Samul Said/Reuters

The past several months have been scarred by international crisis and turmoil, from strife in Gaza to the downing of Flight MH17 and the gruesome murders of the American journalists James Foley and Steven Sotloff. News is so grim that The Washington Post recently published an accounting of what it called "the hideous carnage wreaked" between June and early September: an untold number killed in Syria (where the civil war's death toll may now exceed 200,000, though the UN has stopped counting); more than 5,500 killed in Iraq; over 1,500 killed in Ukraine; and nearly 2,000 killed by Ebola in West Africa. An estimated 550,000 to 1.4 million people could be infected with Ebola by January in a worst-case scenario.

When it comes to the humans behind these statistics, however, not all casualties are covered equally. Researchers have found that the U.S. media gives more sustained and personalized attention to some deaths than to others. What informs the decision about whether a victim of violence or disaster gets an obituary, or is simply subsumed into a bigger number?

"The international news calculus is always the same," explains Jack Lule, chair of journalism and communication at Lehigh University, who has studied how The New York Times editorial page responded to the attacks of September 11, 2001. "First, is there a local person in the disaster or on board a plane that has crashed? If so, the local victims get intense focus that simplifies [the] international crisis or conflict for readers. … Overall, there is this concept of 'worthy' and 'unworthy' victims in the media."  

Before the murders of James Foley and Steven Sotloff, ISIS had slaughtered thousands of people. But it was the public and brutal killing of "local" journalists—and the coverage these acts received in the U.S. by fellow reporters—that seems to have turned U.S. public opinion and the Obama administration dramatically in favor of the current military campaign against ISIS in Syria and Iraq.  

This kind of focus on local victims was clearly visible in the aftermath of the 9/11 attacks, when The New York Times published informal but detailed obituaries for more than 2,500 of those killed. The amount of coverage devoted to individual lives was extremely unusual for a mass-casualty event with a death toll close to 3,000. "This was certainly a traumatic event for the country, but for The Times, it was really also a local reporting event," Lule explains. "It's harder to say whether they would have done something like this if the event had happened in San Francisco or Los Angeles."

But what happens when disaster, natural or otherwise, strikes overseas, as it did repeatedly this summer? How does the U.S. media prioritize the rest of the world? William C. Adams, professor of public policy and public administration at George Washington University, attempted to answer this question in a 1986 study of news coverage of 35 natural disasters between January 1972 and June 1985 that each took at least 300 lives, including cyclones, typhoons, hurricanes, and earthquakes. Tallying the minutes major television networks (NBC, ABC, and CBS) devoted to each, he found that the severity of the disaster did not by itself predict the amount of coverage an incident received—more deaths did not necessarily translate to more airtime. For example, among earthquakes occurring in six countries in 1976, he wrote: "Guatemala experienced one of the worst earthquakes in this century in the Western hemisphere," with the official death toll later put at 4,000. "Yet, proportionate to the number of victims, it received one-third of the coverage given the Italian earthquake" that killed nearly 1,000 people that year.

Adams found that other than the death toll, two factors mattered most in predicting how much coverage an international disaster received on U.S. television: the event's geographic proximity to the U.S., and the number of U.S. tourists who visited the country in which the disaster took place. This latter factor, explains Robert Lichter, director of the Center for Media and Public Affairs at George Mason University, is a measure of a country's "cultural proximity" or interest for American news consumers.

Adams's research dealt with mass-casualty natural disasters; wars and attacks are subject to different calculations in the media. "The possibility that someone might have wanted … to kill people directs greater attention to those who have specifically been targeted," says Christine Muller, an American studies lecturer at Yale University who researches how popular culture generates meaning in the wake of extreme events. According to Mardi Horowitz, a professor of psychiatry at the University of California, San Francisco, many people experience a heightened level of distress when they see other human beings acting as predators.

The New York Times, for example, compiled individual portraits of several of those killed on Malaysia Airlines Flight 17, which was shot down over eastern Ukraine in July with 298 passengers aboard. By contrast, after Malaysia Airlines Flight 370 disappeared in March with 239 passengers onboard for reasons that remain unclear, the paper devoted an article to the victims as a group—which included "artists and corporate salespeople, foreign businesspeople and technology firms"—but did not focus on any specific individual. While Flight 370 vanished mysteriously, Flight 17 appears to have involved a clearer villain: pro-Russian separatists firing a Russian-made missile. And with antagonists comes the natural human inclination to establish and memorialize protagonists.

Then there's the "newsworthiness" of the event—a subjective determination by journalists that is often predicated on factors like the fame or distinction of the victims or the shock factor of the story.

"Yes, an American journalist fits into the model that makes us feel empathy for the victim, but the video of the beheading of an American journalist has a particular novelty and severity that sets it apart," says Lichter. Alternatively, when a plane crashes in the middle of a war zone and investigators are scrambling to collect bodies and personal effects, there's a visceral element of surprise to the story that drives sustained and personalized coverage. While readers may be somewhat familiar with a crash investigation that centers on mechanical errors and inclement weather, the notion that another person or group of people shot down a plane (even by mistake) carries weight.

Tragedies that seem to have a deeper significance also tend to get more attention. A tornado that kills schoolchildren is horribly sad; a young man who guns down kindergarteners holds a mirror to the society in which he lives. "There are exceptions of course, but if we perceive there is something more meaningful, more than an accident or a tornado, there is much more of an urge to memorialize" the victims, says Marita Sturken, a professor of media, culture, and communication at New York University.

Another factor is the presence of children, explains Andrew Silke, a criminology professor at the University of East London. For example, more than 2,000 people died this summer in fighting between Israel and Hamas in Gaza; early in the conflict, however, the death of four Palestinian boys playing on a beach "stood out," in the words of a New York Times report, "because they were inarguably blameless, children who simply wanted to play on their favorite beach." Says Silke: "Children in mass tragedies … usually receive more attention than adults in similar situations." Patrick R. Grzanka, professor of psychology at the University of Tennessee, notes that children can help bridge the psychological space between readers and subjects separated by physical or cultural distance, though race, class, and other social factors may buffer these effects.

In some cases, high death tolls actually numb news consumers to important stories. Psychologists call the phenomenon "collapse of compassion" and have demonstrated that interview subjects report feeling less empathy for the suffering of groups than that of individuals, so that, perversely, sympathy may diminish as death tolls rise. A hypothetical attack that claims 1 victim will likely stoke less fear and receive less press attention than one that claims 11 victims, explains John F. Morrison, a lecturer at the University of East London who researches terrorism. But the media will treat an attack that kills 101 victims similarly to one that kills 111 victims—both are "mass-casualty" events, despite the higher death toll of the second. "Now apply this to conflicts which have thousands of victims," he says.

And all this has very real consequences. When a news outlet decides whose life is worthy of coverage and which deaths are instead part of a larger statistic, it shapes the public's perspective of a given crisis and even, at times, sways government policy. Without personal stories of those lost, it's nearly impossible to comprehend or empathize with a calamity happening a world away. On the other hand, when the media covers every individual killed in a certain disaster, it may be at the expense of another crisis that deserves attention.