Cousin marriage in the Middle East works differently than does cousin marriage in South India.
Dr Alice Evans has a wonderful blog post, essay really, on why the situation of women in South India is generally better than that of women in North India. The piece is comprehensively researched and very well reasoned.
I do however, have one quibble. It is with Dr Evans using cousin marriage in the Middle East to argue that cousin marriage in South India is not likely to be a significant explanatory factor in the comparatively better position of women in South India. The trouble with this is that cousin marriage in the Middle East is marriage within the lineage group, so therefore is parallel marriage.
Given that kin groups in the Middle East are patrilineal (male line), women thereby marry male relatives within their own patri-lineage. Such marriages do not add to their kin connections but they also mean that women are not married into a completely different lineage. They are therefore not separated off from their natal kin.
Such parallel marriages mean the women are not further disadvantaged in the way that marrying into a completely different patri-lineage can entail, which is why women in the Middle East are likely to favour cousin marriages. A favouring that might well matter more than expected in such patriarchal societies, as women have long been the marriage intermediaries in those societies. These being societies with a long history of sexual segregation.
In South India, cousin marriages are cross-cousin marriages. That is, given that the kin groups are also patrilineal, they are marriages into a different patri-lineage with which there are already maternal kin connections.
Such cross-cousin marriages mean that, while women are married into a different patri-lineage, their connections with their natal lineages are reinforced. Indeed, it is a sign that those female kin connections are valued.
So women in South India acquire kin connections with such marriage but their natal connections retain significance. This is a stronger intermediary role than parallel-cousin marriage generally provides and gives them two sets of operative and valued kin connections to operate within and through. This puts them in a rather better position than women in North India.
In North India, marriages are often arranged at least two villages away. So women are more thoroughly separated from their natal kin group and more completely dependant on their husband’s kin group and kin connections. It is a way of making the patri-lineage more coherent, likely as an adaptation to North India having a much greater history of invasion. It is, however, done so very much at the expense of women.
Marrying out, marrying in
Parallel (i.e. within kin group) marriages are actually quite unusual in human societies. Normally, kin groups enforce strong taboos against marrying within the kin group. This is typically enforced through strong ritual boundaries requiring differentiation between the spouse with the ritually significant ancestors and the spouse who is an import to the kin group.
Such “ancestor worship” (though it is probably better understood as ancestor ritualisation) is incompatible with monotheism. Adoption of monotheism generally eliminates those ritual boundaries, leading to reasons to marry within the kin group becoming more socially dominant.
Though not so much in the case of Christianity, which is antipathetic to kin groups and has a history of expansively anathematising marriage between relatives, though nowadays much less than it used to. A very good book on this is Michael Mitterauer, Why Europe?: the Medieval Origins of Its Special Path.
In the case of patri-lineages, marrying within the kin group means that daughters will be breeding warriors for the lineage, not for a different lineage. It also means that property (especially animal herds) remain within the kin group (as any bride price or bride wealth stays within the kin group) and that the genetic and kin-connection cohesion of the kin group will be increased.
South India is not an area where monotheism is strong. So it retains the more normal pattern of kin groups marrying out (of the kin group). In the case of patrilineal groups, that means kin groups trade daughters. (Matrilineal kin groups trade sons.)
In South India, it has been quite common for a man with an older sister to marry one of her daughters. Or else, the daughter of one of his mother’s siblings (i.e. a cousin). With the kin-connection consequences noted above. At the very least, they likely operate to facilitate or magnify the causal agents Dr Evans identifies.
So, while I agree cross-cousin marriage is not enough on its own to explain the better position of women in South India compared to North India, I would still argue that it helps to improve the situation of women in South India. Since parallel-cousin marriage in the Middle East is not a good analogy to cross-cousin marriage in South India, cousin marriage in the Middle East is not a good counter-argument against the significance of cousin marriage in South India for the relatively higher status of women compared to North India.