According to the Pew Research Center, less than half (46%) of U.S. kids younger than 18 years of age are living in a home with two married parents in their first marriage.

In the United States, single parents are heralded as superheroes. Searching the term "single parent superheroes" online demonstrates this is a very mainstream idea. Mainstream media -- the news, TV shows, and movies -- act as though children raised by single parents are just as resilient or better than children who are raised in two-parent households.

Yet that's not the case. On Father's Day in 2008, President Obama said:

"There’s a hole in your heart if you don’t have a male figure in the home that can guide you and lead you and set a good example for you. "We know the statistics — that children who grow up without a father are five times more likely to live in poverty and commit crime, nine times more likely to drop out of schools and 20 times more likely to end up in prison. They are more likely to have behavioral problems, or run away from home, or become teenage parents themselves. And the foundations of our community are weaker because of it.”

These stats have long been known. In 1997, The Journal of Research in Crime and Delinquency reported that the most reliable indicator of violent crime in a community is the proportion of fatherless families. This is especially true for families with adolescent boys, the most crime-prone cohort. It goes on to state that:

"Children from single-parent families are more prone than children from two-parent families to use drugs, be gang members, be expelled from school, be committed to reform institutions, and become juvenile murderers."

Think about that for a moment.

Single parenting is the most reliable indicator of whether or not a child will grow up to be a murderer.

Now I'm not indicting single parents...I've been one for over six years. I'm saying that children need to be raised by both parents and extended family to thrive, not just by one parent alone.

The National Institutes of Health's U.S. National Library of Medicine reports in pertinent part: "Psychiatric disorders were found to occur with higher frequency in children of single parent families, especially those lacking a father," and "was most frequent in the children who had experienced the divorce of their parents."

In 2006, The Guardian reported:

"Boys whose parents had split up had the highest rate of childhood mental illness. In contrast, only 8% of boys living with married parents suffered from mental disorders."

Politifact even reports that solid research has shown that growing up in a single-family household, even if other factors are controlled, has a negative effect.

The fact that most of the mass shooters in the United States were products of broken homes and single parents shouldn't be surprising. These young men raised in single-parent homes were more likely to be violent criminals with mental health issues -- something most mass shooters have in common.

This is not to say that lax gun regulations in the United States or the mental health crisis shouldn't be addressed -- they should. They're definitely contributing factors, but they're symptoms only. If we focus on them alone, we risk ignoring the problem of children being raised in broken homes.

Make no mistake, with over half of American children raised in single-parent households, this is a growing epidemic that appears to be getting worse. I have no short-term solution to this problem. I do know that moving forward, if both parents treated each other as permanent family, like they do their children -- rather than as spouses who are disposable -- American families would be stronger and society would be better for it.

Who knows? Maybe these shootings will cease.