PEOPLE AND PLACES: THE BRAIN CONNECTIONS VS THE FAMILY CONNECTIONS

THE BRAIN CONNECTIONS VS THE FAMILY CONNECTIONS

For a long time it was thought that the brain was a mass of tangled wires, but researchers recently found that its fibers are actually set up like a chess board, crossing at right-angles.
What’s more, this grid structure has now been revealed in amazing detail as part of a brain imaging study by a new state-of-the-art magnetic resonance imaging (MRI) scanner.
Van Wedeen, of Massachusetts General Hospital (MGH), who led study, said: ‘Far from being just a tangle of wires, the brain's connections turn out to be more like ribbon cables - folding 2D sheets of parallel neuronal fibers that cross paths at right angles, like the warp and weft of a fabric.

Curvature in this image of a whole human brain turns out to be folding of 2D sheets of parallel neuronal fibers that cross paths at right angles
‘This grid structure is continuous and consistent at all scales and across humans and other primate species.’
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Thomas R Insel, the director of the National Institute for Mental Health, said: ‘Getting a high-resolution wiring diagram of our brains is a landmark in human neuroanatomy.
‘This new technology may reveal individual differences in brain connections that could aid diagnosis and treatment of brain disorders.’
The Connectom MRI scanner was installed at MGH last year and can visualise the networks of criss-crossing fibers – by which different parts of the brain communicate with each other – in 10-fold higher detail than conventional scanners, according to Wedeen.
He said: ‘This one-of-a-kind instrument is bringing into sharper focus an astonishingly simple architecture that makes sense in light of how the brain grows. The wiring of the mature brain appears to mirror three primal pathways established in embryonic development.’
As the brain gets wired up in early development, its connections form along perpendicular pathways, running horizontally, vertically and transversely.

Revelation: The fabric-like 3D grid structure of connections in a monkey brain
This grid structure appears to guide connectivity like lane markers on a highway, which would limit options for growing nerve fibers to change direction during development.
If they can turn in just four directions: left, right, up or down, this may enforce a more efficient, orderly way for the fibers to find their proper connections – and for the structure to adapt through evolution, suggest the researchers.
Obtaining detailed images of these pathways in human brain has long eluded researchers, in part, because the human cortex, or outer mantle, develops many folds, nooks and crannies that obscure the structure of its connections.
Although studies using chemical tracers in neural tracts of animal brains yielded hints of a grid structure, such invasive techniques could not be used in humans.
It’s thought that with previous technology 25 per cent of the brain’s structure was revealed – the new scanner shows 75 per cent of it.
‘Before, we had just driving directions. Now, we have a map showing how all the highways and byways are interconnected,’ said Wedeen. ‘Brain wiring is not like the wiring in your basement, where it just needs to connect the right endpoints. Rather, the grid is the language of the brain and wiring and re-wiring work by modifying it.’
Results of the study appear in the journal Science.

A father’s brains could mean more to his son’s success than his money because of the importance of teaching a good worth ethic and the ability to study, a new study claims.
Although sons of fathers with high incomes tend to end up with higher than average incomes themselves, the findings show that it’s not just the cash that helps a son on his way.
According to a study recently published in the Journal of Political Economy, human capital passed from father to son - perhaps in the form of smarts, advice, work ethic, or some other intangible - could be more important to a son’s success than the size of daddy’s paycheck.

One day, son, all my intangible human capital will be yours... New research shows that a father's brains and work ethic can have a big impact on his son's earnings
It found that these human intangibles account for nearly two-thirds of a the overall relationship between the father's income and the son's, and that income had only a weak influence.
David Sims, economics professor at Brigham Young University, who led the study, said: 'We know there’s a correlation between fathers’ income and sons’. What's got less attention is the mechanism.'
'We wanted to see if the intergenerational income correlation is due to money - what we can buy for our kids - or if human capital attributes passed from father to son play a role as well.'

The report says that the problem is that separating the two inputs is tricky. On average, fathers with higher human capital endowments also tend to have higher incomes, so it’s hard to tell which factor is doing what. Professor Sims and his colleagues used a statistical model and a rich dataset to try to disentangle the two.
The authors’ methodology builds on the following thought experiment. Take two smart, similarly skilled and educated fathers. Say one lived in a town with a robust labour market and he had a big salary. The other father wasn’t so lucky. He lived in a town with a depressed labour market, and had much lower earnings despite his comparable human capital.
If money is the only thing that matters in the intergenerational transfer of income, then we’d expect that the son of the lucky father would end up with a higher income than the son of the unlucky father.
However, if human capital matters, the two sons may end up with more similar incomes.

It's all down to the parenting: The study showed that the father's human capital was much more important than wealth as a determiner of a son's future income
To test this idea, the researchers used remarkably detailed government administrative data on a large sample of Swedish fathers with sons born between 1950 and 1965.
The data included salary information for fathers and sons as well as clues about fathers’ human capital in the form of education levels and the nature of their occupations. Fathers with more education or those who work in jobs that require specialised skills are considered to have higher human capital endowments that could be passed to sons.
First, Sims and his colleagues looked for a raw correlation between fathers’ incomes and their sons’, which, as expected, was quite strong.
Then they employed a statistical methodology to isolate differences in fathers’ income due to something other than human capital, like in the example of similar fathers who worked in differing labour market conditions.
If the income correlation weakens for fathers and sons in these types of situations, the researchers could conclude that money isn’t the only thing that matters.
And that’s exactly what the study found. Income differences not related to a father’s human capital were weaker predictors of a son’s income. In other words, human capital matters.
'We can conclude that, for the men in our dataset, differing human capital endowments passed from father to son account for about two-thirds of the overall intergenerational income relationship,' Professor Sims said.
'We don’t offer a final answer here, but we do offer some boundary conditions and present a methodology that could help unravel the question.'

Brains donated following the death of three men will serve as baseline for interactive map

Scientists have created a comprehensive and interactive 'atlas of the brain' - and have opened it up to the entire internet to help in neurological research.

The atlas was created from the scans of three 'clinically unremarkable' brains - donated following the deaths of a 24-year-old and 39-year-old man, and half a brain from a third man.

A 3D rendering by the Allen Institute shows genes within the internal structure of the brain: Blue dots show low gene activity, red dots show high activity

There are more than 20,000 genes in the human genome, and around 84 per cent of them are active within the human brain.

To create the atlas, the scientists first of all scanned the brains, before chopping them into small pieces. For each piece, they scanned for and recorded the activity levels of the 20,000 genes.

When the scans of the two complete brains were compared to each other, the team found what they believe is a 'genetic blueprint' for how the brain may be mapped out - with so many similarities in gene placement and usage.

Their next aim is to scan a female brain to see how it compares to the other gender.

Mapping: Scientists spent four years on the $50m project to link a number of genes with the site on the brain that they correspond with

Professor Seth Grant of Edinburgh University, who helped create the map, said: 'The human brain is the most complex structure known to mankind and one of the greatest challenges in modern biology is to understand how it is built and organised.

'This allows us for the first time to overlay the human genome on to the human brain.

'It gives us essentially the Rosetta stone for understanding the link between the genome and the brain, and gives us a path forward to decoding how genetic disorders impact and produce brain disease.'

Brain matter: Scientists hope that by creating a digital map of the brain they will be able to better understand a range on conditions and how they develop

It is commonly-known that people use each side of the brain for different purposes, with 'creative' tasks coming from the right side of the brain. However researchers saw no such divide within genes, suggesting another mechanism controls how we handle different tasks.

With the map available to the public at http://human.brain-map.org, it is hoped that other researchers can compare their gene research against the atlas, improving our knowledge of our most vital organ.

Institutes such as Max Planck Institute for Psycholinguistics have already announced they will use the map to help research genes and brain symmetry. More than other 4,000 researchers have already used the tool.

Brain scans which establish how well different regions of your brain are detected may be able to predict how intelligent you are, a new study claims.

Research suggests that 10 per cent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex to the rest of the brain.

The findings, published in the Journal of Neuroscience, establish 'global brain connectivity' as a new approach for understanding how human intelligence relates to physiology.

Well connected: Ten per cent of intelligence could be explained by the strength of neural pathways connecting the left lateral prefrontal cortex

'Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,' said Michael Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University and lead author of the study.

He says the research is the first to provide compelling evidence that neural connections between the lateral prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence.

'This study suggests that part of what it means to be intelligent is having a lateral prefrontal cortex that does its job well; and part of what that means is that it can effectively communicate with the rest of the brain,' added study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine.

One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a 'flexible hub' that uses its connectivity to monitor and influence other brain regions.

'There is evidence that the lateral prefrontal cortex is the brain region that "remembers" the goals and instructions that help you keep doing what is needed when you're working on a task,' said Prof Cole.

'So it makes sense that having this region communicating effectively with other regions (the "perceivers" and "doers" of the brain) would help you to accomplish tasks intelligently.'

While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand. This happens in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

'We're suggesting that the lateral prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn't do this alone,' said Prof Cole.

Brain scans: The findings are based on an analysis of functional magnetic resonance (fMRI) brain images

The findings are based on an analysis of functional magnetic resonance (fMRI) brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.

Previous findings relating lateral prefrontal cortex activity to challenging task performance were supported. Connectivity was then assessed while participants rested, and their performance on additional tests of fluid intelligence and cognitive control collected outside the brain scanner was associated with the estimated connectivity.

Results indicate that levels of global brain connectivity with a part of the left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.

Although much remains to be learned about how these neural connections contribute to fluid intelligence, new models of brain function suggested by this research could have important implications for the future understanding — and perhaps augmentation — of human intelligence.

The findings also may offer new avenues for understanding how breakdowns in global brain connectivity contribute to the profound cognitive control deficits seen in schizophrenia and other mental illnesses, Prof Cole suggests.

It ISN'T 'who you know': Coming from a well-connected family helps get a job - but success is down to your own brain power

Connections mean a higher first wage - but brain power soon overtakes
Over time, intelligence is factor that dictates earnings and success
Coming from a wealthy background has little impact on lifetime earnings

Being able to call on the 'old boy's network' helps you get your 'foot in the door' - but has no impact on your success.

Having 'good connections' DO change your likelihood of being offered a high wage when you start - but have no impact on your eventual wage.

The provocative study is sure to infuriate those angered by wealthy groups such as Oxford's upper-crust Bullingdon Club, of which both David Cameron and Boris Johnson were members.

Oxford's Bullingdon Club today: The provocative study is sure to infuriate those angered by societies such as Oxford's upper-crust Bullingdon Club, of which both David Cameron and Boris Johnson were members

The speed of your 'rise through the ranks' is dictated largely by your own intelligence.

The study, of 2,868 Americans from 1979 through 2004, monitored earnings and promotions over the course of 25 years.

Scores were used to assess the 'socio-economic background' - wealth and connections - and standard Army intelligence tests used to assess intelligence.

Profesor Yoav Ganzach of the University of Tel Aviv says that these findings, published in the journal Intelligence, have a positive message for those who can’t rely on nepotism for their first job placements.

‘Your family can help you launch your career and you do get an advantage, but it doesn’t help you progress. And once you start working, you can go wherever your abilities take you,’ he says.

When intelligence and socio-economic background (SEB) are pitted directly against one another, intelligence is a more accurate predictor of future career success, he asserts.

Eton Schoolboys in uniform: Many of Britain's top politicians attended the schoool

Taking into account each participant’s rate of advancement throughout the career arc, the data confirmed that while both intelligence and SEB impacted entry-level wages, only intelligence had an influence on the pace of pay increases throughout the years.

When looking at rates of advancement, intelligence won out over SEB in terms of career advancement.

How Rain Man's brain REALLY worked: New scans reveal the makeup of patients with similar condition

Researchers use brain scans and network analysis to map the brains of patients with agenesis of the corpus callosum
People with this condition, which affected real-life Rain Man Kim Peek, are lacking the neurological structure which connects the left and right brains
Scientists hope their findings will shed light on why some people with the condition develop autism and others do not

New research using brain scans sheds light on the way that the Rain Man's remarkable brain worked. Scientists at UC San Francisco and UC Berkeley combined hospital MRIs with a mathematical tool called network analysis to make 3D maps of the brains of seven adults who have the same condition. These 'structural connectome' maps, described in the upcoming April 15 issue of the journal Neuroimage, reveal new details about the condition known as agenesis of the corpus callosum.

Immortalised on the silver screen: Tom Cruise, left, and Dustin Hoffman, right, in a frame from the Hollywood film Rain Man, which was based on Kim Peek, a famous sufferer of agenesis of the corpus callosum

This is where genetic malformations leave patients without a corpus callosum, the neurological structure that connects the left and right sides of the brain.

That condition is one of the top genetic causes of autism and was part of the mysterious brain physiology of Laurence Kim Peek, the remarkable savant portrayed by Dustin Hoffman in the 1987 movie Rain Man.

Mr Peek, from Utah, who died in 2009 aged 58, was known as a 'megasavant' for his exceptional memory, but he also experienced significant social difficulties. He could speed through a book in about an hour and remember almost everything he had read, memorising vast amounts of information in subjects ranging from history and literature, geography and numbers to sports, music and dates.

But while his amazing memory emerged as early as 16 months, he could not walk until the age of four, could not button up his own shirts and scored a below-average 87 on general IQ tests.

While some people born with agenesis of the corpus callosum are of normal intelligence and do not have any obvious signs of neurologic disease, approximately 40 per cent of people with the condition are at high risk for autism.

Megasavant: Kim Peek, who in 2009, could speed through a book in about an hour and remember almost everything he had read but could not button up his own shirts and scored a below-average 87 on general IQ tests

Given this, the work is a step toward finding better ways to image the brains of people with the condition, said Dr Pratik Mukherjee, a professor of radiology and biomedical imaging at UCSF.

Understanding how brain connectivity varies from person to person may help researchers identify imaging biomarkers for autism to help diagnose it and manage care for individuals.

Currently autism is diagnosed and assessed based on cognitive tests, such as those involving stacking blocks and looking at pictures on flip cards.

While the new work falls short of a quantitative measure doctors could use instead of cognitive testing, it does offer a proof-of-principle that this novel technique may shed light on neurodevelopment disorders.

'Because you are looking at the whole brain at the network level, you can do new types of analysis to find what's abnormal,' Dr Mukherjee said.

$Different brain structures: Example midline sagittal and coronal colour fractional anisotropy (FA) images for a control subject with a normal brain and a patient suffering from agenesis of the corpus callosum$

Different brain structures: Example midline sagittal and coronal colour fractional anisotropy (FA) images for a control subject with a normal brain and a patient suffering from agenesis of the corpus callosum

Agenesis of the corpus callosum can arise if individuals are born missing DNA from chromosome 16 and often leads to autism.

Scientists have long puzzled over what the link is between this disorder and the autistic brain, especially since not all people with this malformation develop autism, said Dr Elliott Sherr, professor of neurology and genetics.

Doctors believe this is because the brain has a rich capacity for rewiring in alternative ways.

Pursuing this question, Dr Mukherjee and Dr Sherr turned to MRI and the mathematical technique of network analysis, which has previously been used by urban planners to optimise the timing of traffic lights to speed traffic.

The researchers believe their study is the first to apply network analysis to brain mapping for a genetic cause of autism.

Network analysis: These structural connectome maps show the differences in brain wiring between three subjects with agenesis of the corpus callosum and three subjects with normal brains

The brain offers a significantly complicated challenge for analysis because, unlike the streets of a given city, the brain has hundreds of billions of neurons.

Many of these make tens of thousands of connections to each other, making its level of connectivity highly complex.

By comparing the seven rain man-like brains to those of 11 people without this malformation, the scientists determined how particular structures called the cingulate bundles were smaller and the neurons within these bundles were less connected to others in the brain.

They also found that the network topology of the brain was more variable in people with agenesis of the corpus callosum than in people without the malformation.

Dr Mukherjee and Dr Sherr are senior authors on the study, which is already available online.

The Human Connectome Project released high quality images of the brain
They say it will have a 'major impact' on our understanding of the organ
The project aims to make advanced brain images freely available

Scientists have released high quality images of the brain that they claim will have a ‘major impact’ on our understanding of the organ. Following a five year project involving more than 100 researchers from ten institutions, the experts have released the data that they hope will enable the exploration of the relationships between brain circuits and an individual's behaviour. The Human Connectome Project, which involves scientists across Europe and the USA, aims to collect data using advanced brain imaging methods, and to make the data freely available so that scientists worldwide can make further discoveries about brain circuitry.

A map of average 'functional connectivity' in human cerebral cortex

An MRI scan of the brain at rest

The initial data release includes brain imaging scans plus behavioural information — individual differences in personality, cognitive capabilities, emotional characteristics and perceptual function — obtained from 68 healthy adult volunteers. It is particularly notable because the new data has much higher resolution in space and time than data obtained by conventional brain scans.Over the next few years the number of people studied will increase until the researchers reach their final target of 1,200. The Human Connectome Project consortium is led by Dr David Van Essen, Alumni Endowed Professor at Washington University School of Medicine in St. Louis.

One of the 'connection maps' created by the team, which shows pathways in the brain of volunteers

The project will publish all of its data online and make it accessible for researchers

He said: ‘By making this unique data set available now, and continuing with regular data releases every quarter, the Human Connectome Project is enabling the scientific community to immediately begin exploring relationships between brain circuits and individual behaviour. ‘The HCP will have a major impact on our understanding of the healthy adult human brain, and it will set the stage for future projects that examine changes in brain circuits underlying the wide variety of brain disorders afflicting humankind.’

A composite of the scans of 20 individuals. Regions in yellow and red are linked to the parietal lobe of the brain's right hemisphere

Yellow and red regions are activated by a task involving listening to stories, whereas green and blue regions are more strongly activated by a task involving arithmetic calculations

The data set includes information about brain connectivity in each individual, using two distinct magnetic resonance imaging (MRI) approaches.

One is based on spontaneous fluctuations in functional MRI signals that occur in a complex pattern in space and time throughout the gray matter of the brain.

Another, called diffusion imaging, provides information about the long-distance ‘wiring’ – the anatomical pathways traversing the brain’s white matter.

Brain activations in the brain's grey matter. Yellow and red regions are activated when subjects view human faces

Each subject was also scanned while performing a variety of tasks within the scanner, thereby providing extensive information about brain activation patterns.

Behavioural data using a variety of tests performed outside the scanner are being released along with the scan data for each subject.

The subjects are drawn from families that include siblings, some of whom are twins. This will enable studies of the heritability of brain circuits.

Dr Daniel Marcus, assistant professor of radiology and director of the Neuroinformatics Research Group at Washington University School of Medicine, said: ‘The Human Connectome Project represents a major advance in sharing brain imaging data in ways that will accelerate the pace of discovery about the human brain in health and disease.’

Some people will never learn – and now scientists think they know why. People who keep repeating the same mistakes have less active brains. The study at Goldsmiths, University of London, is one of the first to try and work out why some people are better at learning from their mistakes than others.

The team studied whether participants were able to listen to feedback and improve their performance on a series of tests.

The researchers analysed electrical brain responses, and identified some people, called high learners, and shown on the left, could learn from mistakes better than others, dubbed low learners

They found that the results varied significantly.

The research, led by Professor Joydeep Bhattacharya in the Department of Psychology at Goldsmiths, examined what it is about the brain that defines someone as a 'good learner' from those who do not learn from their mistakes.

'We are always told how important it is to learn from our errors, our experiences, but is this true?,' he said.

'If so, then why do we all not learn from our experiences in the same way? It seems some people rarely do, even when they were informed of their errors in repeated attempts. 'This study presents a first tantalising insight into how our brain processes the performance feedback and what it does with this information, whether to learn from it or to brush it aside.'

The study, published in a recent issue of the Journal of Neuroscience, investigated brainwave patterns of 36 healthy human volunteers performing a simple time estimation task.

Researchers asked the participants to estimate a time interval of 1.7 seconds and provided feedback on their errors.

The participants were then measured to see whether they incorporated the feedback to improve their future performances.

'Good learners', who were successful in incorporating the feedback information in adjusting their future performance, presented increased brain responses as fast as 200 milliseconds after the feedback on their performance was presented on a computer screen.

Researchers say that different people learn in very different ways - with 'high learners' far better at learning from their mistakes

This brain response was weaker in the poor learners who did not learn the task well and who showed decreased responses to their performance errors.

The researchers further found that the good learners showed increased communication between brain areas involved with performance monitoring and some motor processes.

Caroline Di Bernardi Luft, one of the research paper's co-authors from the Federal University of Santa Catarina, commented: 'Good learners used the feedback not only to check their past performance, but also to adjust their next performance accordingly.' The brain responses correlated highly with how well the volunteers learned this simple task over the course of the experiment, and how good they were at maintaining the learned skill without any guiding feedback. Babies born up to three months premature can recognise different syllables in human speech, say scientists.

A study showed similarities in the way the brain processes language in the new-borns and adults - including specific neurological reactions to changes from the 'ba' to 'ga' sound and to a male to female voices.

Professor Fabrice Wallois, of Picardie University in Amiens, France, said the findings suggest that early in the development of the brain it begins to decipher distinct sounds or 'phonemes'.

The study showed similarities in the way the brain processes language in the new-borns and adults - including specific neurological reactions to changes from the "ba" to "ga" sound and to a male to female voices.

HOW THEY DID IT

Using bedside functional optical imaging, Fabrice Wallois and colleagues scanned 12 sleeping 28-32-week gestation age pre-term infants.

This is the earliest age at which cortical responses to external stimuli can be recorded. He said as early as three months before birth a baby's brain establishes neural functions that help decipher human speech. At birth children can discriminate some syllables and recognise human speech but how these immature brain cells process it remains unclear. Using powerful non-invasive scanners Prof Wallois and colleagues analysed 12 sleeping premature infants born after 28 to 32 weeks while playing voice recordings. This is the earliest age for neuronal responses to external stimuli and Prof Wallois found the premature brain can perceive differences in syllables. In addition although the tests produced responses in the right frontal region of the brain - the first part of the brain to form - syllabic changes also sparked responses in the left hemisphere. This suggests certain linguistic brain areas exhibit a sophisticated degree of organisation as early as three months prior to full term.

Prof Wallois said: 'We observed several points of similarity with the adult linguistic network.

The research gives a new insight into the way mothers communicate with their babies - and how language skills develop. 'First, whereas syllables elicited larger right than left responses, the posterior temporal region escaped this general pattern, showing faster and more sustained responses over the left than over the right hemisphere. 'Second, discrimination responses to a change of phoneme (ba vs. ga) and a change of human voice (male vs. female) were already present and involved inferior frontal areas, even in the youngest infants. 'Third, whereas both types of changes elicited responses in the right frontal region, the left frontal region only reacted to a change of phoneme.'These results demonstrate a sophisticated organisation of areas at the very onset of cortical circuitry - three months before term. 'They emphasise the influence of innate factors on regions involved in linguistic processing and social communication in humans.'The study is published in Proceedings of the National Academy of Sciences.

Thank your parents if you're smart: Up to 40% of a child's intelligence is inherited, researchers claim

New estimate is lower than those given by previous studies. Researchers analysed DNA and IQ test results from 18,000 children. They suggest a range of genes may affect intelligence cumulatively

It's all in the genes: A new study shows that up to 40 per cent of a child's intelligence is passed down from the parents. Up to 40 per cent of a child's intelligence is passed down from the parents, according to a new study. The finding from the largest ever genetic study of childhood intelligence adds yet more fuel to the debate over whether intelligence is a product of nature or nurture. Using genetic data and IQ scores of thousands of children from four countries, researchers from the University of Queensland found attempted to separate out the environmental effects. They found that between 20 and 40 per cent of the variation in childhood IQ is due to genetic factors, less than the 40 to 50 per cent suggested by previous research. Dr Beben Benyamin, from the University of Queensland, told ABC: 'This estimate from DNA information is lower than family studies, but it is consistent with the conclusion childhood intelligence is heritable.' Dr Benyamin and his colleagues analysed DNA samples from 18,000 children aged six to 18 from Australia, the Netherlands, the UK and the U.S, along with their IQ scores.

They looked for any correlations between patterns of differences in the youngsters' DNA with patterns of differences in their IQ. Findings showed that a gene known as FNBP1L was significantly linked to childhood intelligence. The same gene had previously been shown to be the most significant gene in predicting adult intelligence. Usually when looking at how genetic factors influence individual traits scientists prefer to look for gene variants known as single-nucleotide polymorphisms (SNPs), as these give more precise genetic information, ABC reported. However, Professor Benyamin said, the study did not find any single SNP gene variant that could strongly predict childhood intelligence.

Nature or nurture? It could be many genes that contribute to intelligence in children, with each having a small, but cumulative effect, the study suggests. 'But when we looked at the combined effect of all SNPs we can estimate the contribution of genetics to be about 20 to 40 per cent of the difference in IQ,' he said. That means it could be many genes that contribute to intelligence in children, with each having a small, but cumulative effect, the study suggests. Understanding the factors influencing intelligence is important since IQ is a good predictor for lifespan, educational achievement and adult income, said Professor Benyamin. The findings may also help researchers to better understand intellectual disability, he added.