One example given is that it leads to feral males - men who with no wives or children to domesticate them who run wild and turn to crime.
So why bring this up?
These are boom times for memoirs about growing up in, marrying into or escaping from polygamous families. Sister wives appear as minor celebrities in the pages of People, piggybacking on their popular reality TV show. And oh yes, we have a presidential candidate whose great-grandfather was an actual bona fide polygamist.Slate has written about the TV shows before so I suspect that the real reason for bringing it up is the unnamed presidential candidate. This is a chance to remind us how strange and different Romney's background is. Is this a valid topic or a hit piece?
One argument in favor of it being a hit piece is the great-grandfather reference. You have four great-grandfathers and most people never met their great-grandparents. Did this particular great-grandfather have any influence on the current candidate?
Next, let's consider the studies. Polygamy is only legal in a limited part of the world, mainly Muslim areas. Any studies of legal polygamy are going to be irrelevant to 19th century Mormons or the few polygamous families currently in the US. The part about unmarried men has absolutely nothing to do with the Mormons. They had the opposite problem. They attracted many more women than men and polygamy was a way of providing for the excess female population. Excess men being unable to find women was the least of their problems.
But this is a problem in the Muslim world which is the main place that polygamy is practiced.
This leads to a huge question - the grandfather of Barack Obama was a polygamist. His Kenyan "grandmother" was one of his grandfather's younger wives. What is more, Obama's father was legally a polygamist. He was still legally married to his first Kenyan wife when he married Obama's mother. Why is Romney's great-grandfather a matter of interest but Obama's grandfather is not?
Sounds like a hit piece to me.