Columbine. Aurora. Newtown. The nation needs answers, and all we get is more death – and more questions.

The most complex question, and by far the most heavily politicized, is why. Why does the United States have a gun-related murder rate 19.5 times higher than that of similarly high-income countries around the world? Why are mass shootings so devastatingly common here? What makes us so perversely special?

Conventional liberals have a ready-made answer: uniquely lax gun laws and the frustrating permanence of the Second Amendment. Conventional conservatives have no similar go-to response; gun rights advocates instead point to causes as diverse as mental illness, the influence of violent video games, a decline in religious belief and the gradual erosion of America’s bedrock Christian morality.

Yet the evidence indicates that these common explanations for America’s high homicide rate are unsatisfactory on their own. Stronger gun laws, for instance, do not always correlate with less gun crime, or vice-versa. Among OECD countries, Mexico, with its near-total ban on private firearm ownership, has a firearm homicide rate three times as high as America’s. Tiny Switzerland, meanwhile, with its strong tradition of militia service, has 420,000 assault rifles stored at private homes and gun ownership rates second only to the U.S. among rich countries – yet the small Alpine nation recorded only 40 gun-related homicides in 2010. America averaged 10,987 per year from 2007 through 2009. The city of Chicago alone recorded twelve murders in the first week of 2012.

Most damningly, our homicide rates are 6.9 times higher than the rich-country average even when all types of murder – not just homicides by gun – are included. If people wanted to kill each other with equal ferocity in other countries, and easier access to guns was the only differentiating factor, we would expect overall murder rates to be much more similar, even if the widespread ownership of guns made them the murder weapon of choice in the U.S.

The mental illness explanation suffers from similar problems, as do the video game and religion narratives. There is no reliable evidence to suggest that the United States has more mentally ill people per capita than other rich countries – though as my colleague Emily Cohodes suggests, we have a long way to go in treating mental illness adequately. Largely secular Europe has murder rates far lower than the heavily religious U.S. And there is actually a negative correlation between video game spending per capita and gun violence; game-crazy Japan, Germany, and South Korea have per-capita murder rates near zero.

I’m no sociologist, but I think there’s something else going on here – something difficult to quantify, and something the media has largely ignored. My guess is that America’s high levels of violence stem at least in part from the slow disappearance of community, broadly defined; communities that give individual lives meaning and bind men together in the social fabric that defines us.

“Man is by nature a social animal,” remarked Aristotle in his Politics; “an individual who is unsocial naturally… is either beneath our notice or more than human.” Sartre, ever the optimist, groaned that “hell is other people” – but history has given him the lie. Human beings, buffeted by the tides of suffering and despair, have always sought solace in their fellow men.

In uniquely diverse America, a land explicitly grounded in difference rather than homogeneity, voluntary association has traditionally slaked man’s thirst for social meaning. Alexis de Tocqueville famously called us “a nation of joiners” as early as 1835, observing that American civil society constituted itself around voluntary institutions like the church, the political party, the reading group and the theater.

But as Harvard sociologist Robert D. Putnam argues in his seminal and troubling work Bowling Alone, participation in collective social ventures, from bowling clubs to voting booths to labor unions to churches to the Boy Scouts, has declined sharply since the 1960s. Putnam laments, with formidable statistical evidence, the slow individualization and atomization of American life. Our connections to each other are fraying, slowly being replaced by the formless void of television and the Internet.

Here could be the missing piece of the sociological puzzle surrounding guns and violence. Japan, Switzerland, Korea – all largely homogeneous societies, whose populations look similar, share basic cultural assumptions, in which each individual naturally recognizes something of himself in his fellow citizen. Belonging to the larger whole is an easy task.

The U.S. is different. It takes more work to appreciate the basic humanity of people who look, talk, eat and entertain themselves differently than you do. Uniquely high levels of income inequality make life qualitatively different for rich and poor, separating social classes into isolated spheres of existence. Voluntary associations and institutions have traditionally helped establish unifying connections across such boundaries, erasing alienating differences and forging ties of common humanity.

With the disappearance of such connections comes dislocation and violence. Philosopher Hannah Arendt has noted that mass killings require the systematic dehumanization of the victim; it is hard to kill someone, after all, with whom one feels a shared sense of being.

It is unsurprising, then, that so many mass murderers kill immediately following a serious withdrawal from society. James Holmes, the Aurora theater shooter, quit his neuroscience graduate program at the University of Colorado in June. He murdered twelve people in July. Even before dropping out, Holmes lacked meaningful connections to the other students in his program. In the words of one fellow student: “He always seemed to be off in his own world, which did not involve other people, as far as I could tell.”

George Hennard, who shot 50 people in Killeen, Texas on the sixteenth of October 1991, was unemployed, and those who knew him described him as “angry and withdrawn.” On Sept. 27, 2012, Andrew Engeldinger shot five people to death in Minneapolis. He had just lost his job. Adam Lanza, the Newtown shooter, was described as a “loner” and “antisocial.” He had craved a sense of belonging and hoped to join the U.S. military. His mother, Nancy Lanza, “squashed” that dream, reminding him that he “didn’t like to be touched.” After dropping out from classes at university in 2009 – the same year his father left the house – Lanza withdrew even further into himself, finally shooting his mother and 26 other people this December.

Enjoying the solitary life does not mean that a murderous rampage is imminent. Nor does it tell the whole story: access to guns, deficiencies in the mental health system and drug and gang-related violence are all part of the picture too.

But if we want to explain this particularly nasty iteration of American Exceptionalism, it would be wise to consider the possibility that death in our communities may flow in part from the death of community itself.

Contact Miles at [email protected].