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