IQ as a symptom of general biological fitness again

People with poor thinking skills may be at higher risk of heart attack or stroke, a study has shown. Scientists made the discovery after monitoring the progress of almost 4,000 individuals with an average age of 75 for three years.

At the start of the study, participants had their high-level thinking skills evaluated by tests and were graded accordingly.

Those in the lowest test score group were 85% more likely to have a heart attack and 51% more likely to have a stroke than members of the highest group.

Lead researcher Dr Behnam Sabayan, from Leiden University Medical Centre in the Netherlands, said: 'These results show that heart and brain function are more closely related than appearances would suggest.  'While these results might not have immediate clinical translation, they emphasise that assessment of cognitive function should be part of the evaluation of future cardiovascular risk.'

Dr Sabayan added: 'Performance on tests of thinking and memory are a measure of brain health. Lower scores on thinking tests indicate worse brain functioning.

'Worse brain functioning in particular in executive function could reflect disease of the brain vascular supply, which in turn would predict, as it did, a higher likelihood of stroke.

'And, since blood vessel disease in the brain is closely related to blood vessel disease in the heart, that's why low test scores also predicted a greater risk of heart attacks.

SOURCE

A syndrome of general biological fitness appears again

I have been pointing out for many years that there seems to be a syndrome of general biological fitness -- such that high IQ people are healthier, live longer and have better emotional balance. High IQ, in other words, is just one part of general bodily good functioning. The recent study below is another indicator of such an association and goes on to show that the link is genetic.  Some people are just born healthier and fitter. If so, all your bits work well -- including your brain, which is just another bodily organ.   A wise man from long ago knew that.  He said: "For he that hath, to him shall be given: and he that hath not, from him shall be taken even that which he hath." (Mark 4: 25).  "All men are equal" exists neither in the Bible nor in life

The association between intelligence and lifespan is mostly genetic

By Rosalind Arden et al.

Abstract

Background: Several studies in the new field of cognitive epidemiology have shown that higher intelligence predicts longer lifespan. This positive correlation might arise from socioeconomic status influencing both intelligence and health; intelligence leading to better health behaviours; and/or some shared genetic factors influencing both intelligence and health. Distinguishing among these hypotheses is crucial for medicine and public health, but can only be accomplished by studying a genetically informative sample.

Methods: We analysed data from three genetically informative samples containing information on intelligence and mortality: Sample 1, 377 pairs of male veterans from the NAS-NRC US World War II Twin Registry; Sample 2, 246 pairs of twins from the Swedish Twin Registry; and Sample 3, 784 pairs of twins from the Danish Twin Registry. The age at which intelligence was measured differed between the samples. We used three methods of genetic analysis to examine the relationship between intelligence and lifespan: we calculated the proportion of the more intelligent twins who outlived their co-twin; we regressed within-twin-pair lifespan differences on within-twin-pair intelligence differences; and we used the resulting regression coefficients to model the additive genetic covariance. We conducted a meta-analysis of the regression coefficients across the three samples.

Results: The combined (and all three individual samples) showed a small positive phenotypic correlation between intelligence and lifespan. In the combined sample observed r = .12 (95% confidence interval .06 to .18). The additive genetic covariance model supported a genetic relationship between intelligence and lifespan. In the combined sample the genetic contribution to the covariance was 95%; in the US study, 84%; in the Swedish study, 86%, and in the Danish study, 85%.

Conclusions: The finding of common genetic effects between lifespan and intelligence has important implications for public health, and for those interested in the genetics of intelligence, lifespan or inequalities in health outcomes including lifespan.

SOURCE

Your poverty is in your brain

We sort of knew that already.  The correlation between low IQ and poverty is well-attested. The latest journal article below however takes the story a bit further in that it identifies which brain regions are responsible.  Certain areas of poor people's brains are actually shrunken! The authors seem to have frightened themselves by their boldness, however, as they have tacked a totally illogical conclusion on to their findings.

If poverty is a result of the shrunken brain you were born with, does it not follow that there is not much you can do about it?  The authors below avoid that conclusion.  Instead they say that poor households "should be targeted for additional resources aimed at remediating early childhood environments".   An hereditary problem can be fixed by changing the environment?  That's a pretty good Non Sequitur as far as I can see.

It's not totally daft in that genetics accounts for only about two thirds of IQ.  There are some other influences that have an effect.  But all the research shows that family environment is NOT part of those other influences on IQ.   It's jarring but that is what all the twin studies show. So the hairy lady and her colleagues below are just ignoring the evidence.  But they need to in order to sound nicely Leftist about it all.

Footnote:  The authors of course avoid the term "IQ" like the plague but the standardized tests  of  academic achievement they used are little more than IQ tests and correlate highly with acknowledged measures of IQ.  So their findings show that IQ, income and brain development all cluster together.


Association of Child Poverty, Brain Development, and Academic Achievement

By Nicole L. Hair et al.

ABSTRACT

Importance:  Children living in poverty generally perform poorly in school, with markedly lower standardized test scores and lower educational attainment. The longer children live in poverty, the greater their academic deficits. These patterns persist to adulthood, contributing to lifetime-reduced occupational attainment.

Objective:  To determine whether atypical patterns of structural brain development mediate the relationship between household poverty and impaired academic performance.

Design, Setting, and Participants:  Longitudinal cohort study analyzing 823 magnetic resonance imaging scans of 389 typically developing children and adolescents aged 4 to 22 years from the National Institutes of Health Magnetic Resonance Imaging Study of Normal Brain Development with complete sociodemographic and neuroimaging data. Data collection began in November 2001 and ended in August 2007. Participants were screened for a variety of factors suspected to adversely affect brain development, recruited at 6 data collection sites across the United States, assessed at baseline, and followed up at 24-month intervals for a total of 3 periods. Each study center used community-based sampling to reflect regional and overall US demographics of income, race, and ethnicity based on the US Department of Housing and Urban Development definitions of area income. One-quarter of sample households reported the total family income below 200% of the federal poverty level. Repeated observations were available for 301 participants.

Exposure  Household poverty measured by family income and adjusted for family size as a percentage of the federal poverty level.

Main Outcomes and Measures:  Children's scores on cognitive and academic achievement assessments and brain tissue, including gray matter of the total brain, frontal lobe, temporal lobe, and hippocampus.

Results:  Poverty is tied to structural differences in several areas of the brain associated with school readiness skills, with the largest influence observed among children from the poorest households. Regional gray matter volumes of children below 1.5 times the federal poverty level were 3 to 4 percentage points below the developmental norm (P less than .05). A larger gap of 8 to 10 percentage points was observed for children below the federal poverty level (P less than .05). These developmental differences had consequences for children's academic achievement. On average, children from low-income households scored 4 to 7 points lower on standardized tests (P less than .05). As much as 20% of the gap in test scores could be explained by maturational lags in the frontal and temporal lobes.

Conclusions and Relevance:  The influence of poverty on children's learning and achievement is mediated by structural brain development. To avoid long-term costs of impaired academic functioning, households below 150% of the federal poverty level should be targeted for additional resources aimed at remediating early childhood environments.

JAMA Pediatr. Published online July 20, 2015. doi:10.1001/jamapediatrics.2015.1475

IQ rediscovered in Britain

Across Britain, teenagers are awaiting nervously for their GCSE results to arrive next month.  But however they fare, they can put some of their grades down to their parents, scientists suggest.

In what is likely to further fuel the endless nature versus nurture debate, researchers found between 54-65 per cent of GCSE results are down to nature – the genes we inherit.

Genes were more important than the role played by the home and school combined. Home was responsible for 14 per cent of GCSE results and school quality 21 per cent.

The new research showed the same genes affect performance across a much wider spectrum of subjects than just English, Maths and Science, which earlier research found to be about 60 per cent down genetically decided.

Genetic factors also affected results in history and geography, second languages, business studies, computing, art and drama, the researchers found.

Scientists from King's College London analysed genetic data from 12,500 identical and non-identical twins to assess the importance of genetic factors in academic achievement.
GCSE SUCCESS IS IN YOUR GENES

The new research showed the same genes affect performance across a much wider spectrum of subjects than just English, Maths and Science, which earlier research found to be about 60 per cent down genetically decided.

Genetic factors also affected results in history and geography, second languages, business studies, computing, art and drama, the researchers found.

Scientists from King's College London analysed genetic data from 12,500 identical and non-identical twins to assess the importance of genetic factors in academic achievement.

Surprisingly, when the data was analysed and intelligence was stripped out of the results, genetics still played a major role in GCSE performance – accounting for a lower percentage, but still between 45 per cent and 58 per cent of exam results.

Each twin pair grew up in the same home and attended the same schools, so the researchers could take environmental impact to be constant.

They then compared the GCSE results of the identical twins - who share 100 per cent of their genes - with those of the non-identical twins - who share only 50 per cent of their genes.

By comparing the two sets and subtracting the impact of environment, the scientists disentangled the comparative weight of nature and nurture on the GCSE scores.

The twins were also tested for intelligence to see what role it played in GCSE results. Intelligence is highly heritable – if our parents are bright sparks, we are likely to be as well.

Surprisingly, when the data was analysed and intelligence was stripped out of the results, genetics still played a major role in GCSE performance – accounting for a lower percentage, but still between 45 per cent and 58 per cent of exam results.

The researchers suggest this is because other factors – which also have a high genetic component – such as personality and motivation may be playing a role in exam scores.

Dr Rimfeld said: 'Our findings suggest that many of the same genes influence achievement across a broad range of disciplines, moving beyond core subjects such as English and maths to include humanities, business, art and languages.

'For the first time, we found that these general genetic effects on academic achievement remained even when the effects of general intelligence were removed.'
Scientists from King's College London analysed genetic data from 12,500 identical and non-identical twins to assess the importance of genetic factors in academic achievement (file image)

Scientists from King's College London analysed genetic data from 12,500 identical and non-identical twins to assess the importance of genetic factors in academic achievement (file image)

She added: 'What does it all mean? These results don't have specific implications for teachers in the classroom right now but they do add to the knowledge of why children do differ so widely in their educational achievement.'

The researchers say in the future, educational techniques could take into account genetic factors.

Robert Plomin, another of the study's authors said understanding which genetic factors influence education could lead to 'educationalists develop effective personalised learning programmes, to help every child reach their potential by the end of compulsory education.'

Teachers, however, greeted the study with caution.

Christine Blower, General Secretary of the National Union of Teachers, said: 'Teachers remain committed to the idea that all students are capable of success, and that low expectations – easily derived from research like this – are a major obstacle to such success.'

Prof John Hardy, Professor of Neuroscience, UCL, said: 'Twin studies are a mainstay of behavioural genetics, but they make a simple assumption that is unlikely to be true: that is that we treat identical twins the same as we treat non-identical twins (who look much more different from each other).

'These results are interesting, therefore, but by no means definitive and it would be unwise to make educational decisions based on these data.'

Professor Timothy Spector, Professor of Genetic Epidemiology, King's College London, said: 'Studies showing exam achievements (like IQ) have a strong genetic influence are not new. Unfortunately they are usually over-interpreted as presenting falsely a notion of fixed destiny.'

SOURCE

The wide-ranging influence of genetics

The Left long denied the influence of genetics but now simply ignore it.  The study below is therefore powerful evidence of just how wrong they are.  Hans Eysenck, a considerable student of genetics, once said to me, "It's ALL genetic".  He was of course making a conversational statement to a colleague rather than a precise scientific one but the present study does confirm one sense of what he said:  ALL traits have a substantial genetic component. And the writer below makes the correct and important point that the 50/50 split observed is only an average and that the genetic contribution varies from trait to trait.  So the findings do not overturn the usual finding that IQ is about two thirds genetic

It's a question that dogged scientists for close to a century and Queensland researchers say they have the answer.  When it comes to health, in the age-old battle of nature versus nurture… It's a draw.

University of Queensland research fellow Dr Beben Benyamin worked with scholars at the VU University of Amsterdam to review almost every twin study completed globally in the past 50 years.

After analysing studies of more than 14.5 million twin pairs across 17,804 traits from 2748 publications, they found variation for human traits and diseases was 49 per cent genetic (nature), and 51 per cent due to environmental factors (nurture).

The Queensland Brain Institute researcher said the draw was expected but he was pleased to be able to put a number on the variation and surprised by how similar an influence each aspect had.

"Most of the reviews have been for specific traits, like people are interested in studying one particular disease and review all the twin studies for one disease," he said.  "But this is I think is the first one to review everything about all disease and all twin studies that are available at the moment."

The influence of nature and nurture is actually a complex interplay rather than a simple either/or and is far from equal across all traits and diseases.

The risk for bipolar disorder was about 70 per cent due to genetics and 30 per cent due to environmental factors, Dr Benyamin found.

SOURCE

Black Brain, White Brain?

There came out recently a book called Black Brain, White Brain -- by  Gavin Evans.  It seems to have got some acclaim so I thought I might say a bit about it.  That task seems to be facilitated by an article by Evans under the same heading which appeared just over a month ago.  The article seems to summarize the main points of the book and thus spares me the time of reading the book.  But if there are things in the book which undermine any of the things I day below, I would be delighted to hear of it.

The main point of the book seems to be an accusation that it is racist to discuss the black/white IQ gap.  And like all other efforts in that direction that I know of it does a lot of huffing and puffing and declaring things obvious rather than providing proof of them.  The abusive and intemperate writing by Evans may be judged by his reference to "racist science that has been spewing out of the computers". Do computers spew? His use of abusive language like that is certainly a strong indication that he has a weak case that he is trying to cover up. "fester" and "dangerous" are other emotive words he uses.  Abuse in lieu of facts is a very familiar Leftist modus operandi.  And a few of Evans's  assertions do seem to be simply wrong.

And in the best Leftist style, his writing is almost entirely an appeal to authority.  Quite illogically, he thinks that because other people have declared something wrong then it must be wrong.  That many people have declared genetically-oriented treatments of the black/white IQ gap to be wrong and mistaken proves nothing at all.  It simply shows that most academics are Leftist.  For Evans to have written in any sort of scholarly way, he would have to list the main points where the genetic writers were found to be in error.  He does not do that.

He seems to think that he has made a great point by saying that no one gene for IQ  has been discovered.  So what?  IQ researchers have for decades accepted with perfect calm that  IQ is polygenetic.  Whether one gene or many is behind a difference may make research more or less difficult but it does not take away from the fact that the difference is genetic. And the genes that do contribute to IQ differences are being discovered all the time.  I must make a list of the studies concerned some time. I have noted quite a few on this blog.

He then goes on to claim that intelligence has not evolved for 100,000 years.  That completely ignores the work of Bruce Lahn, who showed a major evolutionary change in brain size about 5,000 years ago, a change which coincided with the birth of civilization and which is almost unknown in Africa. Pesky!

Another claim by Evans:  "Other studies have also shown that the IQs of children adopted into middle class homes rise significantly and that these increases can persist into adulthood".  He is right about the first part but wrong about the second part. Manipulations of the environment can improve IQ scores in childhood and even into the teens but by about age 30, all those improvements are lost.  By age 30 most environmental influences have washed out and the genetic endowment comes to the fore.

And then Evans gets on to the good ol' Flynn effect. So much has been written about that that I hesitate to write any more but in summary, the Flynn effect seems to be an artifact of increasing years of schooling and the test sophistication that engenders.  On important IQ subtests -- such as vocabulary -- where being test-wise does not help -- there has been very little movement in scores.  And in some advanced countries -- such as Nederland -- the rise has petered out, as one would expect if it was just a one-time artifact that had approached an asymptote (maximum value).

Finally, I am amazed by his assertion that "black American IQs are rising at a faster rate than those of white Americans".  I know of no evidence for that.  In fact, on some indices, the black/white gap is increasing.  So I guess I will have to "fester" away in my conclusion that there are real and inborn differences between the average IQs of blacks and whites.

And let's not have the old nonsense that IQ tests measure something limited and mysterious.  They measure general problem-solving ability, which is why researchers tend to use the term 'g' instead of 'IQ'.

And I may note that my view of IQ is no longer academically marginalized stuff at all. I don't quite know whether to be pleased or disappointed but it seems that mainstream psychology is catching up with what psychometricians such as myself have been saying for years: That IQ is highly general, highly central, highly hereditary and of overwhelming importance in determining people's life-chances. Not so long ago any claim to that effect would be very marginal within psychology and would expose anyone making it to all sorts of nasty accusations.

But you can now read it all not in some obscure academic journal or some Rightist source but in a 2004 issue (vol. 86 no. 1) of the American Psychological Association's most widely-circulated journal -- the Journal of Personality and Social Psychology.

Article after article there sets out the importance of IQ. And for social psychologists to be taking an interest in such evidence is really amazing. Psychometricians have known all that stuff for years. It is the social psychologists who have been most resistant to such ideas.  I guess that even an organization as Leftist as the American Psychological Association has to come to terms with the evidence eventually.

And note that the APA conceded some time ago that "African American IQ scores have long averaged about 15 points below those of Whites".  15 points is one standard deviation, which is a huge difference -- accounting for 34% of the distribution.  So it looks like I've got a lot of company in my "festering", as Evans calls it. Evans is fighting a lost battle.

Will organic milk shrink your baby's brain?

There is no doubt that iodine deficiency has a disastrous effect on infant IQ so health freaks who avoid salt are already skating on thin ice -- since iodized table salt is the main source of iodine in a Western diet.  But health freaks are usually also devotees of everything "organic", so the warning below addresses a serious concern for them.  Their children are doubly at risk

Pregnant women and breastfeeding mothers who drink organic milk may be putting their child’s health at risk, scientists claim.  They say it contains a third less iodine than normal milk – which could affect infant brain growth and intelligence later in life.

UHT longlife milk was also found to have similarly low levels of the mineral, academics from Reading University found.

Because milk is the main source of iodine in the British diet – providing 40 per cent of the average daily intake – switching to organic may have a significant impact on health, they warn.

Organic milk is often drunk for its supposed health benefits, with claims that it contains omega-3 fatty acids that are good for the heart. And in response to environmental and animal welfare concerns, the sector is growing.

But researchers said that because organic farmers do not give their cows as many artificial supplements the milk lacks iodine, which is important for the healthy development of babies in the womb and in their first months of life.

The mineral is thought to have a major impact on the formation of the brain, with repercussions for IQ and school success later in life.

SOURCE