"What marriage had in common was that it really was not about the relationship between the man and the woman," said Stephanie Coontz, the author of "Marriage, a History: How Love Conquered Marriage," (Penguin Books, 2006).
"It was a way of getting in-laws, of making alliances and expanding the family labor force." But as family plots of land gave way to market economies and Kings ceded power to democracies, the notion of marriage transformed.
Once marriage was not legally based on complementary, gender-based roles, gay marriage seemed like a logical next step.
"One of the reasons for the stunningly rapid increase in acceptance of same sex marriage is because heterosexuals have completely changed their notion of what marriage is between a man and a woman," Coontz said.
In fact, in Victorian England, many held that women didn't have strong sexual urges at all, Coontz said. Market economics Around the world, family-arranged alliances have gradually given way to love matches, and a transition from an agricultural to a market economy plays a big role in that transition, Coontz said.
"There was a protracted battle between the Catholic Church and the old nobility and kings who wanted to say ' I can take a second wife,'" Coontz said.For instance, in the United States, marital rape was legal in many states until the 1970s, and women often could not open credit cards in their own names, Coontz said.Women were entitled to support from their husbands, but didn't have the right to decide on the distribution of community property.And if a wife was injured or killed, a man could sue the responsible party for depriving him of "services around the home," whereas women didn't have the same option, Coontz said. Partnership of equals By about 50 years ago, the notion that men and women had identical obligations within marriage began to take root.Instead of being about unique, gender-based roles, most partners conceived of their unions in terms of flexible divisions of labor, companionship, and mutual sexual attraction. Gay marriage gains ground Changes in straight marriage paved the way for gay marriage.