Jokes told in public houses in the 1950s would often start with the words: "There was an Englishman, a Welshman, an Irishman, and a Scotsman." Professor Dr. Sigmund Freud's book on the Psychopathology of Everyday Life (page 161 of the 1938 Pelican edition) explains what is going on by pointing to the following quotation:

Goethe said of Lichtenberg:
"Where he cracks a joke, there lies a concealed problem."

Underlying all the "There was an Englishman, a Welshman, an Irishman and a Scotsman" jokes was a frantic bid at relieving the tensions that are part and parcel of living under a multi-national state. It was only thanks to the mutal tolerance of Englishmen, Welshmen, Irishmen and Scotsmen that the United Kingdom had survived at all.
Scotsmen were strangely absent from the old man's drinking circles, and this could have been partly because of the tyranny of distance. Scotland seemed a heck of a long way from Somerset. Getting from South Wales to Somerset only took a couple of hours. Even Dublin was just an overnight ferry trip and a train ride away. There was a feeling that Glasgow was a place just to the south of Iceland.
Although the "There was an Englishman, a Welshman, an Irishman, and a Scotsman" jokes always seemed to be well received, the laughter which followed them always felt a shade contrived. As could also be the case with some of the passages of Professor Dr. Sigmund's Freud's famous book, it could be impossible to make heads or tales of what they really meant.