Your family's genetic make-up may explain why your brain is sharp or dull, so says researchers.
Alex Fornito from the University Melbourne Neuropsychiatry Centre said the findings have a bearing on why some people are better at certain tasks than others and also the genetic basis of mental illnesses.
"The brain is an extraordinarily complex network of billions of nerve cells interconnected by trillions of fibres," Fornito was quoted as saying by The Journal of Neuroscience.
"The brain tries to maximize its bang-for-buck by striking a balance between making more connections to promote efficient communication and minimising the 'cost' or amount of wiring required to make these connections," he said, according to a Melbourne statement.
"Our findings indicate that this balance, called 'cost-efficiency', has a strong genetic basis.
"Ultimately, this research may help us uncover which specific genes are important in explaining differences in cognitive abilities, risk for mental illness and neurological diseases such as schizophrenia and Alzheimer's disease," said Fornito.
The research team, which included scientists from the Universities of Queensland and Cambridge in Britain, compared the brain scans of 38 identical and 26 non-identical twins from the Australian Twin Registry.