We’re Living in a Split-Screen America

The evolution from broadcast news to personalized feeds has fractured how we see the world, but progress is possible.

“And that’s the way it is.” At least, that’s the way it was. When Walter Cronkite closed his nightly broadcasts with those words, America was a foreign country. At the height of broadcast news, Americans had differences of opinion but agreed on a basic set of facts about what was going on in the country and the world. Anchors like Cronkite, voted in 1972 by Democrats and Republicans alike as the most trusted man in America, aimed to be impartial and to win bipartisan credibility. But as partisan cable news and talk radio came to prominence in the 1990s, basic agreement on the facts began to erode. And with the rise of social media, it splintered entirely.

Platforms like Facebook, YouTube, TikTok, and Twitter personalize content to maximize engagement (time spent on an app, posts liked and shared), showing you what you want to see. That reinforces users’ existing beliefs and limits exposure to opposing views. Strikingly, a Meta-commissioned study of 208 million users during the 2020 U.S. election cycle showed that liberals and conservatives on Facebook encountered almost entirely non-overlapping news sources. Once a social media user spends time looking at political content on one of these platforms, he or she is fed more and more of the same. Far from the broadcasts of the mid-century, modern news is delivered via increasingly bespoke “narrowcast.”

This political siloing is not trivial. Americans now inhabit split-screen realities. In one 2023 Gallup poll, 90 percent of Republicans believed crime was rising, while 60 percent of Democrats believed it was falling. On climate change, a 2021 survey showed a 56-point partisan gap in beliefs about whether humans have a serious impact on the climate system (compared to a 16-point gap in 2001). In 2024, 44 percent of Democrats rated the national economy as “excellent or good,” compared to only 13 percent of Republicans, despite the same underlying economic conditions. The gap wasn’t driven by personal finances, but by partisan interpretations of identical economic indicators. These are not differences of opinion; they are incommensurable beliefs about the state of the world.

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But platforms don’t just feed us headlines that align with our politics. They also bait our strongest emotions. In 2017, Facebook began weighting “angry” reactions five times more heavily than “likes” when floating posts to the top of our feeds. That same year, a study found that each additional moral-emotional word in a tweet (think “shameful,” “detestable”, “evil”) significantly increased the likelihood of it being shared and reshared.

This platform design calls up ancient instincts. Humans evolved to detect threats to the coalition, to signal our group loyalty, and to rally allies against rivals. A tweet calling someone “abhorrent” isn’t just an opinion; it’s a tribal call to action. And because these platforms so reliably elicit our ire and impel us to spread it to others, they’ve become outrage engines.

They create sealed chambers that echo our anger, where contrary evidence is unlikely to penetrate. Carl Sagan now sounds prescient when he warned in 1995 of a future where Americans, embedded in an information economy, would become “unable to distinguish between what feels good and what’s true,” leaving society vulnerable to illusion and manipulation.

And the consequences of the outrage engines don’t stop at our borders. In 2016, Russian operatives used fake personas on Facebook and Twitter to spread inflammatory memes targeting both liberals and conservatives. They didn’t need to hack anything. They simply exploited an information ecosystem already optimized for spreading partisan outrage.

What can be done? There is no single fix, but meaningful improvements are possible.

In a randomized study, older adults who received just one hour of digital literacy training from MediaWise improved their ability to tell false headlines from real ones by 21 percentage points. When Twitter added a prompt asking users if they wanted to read an article before retweeting it, people were 40 percent more likely to click through to the article before sharing it impulsively.

Choice helps too. In one study, switching users from a feed that had been personalized by the algorithm to one that showed posts in chronological order measurably increased their exposure to content across the political aisle. While it may not be a silver bullet, giving users the ability to choose their feed structure, including which algorithm to use, allows for opportunities to be exposed to contrary opinions and to peer outside the echo chamber.

But deeper change is cultural. A compelling case has been made that human reasoning evolved not to uncover objective truth, but to persuade others, to justify our own ideas, and to win arguments. That is why the habits of sound reasoning must be cultivated through norms that prize truth over tribal loyalty, deliberation over impulsivity, and the ability to make the best case for opposing views in order to oppose them on their merits.

This isn’t a call for censorship or government control of the news, nor is it a plea to go back to three-network broadcasting. The democratization of media has brought real benefits, including broader participation in public discourse and greater scrutiny of powerful institutions. But it has also made public life more combustible and has manufactured disagreements about factual questions. In a competition for attention, platforms are designed to maximize time spent on them. That means elevating content that provokes strong emotional responses, especially outrage, and targeting it toward the users most likely to react. The more incendiary the content, the more likely it is to hold us captivated.

What we are witnessing is not a failure of the market, but a particularly efficient version of it, albeit one that optimizes for attention, not accuracy. Personalized feeds, algorithmic curation, and viral content are giving people more of what they want. And yet, many Americans say they are dissatisfied with the result. In a 2023 Pew survey, 86 percent of U.S. adults said they believe Democrats and Republicans are more focused on fighting each other than solving real problems, and respondents across party lines cited political polarization as the biggest problem with the political system.

While online outrage bubbles may not qualify as a market failure in the technical sense, they are clearly a civic problem worth confronting. An information ecosystem optimized for attention rather than accuracy will reliably amplify division and distrust, even while giving users more of what they like to see and share. The incentives are working as designed, but the outcome is a fragmented public unable to agree on the real state of the world. If democracy depends on a shared understanding of basic facts of the matter, then reckoning with these tradeoffs is well worth our much-demanded attention.

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Author: Dylan Tweed, an Institute Fellow and PhD Candidate in Cognition, Brain, and Behavior at Harvard University.

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