A groundbreaking Yale University study reveals that social media platforms like Twitter amplify moral outrage over time. Users who express outrage receive more likes and shares, with the strongest effects among those in politically moderate networks.
“Social media incentives are changing the tone of our political conversations online,” says William Brady, a postdoctoral researcher in Yale’s Department of Psychology and lead author of the study. He collaborated with Molly Crockett, an associate professor of psychology at Yale.
The Yale researchers analyzed moral outrage expressions on Twitter during real-world controversies and ran controlled experiments to examine how platform algorithms reward popular content, including outraged posts.
“This is the first evidence that over time, some people learn to express more outrage as they are rewarded by the basic design of social media,” Brady explains.
Moral outrage can drive positive change by punishing wrongdoing, fostering cooperation, and sparking reform. Yet it also fuels harassment of minorities, disinformation, and political polarization, the researchers note.
Platforms like Facebook and Twitter claim to offer neutral spaces for discourse. But suspicions persist that they exacerbate outrage—until now, solid evidence was scarce due to challenges in measuring such expressions.
To address this, Brady and Crockett’s team developed machine learning tools to detect moral outrage in tweets. Analyzing 12.7 million tweets from 7,331 users, they confirmed users express more outrage over time when rewarded with likes and retweets.
Controlled experiments further validated that these social rewards increase future outrage expressions.
The findings link to debates on social media’s role in polarization: Extreme political networks show baseline higher outrage, but moderates are most swayed by rewards.
“Our studies show that people with politically moderate friends and followers are more sensitive to social feedback that amplifies their outrage,” Crockett says. “This suggests a mechanism for how moderate groups can radicalize politically over time—social media rewards create feedback loops that exacerbate outrage.”
The study doesn’t judge outrage amplification as inherently good or bad, Crockett emphasizes, but highlights implications for platform leaders and regulators.
“Amplifying moral outrage is a clear consequence of the social media business model, which optimizes for engagement,” she notes. “As outrage drives social and political change, tech companies’ designs can shape collective movements’ outcomes.”
She adds: “Our data shows platforms don’t just reflect society—they create incentives that alter how users react to political events over time.”
