HUMAN intelligence cannot be explained by the size of the brain's frontal lobes, according to a study which involved North-East researchers

Research into the comparative size of the frontal lobes in humans and other species has determined that they are not - as previously thought - disproportionately enlarged relative to other areas of the brain.

The study concluded that the size of frontal lobes cannot solely account for humans' superior cognitive abilities.

The study by Durham and Reading universities suggests that supposedly more 'primitive' areas, such as the cerebellum, were equally important in the expansion of the human brain. These areas may therefore play unexpectedly important roles in human cognition and its disorders, such as autism and dyslexia, say the researchers.

The study is published in the Proceedings of the National Academy of Sciences.

Lead author Professor Robert Barton from the department of anthropology at Durham University, said: "This means that areas traditionally considered to be more primitive were just as important during our evolution. These other areas should now get more attention. In fact there is already some evidence that damage to the cerebellum, for example, is a factor in disorders such as autism and dyslexia."

The Durham and Reading researchers, funded by The Leverhulme Trust, analysed data sets from previous animal and human studies and found consistent results across all their data.