Microvariation in Dellys Arabic

There are plenty of factors that one naturally expects to condition linguistic variation: age, sex, location, class, ethnicity, religion - in short, any variable such that people are more likely to talk with those who match their value for it than with those who don't. Dellys offers clear examples of several of these:

• Age: There's an obvious gap between the generation born before Independence and those born since then, the latter having had much greater freedom of movement and access to media as well as education. Within my extended family, my father's generation all negate verbs indifferently with ma... ši ما...شي or ma... š ما...ش, whereas their children and grandchildren uniformly use only the latter. Similarly, the older generation use mazəlt مازلْت for "I am still...", conjugating it as a verb, while the younger ones consistently use mazalni مازالني; many of the older generation use -ayən ـاين for the dual (eg يوماين yumayən "two days"), while the younger generation all use -in ـين.
• Sex: Only women use the exclamation a məħħənti أ محّنتي "oh my goodness!"; only men, as far as I've noticed, use the quasi-expletive jədd جدّ "grandfather" (eg nəħħi jəddu نحّي جدّهُ, approximately "remove the damn thing"). In less integrated French loans, women of my generation or younger use a uvular R, whereas almost all men (and older women) substitute a trill ṛ; this sex differentiation is acquired well before the age of ten.
• Location: The most salient distinction at a local level is classic in Maghreb dialectology: urban (more or less pre-Hilalian) vs. rural (Hilalian). People from Dellys proper say qal قال "he said" and ṣab "he found"; people from the villages and small towns around it instead say gal and lga.

Such variation is easily understood. But a lot of variation I'm noticing seems to show no such patterning. Out of three brothers, fairly close together in age and all currently working in the same family business:

• Two have baš باش for "so that"; the third - unlike anyone else I know - uses li baš لي باش.
• All use lukan لوكان for "if (hypothetical)", but one also uses lakun لاكون and the other yakun ياكون.

Maybe this is somehow explained by their earlier backgrounds - the one who uses li baš لي باش and yakun ياكون had more education, perhaps he picked it up where he went to school, or where he used to work when he was younger? But there are many other variables like this. I similarly don't see any pattern to the choice between bəṛk برْك and kan كان for "only", or yəsħaq and yəsħaj يسحاج for "he needs", or yʊɣləq يُغلق and yəʕləq يعلق for "he closes", or (at least for older speakers)yəqdər يقدر and yənjəm ينجم for "he can". People of the same age and gender, living all their lives less than a kilometer from each other and sometimes even in the same household, consistently use one or the other. Presumably something must explain the difference, but it looks like it would require a pretty intensive social network analysis to find out...

This is actually fairly similar to what Nancy Dorian found for the Scots Gaelic of East Sutherland fisherfolk: "Surprises in Sutherland: Linguistic Variability amidst Social Uniformity". She observes that this kind of variation usually tends to be ignored: "Oftedal, my immediate predecessor in Gaelic dialect studies, noted that the Gaelic of his single source and that of the man’s wife differed in a number of respects, despite the fact that the two had grown up as next-door neighbors; but after noting the existence of such differences in an early footnote, he never referred to the wife’s Gaelic again." While Algerian Arabic is far from endangered, the two situations are not as different as you might think: in both cases, small towns were substantially expanded over the 19th century by rural refugees fleeing land confiscations and wider upheavals, and left to sort out the resulting mess of dialect variation among themselves without that much pressure towards standardization. Perhaps such variables would have correlated more clearly with speakers' background a century ago, and have been left today as relics too scattered by later changes to be assigned a social meaning any longer.

Do these examples of variation seem familiar to you? What kind of individual-level variation have you noticed between friends and family?