The study, published in November 2025, involved 1,256 participants on X during the 2024 U.S. presidential campaign. Researchers from the University of Washington, Stanford University and Northeastern University built a browser-based tool that reranked posts in real time without removing content and without requiring the platform’s cooperation, according to the paper.
Participants whose feeds were adjusted to reduce posts expressing antidemocratic attitudes and partisan animosity showed a measured improvement in feelings toward the opposing party. The researchers said the shift, while modest, typically takes about three years to occur naturally.
“This finding raises a question the study did not set out to answer: where does the hostility come from in the first place?” Carlos Cantero, a Chilean academic at the International University of La Rioja in Spain and author of “Digital Society: Reason and Emotion,” wrote in an opinion piece for United Press International. “Algorithms did not invent tribal hatred. They amplified it. The fire was already burning.”
Cantero argued that the human tendency toward us-versus-them thinking is an evolutionary inheritance, and that digital platforms have converted that ancient impulse into a technical system in which outrage generates engagement and revenue. He cited the French philosopher Éric Sadin’s observation that “the reptilian brain has become a source of profit in network society.”
The commentary drew on psychological theories from Sigmund Freud, Carl Jung and social psychologist Jonathan Haidt to describe how digital triggers activate primal responses. Canetro wrote that “intuition moves before reason” and that when groups feel threatened, “rationality often shuts down.”
The study’s finding that a single algorithmic adjustment can measurably alter political attitudes within days has implications for who controls feed-ranking systems, the commentary said. “Authority over that ranking is a civic matter, not simply a product decision,” Canetro wrote, adding that the question is particularly urgent in Latin America, where institutional trust is already fragile.
But Canetro cautioned that the deeper problem predates digital platforms. “The beast that stalks the human soul is not technological,” he wrote. “The response to it cannot be either. The first task is not to perfect the algorithm, but to recover the moral capacity to see an adversary as fully human.”