Illinois researchers found Reddit Answers favors formal, popular comments

Search Engine Journal reports on 17 September that researchers at the University of Illinois Urbana-Champaign have audited Reddit Answers, the generative search product built on top of Reddit content. The paper, "The Wisdom of the Loudest: A Large-Scale Audit of Generative Search on Reddit", was posted to arXiv on 13 September by Agam Goyal, Wang Claire and Eshwar Chandrasekharan, and is a preprint that has not yet been peer-reviewed.

The setup

The team submitted 10,000 questions to Reddit Answers, three times each roughly five hours apart, across 20 advice and support subreddits: ten large ones such as r/personalfinance and ten smaller ones such as r/UKJobs. That produced 30,000 answers, drawn from 14.68 million comments. The abstract says the goal was to see "which community voices survive retrieval and synthesis".

The three numbers a working GEO team should know

Reddit Answers heavily favours highly upvoted comments. Search Engine Journal reports, drawing from the paper, that the median selected comment was at the 91st percentile for score within its thread, and that 92% of the direct replies used in answers came from highly upvoted comments.

Formal, directive language was more likely to be picked, experiential language less so. Search Engine Journal cites the paper's odds ratios: formal language had 1.488 to one odds of selection, a 49% higher chance, while experiential voice had 0.789 to one odds against.

First-person singular language was reduced further during the summary step. Search Engine Journal reports that first-person share fell from 3.3% in the comments Reddit Answers quoted to 0.06% in the final synthesised answer. So the retrieval step already favours other comments over experiential voice, and the summary step then removes even more of what remains.

What the authors say about the mechanism

The abstract states that differences between the three repeated runs were "driven primarily by retrieval", so run-to-run variance comes from which comments Reddit Answers retrieves in the first place. The authors also say answers "routinely combine evidence across communities" rather than staying inside the community the question is asked in. The paper labels itself observational rather than causal, and does not claim a mechanism, only the pattern.

The consequence for a team optimising for Reddit answers

Reddit is now one of the most-cited sources across AI answer products, so what Reddit Answers itself does is close to a guide for how a brand or contributor gets into an AI-cited paragraph on someone else's product. Casual first-person accounts that read as authentic on Reddit itself are always disadvantaged once retrieval and synthesis process them. A contributor whose value is a real story, and a brand relying on organic community advocacy, both need to accept that the version of that story that reaches a summary loses the personal voice. Practically, a comment that leads with a clear, formal claim and earns upvotes on the top-level reply is the kind that gets picked, and comments deep inside a long thread are not.

Source

Reporting: Search Engine Journal, by Matt G. Southern. Primary source: The Wisdom of the Loudest: A Large-Scale Audit of Generative Search on Reddit, by Goyal, Claire and Chandrasekharan, arXiv preprint, 13 September 2026.