You ARE seeing it in practice. This particular social experiment has been going on for last 40 years, as in most of Western world marriage became less of a necessity, and people are (theoretically) free to sleep with whoever they want and as many as they want.
Which is probably due to the widespread availability of effective birth control. Women could put off having children in pursuit of an education and a career. They could also take on many more partners.
And guess what -- what Cain describes is not happening. Or mostly not happening. Extremely successful men who openly bed multiple women exist, but they are very few.
Well, polygamy would make it more acceptable. Of course, polygamy would have to achieve a certain amount of acceptability in order for it to become legal and push more acceptance. Really rich men would be IDIOTS for marrying multiple wives. These guys already hate splitting a fortune two ways.
It also requires women desperate for marriage. Through most of history it was literally a life-and-death necessity for a woman to "get a man of her own". Nowadays, much less so.
I failed to account for this one. Good point.
Monogamy is so deeply ingrained in our culture I think that most women will still prefer it to being a rich dude's third wife.
Well, ideally a woman wants to get a high-status man who has options yet commits to her and only her
for life. But what's the likelihood these men still having sex outside marriage, especially when she hits, 35/40? I think just a slight change in the rules, and a small number of women opting for group marriage can have ripple effects.
Anyway, the same time I read Wright's book I was taking a woman's studies class. One of the readings mentioned how the introduction of horses to Native American tribes altered marriage dynamics: since the best hunters could now kill many more animals, the author said they needed more wives to polish the hides or some ****, and polygamy rose. I don't think that's the whole story: some Tiger Woods equivalent is going to ATTRACT more women in part because he can provide for them.
In America today more women are graduating from college than men and the wage gap is shrinking. Among young women they are even surpassing males as wage earners in some cases. You would think that this would make women change their preferred mate somewhat, from rich guy to good husband and father guy.
What about ingrained genes? My initial post seemed to imply too much calculation going on in a woman's head; people do not typically run cost-benefit analysis, especially when it comes to love. Women are attracted to men of means. The traditional reason for having a man around was to ward off attackers and protect the children. According to Jared Diamond, the reason why humans do not have a breeding season is because men would abandon partner and brood. I think historically, women do not select men on the basis of being a "great dad," or even today. Marriage is primarily about raising children, but child-rearing skills are not a proportionally high consideration. Older women who see their desirability in the sexual market declining will marry provider-type nice guys. The ******** father the children and the step-fathers pour resources into raising them.
Historically females probably wanted macho guys who could kick some ass. They still notoriously select for height, many reporting they just feel "more protected" in the arms of a larger man. This is kind of stupid considering we have guns, but stone age brains in modern skulls and all of that.
Everyone talks about finding a good father figures, finding "the mother of my children." I'm going to call B.S. on women who self-report that stay at home dads are sexy. Men who wear baby carriers and hold their wives purses are emasculating themselves, reducing sexiness in the eyes of women. That only works if you have enough man-cred (only Nixon can go to China). Men tend to be more transparent.
Finally, women tend to be more hypergamous than men. A woman with a masters degree who makes fifty thousand dollars a year will want a man the same age or older with at least the same level of education and income. He should also be taller than she is.
And 5 or 6 (or more) women running about the place with PMT 
. Dude!
.
