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Researchers have found that up to half of our intelligence (or lack of it) is inherited.

They examined the blood of more than 3,500 people from England and Scotland for half a million genetic markers – tiny changes in their DNA.

Researchers say that while education and lifespan can contribute to your brain power, genes play a huge part

Analysis of these results and those of intelligence tests completed by the study’s participants revealed that 40 per cent of the differences in ‘crystallised-type intelligence’, the ability to acquire knowledge and skills over the years, were in the genes.

So-called fluid-type intelligence, the ability to reason and think abstractly under pressure, was governed by genetics to an even greater extent.

Some 51 per cent of a person’s ability to ‘think outside the box’ is down to DNA, the journal Molecular Psychiatry reports.

The research, made possible by a new type of genetic analysis pioneered by Peter Visscher of the Queensland Institute of Medical Research in Australia, points to numerous genes being involved.

Lead researcher Professor Ian Deary, of the University of Edinburgh, said: ‘Individual differences in intelligence are strongly associated with many important life outcomes, including educational and occupational attainments, income, health and lifespan.’

However, he added that the study’s results ‘unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation’.

He hopes to unlock the secrets of those whose brains age well, with a view to helping others stay sharp as they get older.

‘If we can find specific genetic contributions to people’s experience of cognitive ageing, this can suggest the mechanisms by which people differ,’ he said. ‘We are studying genetics to find out how things work.’

Professor Deary added that those dealt a poor hereditary hand should not act as if their fate is sealed, as it is possible for people to overcome their intellectual inheritance.

The research may explain why humans have advanced so much further than chimpanzees, despite their genetic similarity.

Simon Underdown, an anthropologist from Oxford Brookes University, said: ‘The devil is clearly in the detail.

It is not necessarily that we share the same genes – it is how they interact with other genes that controls intelligence.

‘Human intelligence is a stunning product of our evolution and this brilliantly demonstrates that the genetic basis for our intelligence is not the result of a simple mutation in a single gene.

‘It moves away from the old-fashioned idea that there may be a gene or a couple of genes for intelligence.It looks as if there are lots and lots of genes across the chromosomes.’