A U.S.-backed Syrian Democratic Forces (SDF) fighter stands atop a building used as a temporary base near the last land still held by Islamic State militants in Baghouz, Syria, last month. Beheadings by the militants in 2014 are the subject of a new study exploring why people choose to view ghastly images, and what toll they exact. (Felipe Dana/AP)

Roxane Cohen Silver began trying to understand how graphic images pollute the human psyche in the terror-struck days after the 9/11 attacks, when sights and sounds of the twin towers crumbling flooded newspapers, television and radio.

The latest work by the professor of psychological science at the University of California at Irvine arrives in the midst of a reckoning with another terrorist attack. The massacre on Friday of 50 people at two mosques in Christchurch, New Zealand, occurred halfway around the globe from Ground Zero, but on a whole other planet of opportunities to view extremist violence.

In 2001, the images of billowing smoke got their oxygen almost exclusively from legacy media. In 2019, the rat-a-tat of gunfire issuing from semiautomatic weapons — and footage of the bloodshed inflicted by the weaponry — became available live on Facebook and other social media platforms.

The grisly events in New Zealand, which reignited debate about the ethics of viewing terrorist propaganda and the responsibilities of technology companies to curtail its circulation, occurred soon after Silver’s newest paper appeared in the American Psychologist, the flagship journal of the American Psychological Association. Her results, published late last month, hold clues about what sort of people are drawn to these images of destruction, as well as the psychological toll the gruesome material may take.

The study, “Who Watches an ISIS Beheading — and Why,” examines engagement with videos depicting the decapitation of journalists James Foley and Steven Sotloff. The videos, each several minutes in length, appeared on the Internet about three weeks apart in 2014.

They shocked the world, enlisting modern methods to achieve barbaric ends. But the paper is the first to quantify how many people actually watched this graphic content, who these people were and what their motivations were for doing so.

In a survey of more than 3,000 U.S. residents that began in 2013 and lasted for three years, Silver and her colleagues at UCI found that 20 percent had watched at least part of a beheading video, while 5 percent said they had watched an entire one.

Survey participants were more likely to say they had watched the beheading videos if they also said they were male, Christian or unemployed. Those who reported watching television more often were also more likely to view the videos. So, too, was fear of future terrorism associated with greater likelihood of watching. Prior mental health conditions were not significant factors, but a lifetime exposure to violence was.

Age mattered only slightly. Yet, contrary to the widespread belief that young people are more prone to perusing the dark corners of the Internet, Silver noted, the tendency to watch the videos actually increased with age.

Most likely to engage with graphic content, Silver has found, are those who are already afraid of what they think they might encounter. The content has its desired effect, the paper concludes, increasing distress and fear of future negative events.

When we subject ourselves to images, sounds and videos created and distributed by terrorists, said Silver, who is the paper’s senior author, “We’re doing terrorists’ job for them."

Terrorists have long understood their own psychological effect, staging public executions to instill fear. Such elaborate planning isn’t required in the modern age, when social media has made every act potentially public.

Silver, for her part, has not watched the videos. Nor has she viewed the gunman’s footage from Christchurch, or read the 74-page manifesto that has been linked to him. “And if you have not, I would discourage you from seeking them out,” she said in an interview with The Washington Post.

Building on her work on the 9/11 attacks and the 2013 Boston Marathon bombing, the paper contributes to research demonstrating the deleterious effect of graphic content on the mental health of those who consume it. The new paper reached the notable conclusion, said Sarah Redmond, the first author and a PhD candidate in psychological science at UCI, that “individuals who view these images may be at risk for the same psychological and physical distress symptoms usually seen in those directly exposed to trauma.”

The conclusions speak to individual motivations for viewing the ghastly online content, as well as its personals costs.

“It’s not merely the responsibility of social media organizations but also the responsibility of the consumer to be aware of the potential negative consequences of exposure to these kinds of images,” Silver said.

But the results are inseparable from the public debate over the burden borne by digital platforms, which have been criticized for acting too slowly to remove hateful material. On Friday, Reddit shut down a blow-by-blow discussion of the mosque shootings unfolding on a subreddit called “Watch People Die,” an online forum hosting videos of people suffering hideous deaths.

The power of these sites is enhanced by the fierce devotion of their users. A report released this week by members of the British Parliament said addiction to social media should be classified as a disease.

“It’s such a different picture,” Silver observed, recalling how network television largely abstained after 9/11 from showing victims falling to their deaths, and how some newspapers sought to erase the famous “Falling Man” photo after first running it in the days after the attacks. “Teams of editors, perhaps, came to the conclusion to exercise restraint. It seems that nobody is making those decisions in 2019, when people carry smartphones in their hands that can very rapidly upload images and videos.”

Underscoring the difficulty of regulating a space as vast as social media, Facebook on Monday said a video of the Christchurch gunman’s rampage had been viewed about 4,000 times before it was taken down. Not one of the roughly 200 users who tuned in to the live broadcast reported the material, according to the social networking giant.

As for why they watched in the first place, the study by the psychological scientists suggests possible reasons. While the data showed that fear of future terrorism was a significant factor, respondents — in accounting for their own motivations — said they were mainly on an information-gathering mission. The paper further argues that allusions to the graphic nature of the videos in the media, as well as still images published in print and online, may increase the curiosity of viewers.

By contrast, emotional factors were prominent in the decision to stop a video before its completion.

The researchers were not able to conclude that the material was so harmful as to impair a viewer’s capacity to function or complete day-to-day tasks. Nevertheless, Silver cheered the decision to shut out the images.

“I can say unequivocally that there is no psychological benefit to exposure to graphic images of horror,” she said.