Note on Oblique Exchange in a Matrilineal Society in the Comoro Islands

The best known example of oblique marriage, i.e. marriage between an ego and an alter in adjacent genealogical levels, involves the marriage of a man with his ZD, to whom he himself is MB. There are a number of discussions of this phenomenon (Rivière 1969, Lavé 1966, Good 1980; also Parkin 1997: 106-8), but in general it is probably best interpreted as a variant of bilateral cross-cousin marriage in which a man takes his ZD as a wife not for his son but for himself. One property of the model is that, assuming lineage exogamy, such marriages are ruled out where there is matrilineal descent, as ZD and MB would then be in the same matrilineage (e.g. Good 1981). Accordingly the model of such systems is usually constructed in patrilines, even where descent in the society concerned may be cognatic. However, a recent work by Ian Walker on the island of Ngazidja in the Comoro Islands shows how a similar model can be constructed in matrilines (2010: 122, Fig. 3.11). As this has some theoretical interest, I am adding a few notes of my own on it here. Walker calls this arrangement, known as mirande, ‘an explicitly recognized strategy’ of spouse exchange between matrilineages (ibid.: 120), though it is far from being the only marriage strategy on Ngazidja (see ibid.: 116ff.). That is, marriages take place between matrilineages or daho, but normally within the higher-order hinya (matriclan). Some marriages take place within the daho, i.e. to classificatory MZD, especially, it seems, within ruling and other high-status daho, in order to keep the daho ‘pure’ and perhaps also to retain wealth and power within it. Such marriages give rise to some disquiet, though their motives are well understood (Walker ibid.: 117). As for hinya endogamy, this may be linked to the fact that hinya are ranked (Iain Walker, personal communication) and are therefore concerned not to undermine their ranking by entering into unsuitable alliances with other hinya.