If you missed the first part of this important series, you can find it here:  How to Defend Marriage Reality, Part 1

Two recent books, one by libertarian Charles Murray, the other by progressive Robert Putnam, tell much the same story: upper income Americans are more likely to enjoy a traditional marriage culture where men and women marry, stay married and wait until marriage to have children. For lower-income Americans, in contrast, co-habitation, childbirth without marriage and absentee fathers are quickly becoming the norms rather than the exceptions.

The marriage track involves a virtuous circle. If you graduate from high school and college, get married and then have children, neither you nor your children are likely to live in poverty. And your kids are likely to follow in your footsteps. In contrast, if you don’t graduate from high school or college, hook up and have babies out of wedlock, you’re likely to be poor and to stay poor. And your kids are likely to follow in your footsteps. In short, the poorer among us have suffered disproportionately from the decline in marriage, and the decline in marriage helps keep poorer Americans poor.

That’s why marriage and the family aren’t just a Christian thing. Marriage is a human thing. It may be personal, but it is not private. Like a rock dropped in a pond, assaults on marriage create ripples that work their way across the entire surface of civilization. The difference is that the pond ripples disappear; the cultural repercussions do not.

The collapse of marriage and the epidemic of divorce since the 1960s have given social scientists decades of data to study, and the results are in: marriage is good for us and divorce is not.

Men and women in their first marriages tend to be healthier and happier than their counterparts in every other type of relationship — single, widowed or divorced. They’re also less depressed and anxious, and less likely to abuse drugs and alcohol. “Seventy percent of chronic problem drinkers are divorced or separated, and only 15 percent are married,” note Glenn Stanton and Bill Maier.

Married adults are, on average, more sexually fulfilled. They’re also, on average, better parents, better workers and are less likely to be perpetrators or victims of domestic violence.

Let’s be honest. Most men, left to their own fallen instincts, would be promiscuous. Their sexual energies need to be properly channeled so that they think and act for long-term goals rather than fleeting, short-term pleasure. George Gilder argued in the 1970s and ’80s that the channeling of male sexual activity is one of the most important functions of marriage. It’s crucial for civilization because it helps civilize men. Other scholars have confirmed Gilder’s point, by showing a link between the state of marriage and the historical rise and fall of civilizations.

Social scientists have concluded that married men are less likely to commit crime and more likely to hold down jobs. You don’t need a Ph.D. in sociology to see that unattached single men wandering the streets are more inclined to trouble than the same men attached to wives and children.

Single people can, of course, live fulfilling lives. The Apostle Paul commends the single life as a wonderful gift for those who are called to it (1 Corinthians 7:7-8). I have friends — not just Catholic priests and nuns but evangelical lay men and women — who are called to the single life. It’s easy, perhaps too easy, for us married folks to forget that singleness has its own dignity. And for some vocations, it’s arguably better to be single than to be married.

Those of us called to marriage, however, tend to be much better off if we are married rather than divorced. Marriage scholars Linda Waite and Maggie Gallagher sum up the results of thousands of scientific studies: “A good marriage is both men’s and women’s best bet for living a long and healthy life.”

They’re speaking statistically, of course. Any institution can be distorted and even destroyed by human sin, and stout souls can sometimes overcome even the worst circumstances, including abuse and abandonment. Still, all things being equal, marriage is good for us.

Of course, all this data involves marriage as everyone understood it until week before last: between a man and a woman. If you’ve been reading the paper or the Internet recently, however, you might be thinking: if marriage is such a good thing, why would we want to deprive same-sex attracted men and women of it? Why wouldn’t we want men to be able to marry men and women marry women, if they love each other? What’s the problem?

To answer that, we have to first answer a prior question: What exactly is marriage? That’s the subject of the next part of this series.

Jay Richards is Executive Editor of The Stream. Follow him on Twitter.

If you missed the first part of this important series, you can find it here:  How to Defend Marriage Reality, Part 1