Why some people are smarter
Scientists have found why some people are smarter than others — because they have more efficient neural networks in their brains.world Updated: Apr 06, 2010 00:21 IST
Scientists have found why some people are smarter than others — because they have more efficient neural networks in their brains.
Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Centre in the Netherlands, found that smarter brains seem to have more efficient networks between neurons.
This means that it takes fewer steps to relay a message between different regions of the brain.
That could explain about a third of the variation in a population’s intelligence quotient (IQ), he said.
Another key factor is the insulating fatty sheath encasing neuron fibres, which affects the speed of electrical signals.
Paul Thompson at the University of California, Los Angeles, has found a correlation between IQ and the quality of the sheaths.
Many studies have estimated that genes contribute around 40 to 80 per cent to intelligence.
This wide range of estimates might have arisen because genes contribute more to IQ as we get older.
By comparing the intelligence of 11,000 pairs of twins, Robert Plomin of King’s College London found that at age 9, genes explain 40 per cent of the variation, but by 17 they account for roughly two-thirds.
This could perhaps be because genes affect how our brain rewires itself as we mature.