Even the most dedicated social scientist might find it difficult to determine the origins of this well-established and quite widespread British tradition. A quick trawl of the nation's regional press reveals quite serious altercations in Warrington, Southampton, Henley, High Wycombe and Cardiff mentioned over the past few weeks.
Obviously drink is a factor. But why the kebab shop should be the focus for violence – rather than, say, the chippy or burger van – is less clear. Perhaps it is something to do with the extra chilli sauce that inflames passions. Or it could be the often-chaotic queuing system. Or the contents of a sometimes-untidy sandwich spilling out on to a stranger's outfit.
In any case, a sizeable proportion of the British people will have witnessed such a scrap, or at least stepped over bloodied city-centre pavements strewn with bits of kebab, squashed chips and the odd abandoned stiletto the following morning. Reason enough for this ritual to qualify as a Minor British Institution.