Affective polarization—emotional hostility toward political opponents—represents a particularly dangerous form of division. Unlike disagreement about policies, which can fuel productive democratic debate, affective polarization involves viewing those with different political views as enemies rather than fellow citizens, potentially undermining democracy’s foundational premise of peaceful coexistence despite disagreement.
The research measured affective polarization specifically, using feeling thermometers to capture how warm or cold participants felt toward political opponents rather than simply measuring policy disagreements. Over 1,000 X users received modified feeds during the 2024 presidential election, with those exposed to more divisive content reporting significantly colder feelings toward the other party.
This emotional dimension distinguishes contemporary polarization from earlier eras of political division. Americans have always disagreed about politics, but they historically maintained basic respect and recognition of shared citizenship. Affective polarization erodes these foundations, replacing respectful disagreement with visceral hostility that makes compromise and cooperation nearly impossible.
The speed at which algorithms can increase affective polarization proves particularly concerning. One week of subtly altered feeds produced emotional shifts matching three years of natural development. This acceleration suggests that platform choices may be one of the primary drivers of contemporary affective polarization, potentially more important than underlying policy disagreements or demographic changes.
Reversing affective polarization will require concerted efforts. The research showed that down-ranking divisive content can reduce hostility, suggesting one technical intervention. But broader cultural work may be necessary to rebuild norms of mutual respect and shared citizenship that affective polarization has eroded. Whether such rebuilding is possible in environments where algorithms continue amplifying division remains an urgent open question.