This spring, MIT economist David Autor and coauthor Melanie Wasserman suggested a reason for this: the growing number of fatherless homes. Boys and young men weren’t behaving rationally, they suggested, because their family situations had left them without the necessary attitudes and skills to adapt to changing social and economic conditions. Anyone interested in the plight of poor and working-class men — and, more broadly, mobility and the American dream — should hope this research, and the considerable biological and psychological evidence behind it, become part of the public debate.

[…]Autor and Wasserman cite a large study by University of Chicago sociologists Marianne Bertrand and Jessica Pan, which shows that, by fifth grade, fatherless boys were more disruptive than peers from two-parent families, and by eighth grade, they had a substantially greater likelihood of getting suspended. And justice experts have long known that juvenile facilities and adult jails overflow with sons from broken families.

This part is interesting because the data contradicts the liberal narrative:

Liberals often assume that these kinds of social problems result from our stingy support system for single mothers and their children. Provide more maternity leave, quality daycare and healthcare, goes the thinking, and a lot of the disadvantages of single-parent homes would vanish. But the link between criminality and fatherlessness holds even in countries with lavish social welfare systems. A 2006 Finnish study of 2,700 boys, for instance, concluded that living in a non-intact family at age 8 predicted a variety of criminal offenses.

But maybe fathers can be substituted for with “male role models”, like liberals say? NOPE:

Professors Cynthia Harper and Sara McLanahan found that among boys they studied, the ones without fathers were more likely to be incarcerated, but they also found that those who lived with stepfathers were at even higher risk of incarceration than the single-mom cohort.

So fathers really do matter to boys, and they can’t be replaced with money or stepfathers or live-in boyfriends. Now I asked some liberal women about children needing mothers and fathers and they replied that adults should be allowed to do anything they want, and then let children adjust. I think in those conversations we really need to be armed with evidence and work through the evidence with people who want to assert that they are an exception to the evidence because they are “good mothers” or “good fathers” and don’t need a spouse to raise a child. It seems to me that if you are denying a child one parent, then you are not a good parent yourself.

We really need to hammer into the heads of grown-ups that these moral boundaries are in place for a reason – to protect children. A lot of people who support arrangements that deprive children of their biological mother or their biological father might like to think that they are good parents and care about children, but they don’t. And it’s our job to hold them accountable for harming children. Ask them: are you for no-fault divorce? are you for gay marriage? are you for single-mother welfare? And so on. If the answers come back yes, then hold them accountable for harming children. We have to be brave in order to protect children.