Polygyny is a significant structural factor governing divorce in countries where this is permitted. Little-to-no analysis has been completed to explicitly explain the link between marital instability and polygyny which leads to divorce. The frequency of divorce rises in polygynous marriages compared to monogamous relationships. Within polygynous unions, differences in conjugal stability are found to occur by wife order. There are 3 main mechanisms through which polygyny affects divorce: economic restraint, sexual satisfaction, and childlessness. Many women escape economic restraint through divorcing their spouses when they are allowed to initiate a divorce.
Causes.
In the western world as a whole, two thirds of divorces are initiated by women. In the United Sates, 69% of divorces are initiated by women and this may be due to higher sensitivity to relationship difficulties. An annual study in the UK by management consultants Grant Thornton, estimates the main proximal causes of divorce based on surveys of matrimonial lawyers.
The main causes in 2004 were:
Adultery; Extramarital sex; Infidelity – 27%.
Domestic violence – 17%.
Midlife crisis – 13%.
Addictions, for example alcoholism and gambling – 6%.
Workaholism – 6%.
Other factors – 31%.
According to this survey, husbands engaged in extramarital affairs in 75% of cases, and wives in 25%. In cases of family strain, wives' families were the primary source of strain in 78%, compared to 22% of husbands' families. Emotional and physical abuse were more evenly split, with wives affected in 60% and husbands in 40% of cases. In 70% of workaholism-related divorces it was husbands who were the cause, and in 30%, wives. The 2004 survey found that 93% of divorce cases were petitioned by wives, very few of which were contested. 53% of divorces were marriages that had lasted 10 to 15 years, with 40% ending after 5 to 10 years. The first 5 years are relatively divorce-free, and if a marriage survives more than 20 years it is unlikely to end in divorce.
Social scientists study the causes of divorce in terms of underlying factors that may motivate divorce. One of these factors is the age at which a person gets married; delaying marriage may provide more opportunity or experience in choosing a compatible partner. Wage, income, and sex ratios are other such underlying factors that have been included in analyses by sociologists and economists.
The elevation of divorce rates among couples who cohabited before marriage is called the "cohabitation effect". Evidence suggests that although this correlation is partly due to two forms of selection (a) that persons whose moral or religious codes permit cohabitation are also more likely to consider divorce permitted by morality or religion and (b) that marriage based on low levels of commitment is more common among couples who cohabit than among couples who do not, such that the mean and median levels of commitment at the start of marriage are lower among cohabiting than among non-cohabiting couples), the cohabitation experience itself exerts at least some independent effect on the subsequent marital union.
In 2010, a study by Jay Teachman published in Journal of Marriage and Family found that women who have cohabited or had premarital sex with men other than their husbands have an increased risk of divorce and that this effect is strongest for women who have cohabited with multiple men before marriage. To Teachman, the fact that the elevated risk of divorce is only experienced when the premarital partner(s) is someone other than the husband indicates that premarital sex and cohabitation are now a normal part of the courtship process in the United States. This study only considers data on women in the 1995 National Survey of Family Growth in the United States. Divorce is sometimes caused by one of the partners finding the other unattractive.
