In a blow to dads everywhere, children apparently inherit all their intelligence from their mums, according to scientists.
Due to intelligence genes being carried on the X chromosome, women are more likely to pass them on as they have two, compare to one for men.
And researchers in Glasgow believe genes for advanced cognitive functions which are inherited from the father may be automatically deactivated - meaning they have no effect on their children.
Tests on mice found that those given extra maternal genes developed larger heads and brains but with smaller bodies, while those with added paternal genes had small brains and large bodies.
Genetics: Men have less chromosomes that carry intelligence genes than women (Rex/posed by models)
The scientists extended their study to humans and after interviewing 12,685 people between the ages of 14 and 22 every year from 1994, concluded that that the best predictor of intelligence was the IQ of the mother.
But while genetics may play a part in intelligence, scientists added that environmental factor also play a large part.
Researchers at the University of Washington believe children who were supported emotionally have higher growth in the parts of the brain that are associated with memory, learning and stress response.
This strong bond is thought to give a child a sense of security which gives them confidence to solve problems.
Top pic: Rex/posed by models