The idea that some families are programmed to produce son after son, while others will have only daughters, may not be a myth. A man’s tendency to father sons could be influenced by his genes, research suggests.
A study by Corry Gellatly, of the University of Newcastle upon Tyne, shows that men who have many brothers are more likely to have sons themselves. One example is Alan Osmond, of the pop-singing brothers, who has eight sons. The research, published in Evolutionary Biology, studied 927 family trees from North America and Europe, which date back to 1600. “The study showed that whether you’re likely to have a boy or a girl is inherited,” Mr Gellatly said.
He suggested that an undiscovered gene could also explain why more boys than usual were born after both world wars. Families with multiple sons would have been more likely to see at least one survive, he said, and those sons would in turn have been more likely to father boys.