Single-Spouse Marriage Systems: the elite male problem

While most human marriages have been one husband, one wife, most human societies have permitted multiple-spouse marriages. Most commonly, they permitted a man to have more than one wife.

Since fathering a child takes rather less inherent biological effort than mothering one, it is hardly surprising that multiple wives (polygyny) is the most common deviation from single-spouse marriage.

In societies where women make substantial contributions to subsistence — almost invariably, hoe-farming societies — rates of polygyny can get very high. For the cost of adding extra wives is much less than in societies where males dominate subsistence activity: typically plough-farming and pastoralist societies.

Foraging societies tend to have low levels of polygyny, as subsistence contributions are relatively even (the subsistence contribution of women is more constant, that of men more nutrient dense) and entirely labour driven. There are no productive assets, beyond weapons and other hand-held tools.

The landscape management and foraging complexity of Aboriginal societies in Australia generated distinctive patterns of gerontocratic polygyny. Old men married young women, young men married their widows and, in their old age, married young women. It kept fertility down and fostered the transfer of complex foraging knowledge across the generations. They also developed some extraordinarily complex marriage-and-kin systems as part of complex landscape management, as that preserved a rolling network of kin connections.

If women control the main productive asset, and there is no other basis for elite male status, then there is no elite male problem. If that is not the case, then if a society is going to have compulsory single-spouse marriage systems, it is the elite males who have to be convinced. There seems to be two general reasons for the elite males to accept single-spouse marriage.

First, there are very strong pressures for social cohesion. If there is a need to have maximum internal cohesiveness against outside groups — specifically, if there is a need to include low-status males — then a single-spouse system minimises internal sexual competition and maximises the breadth of stakes in the success of the group. The fewer elite males there are, the lower the cohesion pressures need to be for such an arrangement to emerge.

This is the pattern that seems to explain the emergence of single-spouse systems in the classical Mediterranean and in groups such as the early Christians and the Alevis. In the case of classical Greece and Rome, access to slaves further reduced the cost of single-spouse marriage to elite males.

The second reason for single-spouse marriage being accepted by elite males is if the education cost of raising a child, particularly a son, to elite status is sufficiently high. Multiple-wife systems mean less investment by the father in individual children. If such an investment is at a premium, then a single wife is a better option.

This is the pattern you see in the Indian caste system and in the modern world. Brahmins could theoretically have multiple wives, but very rarely did, as the training investment in raising a Brahmin son was so high. Indeed, this very high training cost seems likely to be the reason why the jati system developed — to ensure the daughters of Brahmin, who understood the needs of raising a Brahmin son, were available to marry Brahmin grooms.

Single-spouse systems did not develop as territorial or population expansion devices. On the contrary, polygyny is a much better territorial expansion device because it creates a shortage of wives. Polygyny creates a shortage of wives as a woman who gets married leaves the marriage market, but her husband does not. So low-status men end up excluded from the marriage market. The classic response to this problem is “those people over there have women, take theirs”.

Islam sanctified this pattern, with the Quran explicitly endorsing sexual access to “those your right hand possesses” (Ma malakat aymanukum: i.e. women acquired by the sword). Sanctified sexual predation helped drive the territorial expansion of Islam for a thousand years. From its rise in C7th Arabia to the turning back of Islamic expansion into Europe after the Battle of Vienna, 12 September 1683. (And yes, that is apparently why 11 September was chosen in 2001.)

The Norse (Viking) raids also seemed to have been significantly fuelled by polygyny and died away as the Norse lands Christianised.

If external expansion is fuelled by low-status men seeking women that the local marriage market does not provide them, then elite males have no reason to accept a single-spouse system. Which comes back to; if one wants to explain why a single-spouse system is being accepted, then one has to explain why elite males have accepted the system, as they are giving up the benefits of multiple wives.

These musings are part of the intellectual scaffolding for a book to be published by Connor Court looking at the social dynamics of marriage. As they are somewhat a work in progress, they may be subject to ongoing fiddling.