A disturbed sex ratio with remarkably lower male ratio seems to be a logical factor that may give rise to Polygamy in a society; usually there are other social and economic factors responsible for this practice. In most of the societies practicing Polygamy it is as means of improving one’s social status and increasing social dominance. Having more than one wife means one’s economic capacity to sustain bigger families. It also implies one’s economic capability of paying bride price again and again while adding to the number of wives. In many societies part from adding to one’s social prestige it is also indicative of heroism. Look at Nagas of India where the number is not added by payment of bride price but by capturing them in raids on the villages of their traditional enemies. In society having military tradition, male population is miserably effected adding to the number of widow.
Polygamy may come out to be as most adaptive (though not necessarily) cultural option. Three types of new relationships appear in a polygynous house-hold the co wives, half siblings and step mother because of which family management requires specific measures such as isolation of co-wives and socialization of children in accordance with the multiplicity of relations. It has some adaptive advantages too. Particularly among advanced farmers, with high rate of infant) mortality, more hands are required to manage the cultivation.
As such a number of wives and more children became an economic asset. Apart form advanced farmers in Africa and Middle East among herding people and primitive farmers-with backward technology, hard physical labour any frequent threat of violence, polygyny serves to protect their interests. But among the hunting and gathering people where children are a liability and only widows may be accepted as another wife Polygamy can never be a prefered form of marriage. So also in modern civilized and industrialized societies—with greater mobility it has no adaptive advantage to provide. In primitive societies and medieval feudal societies, kings and feudal lords kept and maintained more wives as mark of prestige and status symbol. Despite male predominance, status of women in these societies is not uniform ally low. Rather, in some societies women welcome the addition of a co-wife as it ease their work load.
The system permits a high degree of sexual freedom to women. Concubinage is an institution whereby a man may have extramarital relations with number of women who while not enjoying the status of being a wife but their children can have taken care of by the genitor. In societies where this type of relations is permitted, there are cultural means to legalize the children born of such sex relations and their economic provisions.
The women have no rights and are entirely at the pleasure and mercy of their masters. In medieval China, where monogamy was the strict rule, the kings and feudal lords kept number of such women for sex who were economically provided and their children were treated at par with the children of their wife but their women did not enjoy the rights and privileges available to the married women. The concubines as they are called always remained at the mercy and pleasure of their masters. As such, concubinage is no polygyny. Polyandry—the plurality of husbands, occurs primarily in Tibet, Nepal and India. It is also reported among the Eskimos of Siberia.
It is an adaptation to a shortage of females as among Todas and Pahari Hindus of Himalayan foot hills. Among the Todas the traditional custom of female infanticide lead to the shortage of females. Among the Tibetians where this institution has the oldest roots— it is the shortage of land which lead to the fraternal Polyandry where several brothers together have a common wife. In India it is reported among the Khasas of Jaunsar Bhabar in UP the Todas of Nilgiri Hills in South India and at some time among the Nayars of Malabar.
Like Tibetians, Todas and Khasas practice fraternal polyandry while among Nayars it used to be of non-fraternal type where by various husbands of a woman used to be unrelated to each other and their co-wife used to live with each one of them intermittently. In a polyandrous society since the question of biological fatherhood always remains enigmatic there are cultural ways to establish social fatherhood. Among the Khasas and in Tibet, the privilege of social fatherhood is enjoyed by the elder brother who actually marries the women and his other brothers became husbands of the common wife by custom. Among the Todas, there is some amount of liberalism in this respect where social fatherhood was acquired in turn by performing a simple bow ceremony at the time of the pregnancy of the woman. Occasionally, non fraternal polyandry is also reported among the Todas. Polyandry restricts the number of children that are born and also the fragmentation of meagre cultivable land as the brothers, as common husbands own it jointly. This has played an important adaptive role among the Khasas and Tibetians. However, among the Khasas the developmental activity in the region by the state Govt, providing irrigational facilities has changed the economic prospects because of the people taking to cash crops.
As a consequence, polyandry among the Khasas has been replaced by monogamy. It is only in the interiors of the vast area where the impact of development has not reached; one may find a family or two still being polyandrous.