Matrilineal descent systems, of which there are several well-known examples in south-western and north-eastern India, have their own distinctive characteristics. Empirically you never find matrilineal systems that are an exact inverse of the patrilineal-patriarchal model which we have already described, which is fairly well approximated by the patrilineal descent systems of north and south (but especially north) India. The reason is quite simple; whatever the descent system, that is, matrilineal, patrilineal or indeed bilateral, authority is usually exercised by males, only in extremely simple societies. One comes across a fair degree of mutual inter-dependence between males and females. Also, though rights, in property might be determined by the principles of matrilineal descent. For instance, passing from mother to daughter or from mother's brother to sister's son rather than from father to son as in patrilineal societies, major property is usually controlled (if not actually owned) by males.