King's College London

Researchers have discovered the key to more constructive political argument online lies in the approach.

New research, published in Science Advances, shows how we approach political debate online has powerful ripple effects - shaping not only the civility and tone but also the quality and substance of responses.

In their study, researchers used innovative AI large language models to engage participants on political issues that mattered most to them. More than 3,000 people in the UK and US were asked to write a social media post on their favoured issued before being shown a counterargument generated by AI that varied in tone, justification type, political affiliation, and willingness to compromise.

It found that maintaining a respectful tone and showing a willingness to compromise can double the likelihood of receiving a high-quality response - defined as providing a reasoned justification while avoiding toxic language or partisan political attacks.

The findings were revealed in a new study co-authored by King’s College London academic Anne Rasmussen, with Tobias Heide-Jorgensen and Gregory Eady (University of Copenhagen).

Study results showed that evidence-based, respectful, and compromise-seeking counterarguments produced by the AI substantially improved discourse quality, doubling the likelihood of receiving high-quality replies.

In addition, suggesting compromise not only increased openness to compromise but had the spillover effect of reducing disrespectful replies. These approaches also made participants more open to alternative viewpoints. Notably, these positive effects held even in toxic environments or when interacting with those of a different political standpoint, showing the robustness of constructive approaches.

Study co-author, Professor Anne Rasmussen said: “We show how using large language models allows us to systematically test and demonstrate that evidence-based justifications, respectful tone, and signals of willingness to compromise produce exceptionally large improvements in the quality of online political discussion.

“Our findings also reveal important spillover effects: suggesting compromise reduces incivility, while providing justifications increases the likelihood of suggesting a compromise, illustrating how different elements of dialogue shape one another.”

However, despite improving debate quality, these approaches were no better at changing opinions than low-quality debate. Prof Rasmussen, from the Department of Political Economy at King’s, added: “Changing minds on deeply held, salient issues is hard. But fostering reasoned, respectful, and open discourse – even without persuasion – is a valuable democratic outcome in itself.”