A University of Leicester study finds that surnames ending in "son" came from northern England, while names ending in "s" came from the south.
They discovered that nearly 60 per cent of northerners in villages such as Crosby, Ravensworth and Patterdale had a "son" surname in the seventeenth century.
Dr Dave Postles, from the University of Leicester's English department, said: "Looking from the outside, it will be noticeable to people that the 'north' of England is a place where surnames ending in 'son' have predominated, although they have spread more widely now.
"Whereby somebody in the North would be called Williamson in the South they would be called William or Williams." [Link]