A new study published in Nature has found that X’s algorithm—the hidden system or “recipe” that governs which posts appear in your feed and in which order—shifts users’ political opinions in a more conservative direction.
Led by Germain Gauthier from Bocconi University in Italy, it is a rare, real-world randomized experimental study on a major social media platform. And it builds on a growing body of research that shows how these platforms can shape people’s political attitudes.
Two different algorithms
The researchers randomly assigned 4,965 active US-based X users to one of two groups.
The first group used X’s default “For You” feed. This features an algorithm that selects and ranks posts it thinks users will be more likely to engage with, including posts from accounts that they don’t necessarily follow.
The second group used a chronological feed. This only shows posts from accounts users follow, displayed in the order they were posted. The experiment ran for seven weeks during 2023.
Users who switched from the chronological feed to the “For You” feed were 4.7 percentage points more likely to prioritize policy issues favored by US Republicans (for example, crime, inflation and immigration). They were also more likely to view the criminal investigation into US President Donald Trump as unacceptable.
They also shifted in a more pro-Russia direction in regards to the war in Ukraine. For example, these users became 7.4 percentage points less likely to view Ukrainian President Volodymyr Zelenskyy positively, and scored slightly higher on a pro-Russian attitude index overall.
The researchers also examined how the algorithm produced these effects.
They found evidence that the algorithm increased the share of right-leaning content by 2.9 percentage points overall (and 2.5 points among political posts), compared with the chronological feed.
It also significantly demoted the share of posts from traditional news organizations‘ accounts while promoting or boosting posts from political activists.
One of the most concerning findings of the study is the longer-term effects of X’s algorithmic feed. The study showed the algorithm nudged users towards following more right-leaning accounts, and that the new following patterns endured even after switching back to the chronological feed.
In other words, turning the algorithm off didn’t simply “reset” what people see. It had a longer-lasting impact beyond its day-to-day effects.
One piece of a much bigger picture
This new study supports findings of similar studies.
For example, a study in 2022, before Elon Musk had bought Twitter and rebranded it as X, found the platform’s algorithmic systems amplified content from the mainstream political right more than the left in six out of the seven countries.
An experimental study from 2025 re-ranked X feeds to reduce exposure to content that expresses antidemocratic attitudes and partisan animosity. They found this shifted feelings towards their political opponents by more than two points on a 0–100 “feeling thermometer.” This is a shift the authors argued would have normally taken about three years to occur organically in the general population.
My own research offers another piece of evidence to this picture of algorithmic bias on X. Along with my colleague Mark Andrejevic, I analyzed engagement data (such as likes and reposts) from prominent political accounts during the final stages of the 2024 US election.
Our findings unearthed a sudden and unusual spike in engagement with Musk’s account after his endorsement of Trump on July 13—the day of the assassination attempt on Trump. Views on Musk’s posts surged by 138%, retweets by 238%, and likes by 186%. This far outstripped increases on other accounts.
After July 13, right-leaning accounts on X gained significantly greater visibility than progressive ones. The “playing field” for attention and engagement on the platform was tilted thereafter towards right-leaning accounts—a trend that continued for the remainder of the time period we analyzed in that study.
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Publication details
Germain Gauthier et al, The political effects of X’s feed algorithm, Nature (2026). DOI: 10.1038/s41586-026-10098-2
Journal information: Nature
Provided by The Conversation
Source: A few weeks of X’s algorithm can make you more right-wing—and it doesn’t wear off quickly
Robin Edgar
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