In the 19th century, poorer families living in cities in Europe had a higher rate of children who weren’t biologically related to their legal fathers. This is according to a genetic study that looked at how this rate differs for different socio-economic groups.
It is widely assumed many men aren’t the biological fathers of their children. The rate of extra-pair paternity, as this is called, has been claimed to be as high as 30 per cent today. “They look just like the milkman,” goes the popular joke that no parent finds funny.