A friend of mine came across a news item that she knew I would appreciate. You see, it turns out that 2 really IS better than one. At least when it comes to wives. The study looked at men older than 60 from 140 countries that practice polygamy and found that they lived an average of 12 percent longer than men from 49 monogamous nations, according to a report from the Times of India.
An interesting point, they looked at 140 nations, only 49 of them are monogamous? Our sensitive Judeo-Christian sense of propriety makes us think that monogamy is the norm, but it seems that it isn't. The study chalks up the difference in life span to the polygamous man having a greater reason to live. While that is possible I would suggest that a greater division of labor would also play a big part of the difference. A home requires X amount of work to maintain. X includes income from outside sources as well as upkeep of the homes via chores. Adding an another adult doesn't to the household doesn't mean that the work required is now X+X, rather it is X+Y with Y being only a fraction of Y. Furthermore there are more people to give upkeep meaning that each adult in the house has less to do than before.
The above affect could also apply to income. In modern, western, society the model has the man working a full time job, and often the wife has to hold down at least a part time job just to make ends meet. For simplicities sake, lets then assume that it takes 60 hours of outside income each week to maintain the household. If another wife was added who also worked 20 hours a week, this extra income would push them above merely the economic holding pattern that we see here in the West and is no doubt what others see across the world. Perhaps one of the women is particularly employable (or simply enjoys working) and the other wants to stay at home with the children? These are options available to a polygamous family which would likely reduce the stress placed upon each member, improving their quality of life.