly if all streamed children do better than un-streamed children then that would count as a clear win. It would show that “correct pace” teaching was good for all.  However, what if bright children race ahead whenever they do not have to wait for their less bright peers? Should that be counted a success, or a partial success, or a failure? The economic and cultural contribution of the brightest minds appears to be considerably greater than that of average citizens, so it might be best to give them a clear run, and settle accounts later with redistributive taxation. On the other hand, if you value the mean value of achievement for the group as a whole, then brighter children should be held back to encourage the others.

On the issue of streaming, Samantha Parsons & Sue Hallam, both at the Institute of Education have written “The impact of streaming on attainment at age seven: evidence from the Millennium Cohort Study” . Oxford Review of Education 24 September 2014. http://www.tandfonline.com/loi/core20

Their work has been prominently reported, which is a good thing. It is based on a very good sample, which is also a good thing. Most citizens will read the newspaper accounts only, so here is the Guardian headline as a guide:

School streaming helps brightest pupils but nobody else, say researchers: Splitting classes by ability undermines efforts to help disadvantaged children, finds research into English primaries

So much for what the public will read and believe to have been proved. What does the actual study reveal?

The Millennium sample a good size, is representative, and there is an increased representation of minority, poor and immigrant groups. The sample is somewhat better than the population averages.The sample studied in the paper was N=2544 of whom 83% were not streamed. The sample size is fine by social science standards, and much better than the modal values in publications, though negligible compared to the 70,000+ in the Deary et al (2007) education paper.

What is less satisfactory is that the authors do their study on the basis of Key Stage 1, when the children are 7.  These ratings are done by teachers on the basis of “informal tests”. I do not know if these are actual tests with published characteristics, or just an overall impression. They also have an earlier baseline teacher assessment called Foundation Skills Profile. For children at school in England these assessments are made on the basis of the teacher’s accumulating observations and knowledge of the whole child.

Seven years of age is rather early to come to any conclusions about teaching methods. This is the earliest age, from a psychometric point of view, that we can get an indication whether they have reading problems of any significance. It is also a little hard to believe that 7 year olds have achievements in science. These teacher assessments are somewhat weak, and insensitive to actual differences in ability. I have looked at them in relation to court cases, and would not put too much reliance on them. As a rule of thumb, if you want to know how well teachers teach, do not rely on teacher’s assessments of progress. Use national examinations marked by others.

Now we turn to the crux of the paper: the difference between schools that stream and schools that don’t. We need to know if schools that stream are different from those schools which don’t in terms of parental background, child ability, and other teaching methods. In particular, we need to know if the scholastic achievements of children in the un-streamed schools have the same means and standard deviations as the achievements of the streamed schools. Otherwise the differences between the overall score of un-streamed children and the overall scores of the streamed children may differ for reasons that are not directly due to streaming.

For example, schools which find they have a very broad range of child abilities (large standard deviation) might have to do streaming; schools with a narrower range of abilities (low standard deviation) might not bother. We need to check that a fair comparison is being made.

The results in Fig 1 suggest that those who were streamed (17% of this sample) were duller and more variable than the majority who were un-streamed. Looking within the streamed children, the brightest are only a little above the average of the un-streamed majority. Case proved that streaming is not worth it? Not at all.

This is yet another case when very simple statistics would be a great help. Showing the actual distribution of the Stage 1 total scores for the steamed 17% and the un-streamed 83% would be useful. The streamed children are out-numbered four to one. 222 children were in the ‘top’ stream, 130 in the ‘middle’ stream and 94 in the ‘bottom’ stream. These are reasonable numbers, but hardly substantial ones. We must check that the decision to stream children is not influenced by student heterogeneity. As far as I can see, these checks have not been done.

The authors have done regression analyses so as to predict the Key 1 scores. This potentially obscures the position in that it denies us a clear contrast between the streamed/un-streamed groups. Instead, you have to try to derive these differences from the beta coefficients.

The authors note: Standardised regression coefficients do not directly indicate the effect of a unit change in the outcome, they rather represent change in terms of standard deviations. The predictor with the biggest regression coefficient is the most important predictor of the outcome, regardless of the direction of the relationship.

One little-reported conclusion: The child’s earlier academic performance, as measured by the Foundation Stage Profile (FSP) score, was identified as the most significant predictor of later academic attainment as measured by KS1 performance.

Another little-reported conclusion: Among the family socio-economic characteristics, parental education remained significantly associated with the KS1 outcomes, after controlling for all other variables in the model. Household income appeared to be an independent risk factor for overall KS1 performance, as did lone parenthood for KS1 maths attainment.

Comment: This first conclusion is what Heiner Rindermann found in many international samples: parental education is more important than parental wealth. That raises the possibility that unmeasured genetic factors make a contribution.

Although the authors have not provided what I regard as a proper comparison between schools, they surprisingly say:

These differences have developed over a short period of time, since the children began compulsory schooling. The findings support the divergence hypothesis (e.g. Linchevski & Kutscher, 1998) which is of particular concern given that prior teacher rated ability at age five was taken into account, along with a range of child and family and school factors.

I am not persuaded on the basis of this paper that “these differences have developed” as a consequence of schooling. I will of course check to see what further analyses they may have done. There might be no differences in standard deviations between the two groups, so it may be a moot point.

Under “Implications” they write:  The evidence from this and earlier research demonstrates that streaming does not of itself raise attainment for all children (e.g. Barker Lunn, 1970; Ferri, 1971) and widens the gap between low and high attaining pupils. Schools need to take this into account when planning the ability grouping structures that they adopt.

I do not think they can argue that, on the basis of their results. They have already said that the prior measures of the Foundation Stage Profile account for a large part of the variance in children’s attainments. The foundation profile has a large gaping hole in it (see below). They have not fully explored the reasons for the possible differences between the streamed and un-streamed children, such that streaming might be applied where there are wide differences in ability.

What dog did not bark in the night? There are no cognitive ability measures reported. None. Why do so many authors fail to consider that intelligence may be a factor in educational attainment? Why leave this out, when it can be measured quickly, and always accounts for a significant proportion of educational outcomes?

Finally, here is my summary:

Although sample sizes are small and the prior measures of ability are weak, those prior abilities are the best predictors of attainments at age 7, and although we cannot be sure that streamed schools haven’t got a wider range of abilities than un-streamed schools, nonetheless it looks as if streaming does not lift the overall abilities  of students.

Snappy headlines are one of my most evident whole-person special skills.



I. J. Deary, S. Strand, P. Smith and C. Fernandes (2007) Intelligence and educational achievement. Intelligence 35, 1, pp13-21.

Thursday, 25 September 2014

Slaves of defunct philosophies

I had almost forgotten about the London slaves, who were said to have been held captive in a house for 30 years, and then finally discovered in November 2013 when they were supposedly liberated by a charity.



Now it turns out that the authorities have finally come to a decision about the couple who allegedly held the slaves captive in a South London house. The wife has been told she will not be facing any charges, and the man has been remanded on a sexual charge. One presumes he is accused of having committed sex offences against some or all of the three women. The Police say: "A 73-year-old man arrested on Thursday 21 November 2013 in connection with an investigation into slavery and domestic servitude and further arrested in relation to serious sexual offences on Tuesday 29 July 2014 has been re-bailed to a date in mid-December."

As the jargon has it, this seems to be a case of Narrative Collapse. The women were not random citizen captured on the street, but members of a Maoist cult, and they are said to have gone out shopping during their supposed confinement. The Police originally spoke of “psychological handcuffs” to account for them not having escaped over the decades, until they did, indeed, escape by the stratagem of walking out the front door.

Why bother about this case? Credulity is inversely related to intelligence. The description of people being slaves brings to modern minds a black man captured in Africa, chained, transported to America, and beaten and abused on a sugarcane or cotton plantation.  Those journalists, politicians, charity and Police spokespersons who spun the narrative on this case and who ensured it was given wide coverage in the media for many days were keen to use the concept of slavery as a legitimate description of what was in fact an odd household of self-selected ultra-leftists. They took journalists for fools, with some success, and the public for fools, perhaps with a little less success. Nonetheless, they got their headlines, and most citizens are trusting, or gullible, and those crucial headlines helped them convince politicians. The Modern Slavery Bill was presented to Parliament a month or two after the story was splashed in the media, and the Bill is making good progress, and is now at the Committee stage. Job done.



Postscript: If you and some of your old lovers are still hanging on in a neglected house, waiting for the revolution, or indeed the counter-revolution, and have a room with an old photo of Hitler, Stalin, Mao or, at a pinch, Che Guevara, pasted to the wall, perhaps you would like to give the freedom charity a call. Show some courage, tell your story, and hope it gets made into a film.

Remember John Maynard Keynes’ remark: 

“The ideas of economists and political philosophers, both when they are right and when they are wrong are more powerful than is commonly understood. Indeed, the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually slaves of some defunct economist.”

Monday, 22 September 2014

Don’t sweat the big stuff


In the last few days I have been a little quieter than usual. Naturally, the Scottish referendum took up some of my time, an important matter which should attract the attention of the chattering and commenting classes. Meditating on such high matters took up my time, even though I wrote nothing about it. I also spent a little time commenting on a string of beheadings in the Middle East, which led to a radio interview which posed the predictable question “Why do they do it?” and my predictable answer “To terrify their opponents”. On Sunday I was further distracted by the notion, promulgated by The Sunday Times that the Cheltenham codebreakers are recruiting dyslexics (and dyspraxics, and the differently neurally abled) to give their own, very special perspective on what the enemy is doing, which could not be afforded by those able to read and write. Here is a little detail on this great matter:

A 35-year-old IT specialist by the name of Matt is the chairman of the dyslexic and dyspraxic support community at the listening post. He told the Sunday Times: “What people don’t realise is that people with neuro diversity usually have a ‘spiky-skills’ profile, which means that certain skill areas will be below par and others may be well above.

“My reading might be slower than some individuals and maybe my spelling is appalling, and my handwriting definitely is… but, if you look at the positive side, my 3D special-perception awareness and creativity is in the 1 per cent of my peer group.” 

Read more: http://www.gloucestershireecho.co.uk/Code-breakers-GCHQ-dyslexic-just-like-Alan-Turing/story-22958534-detail/story.html#ixzz3E3eZkTeM

Baldly, the article claimed that Alan Turing was dyslexic. I think this is very silly. Can anyone direct me to the evidence? I have read what his Sherborne teacher said about him (“one of the two brightest boys I have ever taught”) and read some of his papers, in awe, and I see no such deficiency. By dyslexia I mean a specific reading backwardness once one has allowed for intelligence (so, in Turing’s case even a slight reading deficiency would potentially count as a disorder). 

However, none of these matters of great import (or great distraction) have been taking up my time. Instead I have been dealing with a very local matter, in which I am one of the representatives of the locals against a wave of property-developing deep basement diggers, who are making lives a misery in central London. This is a very parochial matter. In one way or another it has taken up bits of my time for four years, and now that the planning inspection is underway, I have spent four days, of eight hours each, listening to the local Council’s timid plan for restricting such major works (one storey basements allowed, multiple storey basements prohibited) being torn apart by the (paid) advocates of the basement constructors. Very local, very technical and of interest to intelligence researchers only because the actual battle is being fought on narrow points of planning law, while the protestors are naturally wanting to complain on broad grounds of principle and human emotion. It involves having to explain to my bruised confederates that the Council has gone as far as it dares (central government is in favour of all forms of house building, whatever the impact) and that we have to rally round the lesser evil to get a modicum of relief. (A mild consolation is that the other side are said to have spent £500,000 in order to try to get their way).

As you know, I often look for real life correlates of intelligence. I had always assumed that anyone of any intelligence would turn to Great Matters. For example, changing the (unwritten) British Constitution after the Scottish referendum is a very taxing and great matter. It requires brains as well as considerable historical knowledge. Sorting out the Middle East: who to bomb/kill/arm/pay ransom to, is another intellectual challenge. Explaining to the general public that if dyslexia is given an all-inclusive, low re-definition then it ceases to have nosological significance is another worthy great intellectual task (I might try that one later).  So, why spend any time on something small?

Local matters seem a distraction at such troubled times. Horrible as it may be to watch your walls crack because there is a bulldozer next door digging a basement, there is no intent to kill the neighbours, just to ignore them.

However, it may be intelligent to balance “global importance” against “probability of success”. The small stuff is worth sweating because you might be successful in achieving your aims. Put it at 1 in 150, but it is tangible nonetheless. 150 is said to be the fundamental modal size of human settlements and networks (more and it is hard to recognise everyone, and remember exactly how they have treated you), so that gives a rule of thumb. However, given that at most 4% of the populace are politically active in the most generous sense of that term, even in a small village you are probably having to convince only about 5 people, in order to swing that local group.

On larger matters, even with small populations the size of Scotland, 5 million is a big number to influence, and even the 200,000 activists a challenging number to convince. Sweating the big stuff may be a waste of effort. You will get excited, no doubt, and have a sense of importance, but a very low probability of impact. Somehow, the supposedly great matters assume a moral high ground: they pretend to rise above mere personal concerns. A beheading in a distant land must be of more consequence than a car crash in your own suburban street which has the same effect on a grieving family. Keeping up with the international news is seen as a duty, the local news an indulgent distraction.

Indeed, this may lead to a rule of thumb: activism about all social matters should be conditioned by a probability calculus, a cost benefit analysis of the issue itself, divided by probability of success.

Try sweating the small stuff.

Thursday, 18 September 2014

Fingers, feminism, and bossiness


In the early history of science fiction, and indeed fiction as a whole since Mary Shelley’s Frankenstein, there has been a fascination with humans who have been taken over by sinister forces. In one very early TV science fiction program the small American town was taken over by aliens (yet again: why don’t aliens take over towns in other countries?) who did their dastardly alien tricks on upstanding citizens, operating on them and then releasing them to carry out alien orders.

How to distinguish these interstellar traitors from fine, upstanding, 100% Americans? Even as a child I could see the answer: there were clear drill marks on the back of the necks of the zombies, where something had been implanted: Communism, most probably. However, in this drama, possibly because the drill marks were generally obscured by clothing, another test was applied by the besieged townfolk: the aliens implanted into the bodies of Americans were unable to properly flex their little fingers. Ask them to flex their pinky finger, and democracy is saved.

I have not been particularly interested in fingers. I concede that they are useful, and that to be without them would be a human tragedy, but even in my gratitude I have not accorded them high status.

Now young Woodley strides onto the scene, to remind me that much of great import may be derived from the study of finger length ratios.  Looking at your hands, palm downwards, you will note that when you compare your index finger (number 2, where your thumb is number 1) with your ring finger (number 4) you will find that….. that finger 4 is visibly longer than finger 2. Or perhaps not. The ratio of finger lengths may be a sensitive measure of pre-natal androgen, or a random variation which should not concern us very much, unless we are intrinsically interested in fingers.

Madison, Aasa, Wallert, and Woodley (2014) Feminist activist women are masculinized in terms of digit-ratio and social dominance: a possible explanation for the feminist paradox.


We measured the 2D:4D digit ratios (collected from both hands) and a personality trait known as dominance (measured with the Directiveness scale) in a sample of women attending a feminist conference. The sample exhibited significantly more masculine 2D:4D and higher dominance ratings than comparison samples representative of women in general, and these variables were furthermore positively correlated for both hands. The feminist paradox might thus to some extent be explained by biological differences between women in general and the activist women who formulate the feminist agenda.

They got 25 women at a feminist conference to have both hands scanned (so that finger length ratios could be calculated) and then 24 of them filled in a “Directiveness” questionnaire, which seems to measure dominance and a tendency towards bossiness.

In summary, the feminist activist sample had a significantly smaller (i.e., masculinized) 2D:4D ratio than the general female samples. The size of this difference corresponds approximately to a 30% difference in prenatal testosterone/estradiol ratio, which was the index found to have the strongest association with 2D:4D (Lutchmaya et al., 2004). Directiveness self-ratings also exhibit a large and highly significant difference in the predicted direction. It is notable that the feminist activist sample 2D:4D was also more masculinized than those of the male comparison samples, except for the left hand in the aggregate sample (see Table 2).

This is a small sample, though a big number of feminist activists, given their rarity in the population, and the association with dominance is intriguing.

So what, and what does this have to do with intelligence? Nothing directly. However, there have been claims that the 2d:4d ratio is weakly correlated with intelligence (in another small sample of people).

Marc F. Luxen and Bram P. Buunk.  Second-to-fourth digit ratio related to Verbal and Numerical Intelligence and the Big Five. Personality and Individual Differences 39 (2005) 959–966


There may be something in this finger business. It would be worth checking on a much larger representative sample which has already been tested for intelligence or scholastic ability, and ideally on which genomic data is available.

Wednesday, 17 September 2014

Processing speed: the even quicker version, going fast



On 6 May I posted up my notes on a talk given in Edinburgh by Ian Deary on processing speed, and now here is the written up version of that talk by Ian Deary and Stuart Ritchie which gives much better descriptions of the concepts and the findings.


If you click on the third item “10 quick questions about processing speed” you can download the pdf. I should warn you it contains photos of the participants at the conference, but those can be avoided by readers of a nervous disposition.

As you read the paper, reflect on the fact that it may be the last time you read something from Edinburgh while it is still part of the United Kingdom. Thus, it will have historical as well as intellectual significance.

Monday, 15 September 2014

Gene hunters and gene saboteurs


There is quiet satisfaction in some quarters that the search for the “intelligence genes” is not making much progress. I, on the contrary, am watching the publication of papers with excitement. We know that intelligence is heritable, because consanguinity is related to a similarity in intellect. We don’t know the names of the genes that bring about this effect, nor how they interact to do it. Given that there may be many hundreds of genes building the brain, each contributing a very small effect, finding them may be hard. For once, researchers are getting together the very large samples required, which may need 1,000,000 genomes. We are reaching towards the biological/social science version of CERN.

But, rather like all other activities, for every enthusiast there is an equal and opposite activist, rather like fox hunters and hunt saboteurs. This may need a little explanation for those readers who have the misfortune not to live in England. Fox hunting is a 16th Century country pursuit, commemorated in paintings of red coated, top hatted gentlemen on fine mounts jumping over hedges in pursuit of the red fox. Its association with the gentry makes it a status marker, implying that fox hunters are Conservatives, Protestants, fond of flagellation and possibly of wearing double breasted pyjamas in bed. Until I started living part of my life in the English countryside, I did not know that for every rider there is at least one countryman hunt follower in a small van. They are farm workers, electricians, plumbers, builders and shopkeepers. I join them by chance on country roads sometimes, and stand with them briefly as with their binoculars they watch the hunt work across the landscape and explain to me, in detail, what is going on. Tradition maintained.

On the other side are a largely urban species, the hunt saboteurs, associated with rabid socialism, multiply-occupied scruffy bed-sitters, vegetarianism and sleeping naked several to a bed. Some have the secret vice of having rich parents. They disrupt hunt meetings, lay false scents, and get into rows, which occasionally lead to minor violence. England being England, it has also led to romantic liaisons with the fox hunting toffs, and at least one marriage. Bless.

(For those still confused, watch Downton Abbey, and remove the small delivery vans).

Back to genetics. The gene saboteurs are defending the citadel of environmentalism, and probably regard each large scale genetic study of intelligence as a waste of resources. The gene hunters are, according to different views, either upholding the highest traditions of the Enlightenment, or dragging us into social Darwinism, nature red in tooth and claw. All these conflicting views contend in scholarly publications. Who really doubts that this is a great time to be alive?

The gene hunting enthusiasts are making progress, in my view. They are raising their standards, roping in even more researchers across the world, and using statistical approaches which are likely to minimise false positives. The gene saboteurs may be laying false scents, arguing that slow progress in phase 2 (gene identifying) means that doubt can be cast on phase 1 results (heritability estimates), but against their will they are driving up the standard of proof, though I very much doubt they want research on the genetics of intelligence funded, and certainly don’t want the databases opened up for racial comparisons, an obvious additional pathway to cracking the code.

Nature (the magazine) described the state of play as: Smart genes prove elusive: Study of more than 100,000 people finds three genetic variants for IQ — but their effects are maddeningly small.


The article says that 106,000 genomes have yielded 69 genes of interest for their links with scholastic achievement, of which 3 may be linked to intelligence. Every article should have a critical comment, in addition to the author of the study saying something, and in the sceptical box Nature says: “With effects this small, the chances that they represent false positives are vastly increased,” says Kevin Mitchell, a neurogeneticist at Trinity College Dublin who says he was decidedly underwhelmed by the study. “While intelligence — and proxy measures such as cognitive test performance or educational attainment — are quite heritable, the idea that this trait is determined by common variants in the population at large is really unproven,” he says.

Interesting that the response is “underwhelmed”. Very few psychological studies muster 106,000 subjects, and if you ensure that your statistics are rigorous then a small effect size need not indicate that the findings are false positives: they may be entirely true but weak positives.

To my mind the history of progress in science tends to oscillate between practice and theory. In my cynical moods I think that theory takes the back seat much of the time, because observation and plain data crunching can take you a long way. At the very least, you can work out the shape of the terrain, and often find flakes of gold. However, there comes a time when just working through the gravel pit looking at individual chips of stone has to give way to an engaging, broad impact but testable hypothesis. Someone is going to have to come up with a better theory as to how the genome builds the proteins that build the organism. The code breakers at Bletchley Park used cribs much of the time: they knew that enemy weather stations would have to report the weather, submarines the positions of shipping, and the very most important orders might include the sequence of letters “Hitler”. (I have encoded this sequence on an Enigma machine myself, wearing white gloves, not out of deference to afore-named assassin, but as a courtesy to the curator of the Bletchley Park museum, to protect the machine I was using). There must be genetic cribs of some sort, so that instead of looking at the limited 4 letter alphabet of the genetic code researchers begin to recognise the odd word, or even short sentence.

If a million genomes are required, then that should be the next step, and those who are “underwhelmed” with the current state of play should urge on the funding of a global program so that we be overwhelmed when we break the code of what makes us a thinking, knowing species.

Friday, 12 September 2014

Fat prejudice and slim conclusions


With the Woodley challenge on correlation still reigning supreme, what are we to make of a correlation between perceived prejudice against fat people (as reported by fat people), and their subsequent weight gain?

Of the 2,944 eligible participants in the study, 5% reported weight discrimination. This ranged from less than 1% of those in the ‘normal weight’ category to 36% of those classified as ‘morbidly obese’. There are somewhat more women in the fat category. Men and women reported similar levels of weight discrimination.  Those who reported prejudice were already fat, as weighed 2 years before; then gave their estimates as to whether they had been subjected to negative treatment (without actually having to say that it was on account of their being fat); and were then weighed 2 years later; by which time four years had passed and they had gained 0.95 Kg in weight, whereas the majority, who had not reported unfriendly treatment, had lost 0.71 Kg in weight.

They were all drawn from the English Longitudinal Study of Ageing, so we have a large and representative sample of over 50 year olds, and need not worry on that score.

Sarah E. Jackson, Rebecca J. Beeken and Jane Wardle. Perceived Weight Discrimination and Changes in Weight, Waist Circumference, and Weight Status 

Objective: To examine associations between perceived weight discrimination and changes in weight, waist circumference, and weight status.
Methods: Data were from 2944 men and women aged 50 years participating in the English Longitudinal Study of Ageing. Experiences of weight discrimination were reported in 2010-2011 and weight and waist circumference were objectively measured in 2008-2009 and 2012-2013. ANCOVAs were used to test associations between perceived weight discrimination and changes in weight and waist circumference.
Logistic regression was used to test associations with changes in weight status. All analyses adjusted for baseline BMI, age, sex, and wealth.
Results: Perceived weight discrimination was associated with relative increases in weight (11.66 kg, P<0.001) and waist circumference (11.12 cm, P50.046). There was also a significant association with odds of becoming obese over the follow-up period (OR56.67, 95% CI 1.85-24.04) but odds of remaining obese did not differ according to experiences of weight discrimination (OR51.09, 95% CI 0.46-2.59).
Conclusions: Our results indicate that rather than encouraging people to lose weight, weight discrimination promotes weight gain and the onset of obesity. Implementing effective interventions to combat weight stigma and discrimination at the population level could reduce the burden of obesity.


So, let us look at this work from the Woodley perspective of correlation and causation. We have fat persons and normal weight persons. These probably differ in many ways, which probably include intelligence and personality, social class and wealth, and genetics. We could study these differences, including looking at how many people in each category report prejudice.

I have already discussed some of these matters in “Fat is an intellectual issue” and “Diet is an IQ test”



However, the authors do not compare fat and normal weight people. They compare those that report prejudice versus those who do not. They find that the prejudice reporters are fatter and poorer than the large majority who do not report prejudice. Then, they conclude:  Our results indicate that rather than encouraging people to lose weight, weight discrimination promotes weight gain and the onset of obesity.

How do they conclude that?

Senior author Professor Jane Wardle, director of the Cancer Research UK Health Behaviour Centre at UCL, is reported as saying: “Our study clearly shows that weight discrimination is part of the obesity problem and not the solution. Weight bias has been documented not only among the general public but also among health professionals; and many obese patients report being treated disrespectfully by doctors because of their weight. Everyone, including doctors, should stop blaming and shaming people for their weight and offer support, and where appropriate, treatment.”

It is a bit of a jump from a person feeling discriminated against, to concluding that they have actually been named and shamed.

Dr Sarah Jackson said: “Most people who are overweight are aware of it already and don’t need it pointed out to them. Telling them they are fat isn’t going to help - it is just going to make them feel worse.

“There are lots of different causes of obesity, yet a lot of blame just seems to be on individuals and a lack of will power. Raising awareness of some of the factors involved might make it easier not to blame people.”

In deference, I should say that although all three authors are credited with this argument, one or more of them know it to be in error, because in the paper itself they say: We cannot be sure whether discrimination preceded weight gain or vice versa. It is therefore not possible to establish causal relationships; i.e. whether people gain weight as a consequence of experiencing weight discrimination, or whether gaining weight makes people more likely to experience weight discrimination or attribute experiences of discrimination to their weight.

The Press Office at UCL correctly say: “Because this was a population survey and not an experimental study, it cannot conclusively confirm that the positive association observed between discrimination and weight gain is causal”. However, they still give it the headline ‘Fat shaming’ doesn’t encourage weight loss and the Press have picked that line as their lead in widespread reporting.

Notice the obvious: a person’s perception that they are being treated unfairly (probably because of being over-weight) is not an objective measure like their weight. They may be being over-sensitive. Their perceptions about unkind treatment may be part of a set of distorted judgments about food, body image and self worth. The measures taken do not allow us to come to any judgment about this. Neither are there any intelligence or personality measures, which would have been instructive, even if they showed no difference, because we could have discarded them as possible causes of the difference.

Remember, the perception that “people treat me badly (probably because I am fat)” is held by only 0.7% of normal weight people (interesting it should be that high) but as many as 36% of the very fat people. I assume that a Chi square would reveal a strong association between heavy weight and perceived prejudice.

Let us compare the 150 people who report prejudice against them with the 2794 people who do not. The differences are shown in terms of p values, but this reliance on statistical significant might obscure the sizes of the differences. They do not differ in height. They differ massively in weight: 97 Kilos versus 75 Kilos. Just pause a moment on those figures. That is an effect size of 1.44. Wow. The no-discrimination group are hardly slender, with a BMI of 27.17 where 25 is the official preferred figure (and in fact 22 is the most conducive to normal health). The discriminated against have an average BMI of 35.46 They are also quite a bit poorer. Do they differ in intelligence or personality? Likely, but no measures of these variables are given.

Incidentally, the authors assume that not liking fat people is a fallacious pre-judgement. The also assume that “fat-shaming” is actually widespread as an activity. Fat avoiding is part of freedom. So is thin avoiding. So is avoiding psychologists. Preferences must not always be crimes.

I think that the authors have shown caution in the paper, but far less caution in their public statements as to what is in the paper. Perhaps their cautions were ignored, but the UCL Press Office is punctilious in letting authors vet their own statements for use by the Press. Of course, being unkind to over-weight people is uncivil and bad manners. One should not even be uncivil to psychologists. However, I think that it would have been better to report the correct conclusion:

People who think that others are prejudiced against them because they are fat don’t lose weight.

Thursday, 11 September 2014

Steven Pinker on university standards: Harvard


It would be great if Prof Pinker had decided to reach out to Psychological Comments in order to join our occasional series on university standards, but he has done the next best thing: he has written a heartfelt account of teaching at Harvard, which serves our purpose very well. My thanks to an alert reader for this:


In brief, Pinker is arguing against those who would have university entry be based largely on holistic criteria: general enthusiasm, good works, helping the unfortunate (excluding unfortunate academics), playing sports, and being diverse in some required manner. The latter loophole allows you to encourage or prevent racial and religious groups, and to make special provision for those whose parents have donated large sums.

Pinker makes an admission I find quite shocking: A few weeks into every semester, I face a lecture hall that is half-empty, despite the fact that I am repeatedly voted a Harvard Yearbook Favorite Professor, that the lectures are not video-recorded, and that they are the only source of certain material that will be on the exam. I don’t take it personally; it’s common knowledge that Harvard students stay away from lectures in droves, burning a fifty-dollar bill from their parents’ wallets every time they do.

Well, I thought I was the only one. I was highly ranked as a teacher in my medical school, but I assumed that the more-than-slightly-better-known Prof Pinker would command a full lecture hall. Other psychology teachers happily go to talks by Steven Pinker, and read his many books. Why not these brats?

Pinker argues that they are not at lectures because they are following the holistic pursuits that gained them entry: music, drama, sports, dance, comedy. What is to be done with these all-too-well-rounded but thoroughly anti-intellectual, uncultivated , and wilfully untutored minds?

Pinker muses:

If only we had some way to divine the suitability of a student for an elite education, without ethnic bias, undeserved advantages to the wealthy, or pointless gaming of the system. If only we had some way to match jobs with candidates that was not distorted by the halo of prestige. A sample of behavior that could be gathered quickly and cheaply, assessed objectively, and double-checked for its ability to predict the qualities we value….

We do have this magic measuring stick, of course: it’s called standardized testing. []test-based selection used to be the enlightened policy among liberals and progressives, since it can level a hereditary caste system by favoring the poor and smart over the rich and stupid.

So why aren’t creative alternatives like this even on the table? A major reason is that popular writers like Stephen Jay Gould and Malcolm Gladwell, pushing a leftist or heart-above-head egalitarianism, have poisoned their readers against aptitude testing. They have insisted that the tests don’t predict anything, or that they do but only up to a limited point on the scale, or that they do but only because affluent parents can goose their children’s scores by buying them test-prep courses.

Pinker goes on to show that these claims are wrong: ability and scholastic tests are our best predictors overall, and are little influenced by tuition. Standardized testing would be fairer than Harvard’s messy current system. Students selected on that basis might even have intellectual interests.

How strange that we even have to argue that entry to an academic establishment should be on academic aptitude, when that should be obvious. Stranger too that the inept entry system confers advantages to graduates because employers assume that if they went to Harvard they must have done so on merit, and be bright and well educated.

Finally, if you wondered why people read Steven Pinker, look at these two paragraphs, given early in his essay in reply to the suggestion that, instead of the usual objectives, education should be focussed on the holistic goal of building a self, a unique being, a soul. Pinker reports he doesn’t know how to do that, but suggests:

It seems to me that educated people should know something about the 13-billion-year prehistory of our species and the basic laws governing the physical and living world, including our bodies and brains. They should grasp the timeline of human history from the dawn of agriculture to the present. They should be exposed to the diversity of human cultures, and the major systems of belief and value with which they have made sense of their lives. They should know about the formative events in human history, including the blunders we can hope not to repeat. They should understand the principles behind democratic governance and the rule of law. They should know how to appreciate works of fiction and art as sources of aesthetic pleasure and as impetuses to reflect on the human condition.

On top of this knowledge, a liberal education should make certain habits of rationality second nature. Educated people should be able to express complex ideas in clear writing and speech. They should appreciate that objective knowledge is a precious commodity, and know how to distinguish vetted fact from superstition, rumor, and unexamined conventional wisdom. They should know how to reason logically and statistically, avoiding the fallacies and biases to which the untutored human mind is vulnerable. They should think causally rather than magically, and know what it takes to distinguish causation from correlation and coincidence. They should be acutely aware of human fallibility, most notably their own, and appreciate that people who disagree with them are not stupid or evil. Accordingly, they should appreciate the value of trying to change minds by persuasion rather than intimidation or demagoguery.

A virtuous prospectus, uncluttered by priests, and within the bounds of the possible. As Burke observed in A Vindication of Natural Society, all happiness is connected with the practice of virtue, which necessarily depends upon the knowledge of truth.

Wednesday, 10 September 2014

Altruistic Ebola Yo-Yo’s




The British nurse who caught Ebola and had to be flown back to a hospital in London to get treated plans to return to Sierra Leone:

“It's the least I could do to go back and return the favour to some other people, even just for a little while,” Mr Pooley told the Guardian.

“The more help they get the less chance there is they get sick. If they get sick they are just going to end up in a ward in Kenema with less chance than I had."

Usually, I am in favour of people being helpful. It certainly beats breaking into an Ebola treatment centre and stealing the mattresses. However, I feel uncomfortable about Western health workers going to Africa, catching a disease they catch only if they don’t take the necessary precautions, and then being flown out for treatment which is not available to their work colleagues in Africa. They have a “get out of jail” card that other nurses do not, and many have died as a consequence.

Furthermore, if Mr Pooley gets some other disease in Sierra Leone, will he be flown back to London again, and then fling himself back into his own version of helping in Africa? He seems to have a predilection for solo working outside well organised treatment facilities. There seems to be a very strong case for examining his skills at barrier nursing before letting him go anywhere. There is no specific treatment for the average African patient (as opposed to Western health visitor) other than standard nursing, plus precautions for staff. Bluntly, what can he do that an appropriately trained and managed West African nurse cannot do? His treatment costs and plane fares would probably hire lots of local workers, and would also pay for lots of rubber gloves which West African nurses lack, plus unpaid wages.

His nursing task is not a highly technical one, like sequencing the Ebola virus and checking the mutation rate. He will not be designing new drugs of the sort he took himself. He will not be guiding a computer-driven laser into an afflicted patient. All he will be doing is administering standard nursing care and, with any luck, avoiding getting and spreading the disease.

I am perfectly willing to accept European exceptionalism as a general principle derived from five centuries of notable achievement, but in this instance I think Mr Pooley should listen to his mother: she was very relieved when, as part of infection control, his passport was incinerated.