Depending on which area of the country you are from, you may not know that Norfolk has a reputation for inbreeding which can result in low IQ and physical deformity.
Hence the Norfolk greeting of "Give me six!".
Baseless rumour these days, but possibly some basis when the extensive fenlands made travel very difficult and led to small, isolated communities. Before the Dutch came and drained them.
See
https://www.discovernorfolk.co.uk/story/history-of-the-fens-81/ and also
http://www.englishmonarchs.co.uk/normans_14.html.
" Ely at that time was an island in the fenland, William was foiled on three occasions by Hereward in his attempts to build a causeway across the impassable marshes, known as the Aldreth Causeway. However, during William's first attack the weight of the troops on the bridge was so great that the causeway sank and many soldiers drowned."
Fascinating subject, diabetes.