Which linguistic features predict persuasion only after audience composition is held constant?

This explores what happens to the "persuasive language" story once you account for the audience listening to it. The most direct answer in the corpus is unsettling: many linguistic features that look predictive in standard analyses are actually artifacts of *who showed up*, not what was said. When debate corpora are modeled without controlling for the audience, the language appears to carry the persuasion — but Does what readers believe matter more than what debaters say? shows that voters' political and religious ideology outpredicts linguistic features outright, because audience composition is correlated with debate topics. The language effect was riding on a hidden passenger.

The sharper finding for your exact question is in Do linguistic features of persuasion stay the same across audiences?: the set of features that predict persuasion *changes* once ideology is added as a control. Features that ranked as top predictors in naive analyses often reflected audience-text matching — the right readers being drawn to the right arguments — rather than any intrinsic persuasive property of the words. So the honest answer to "which features predict only after holding audience constant" is partly a warning: a large share of published features predict *less*, not more, once you control, and the survivors are different ones. The corpus doesn't hand you a clean list of newly-promoted features so much as it tells you the leaderboard reshuffles.

What *does* survive controls, across adjacent work, tends to be content-independent register rather than topical word choice. Does linguistic conviction explain why LLMs persuade more effectively? isolates expressed conviction — confidence-loading in the phrasing — as a persuasion amplifier that works regardless of whether claims are true or false, which is exactly the kind of feature that wouldn't wash out when you control for audience ideology because it doesn't depend on topic-audience matching. Similarly, Why are presuppositions more persuasive than direct assertions? points to a structural mechanism: presuppositions persuade more than assertions by smuggling claims in as already-accepted background, bypassing scrutiny. These are features tied to *how* something is said, not *what* topic it's about — the kind that should remain predictive after audience composition is held fixed.

There's a useful cross-domain contrast lurking here. Can simple linguistic features detect AI-written arguments? shows that interpretable linguistic features can detect AI-authored arguments with near-perfect accuracy — proof that stylistic signatures are real and measurable. But *detectable* and *persuasive-after-controls* are different bars: a feature can be a reliable fingerprint of who wrote the text while contributing nothing to whether it changed a reader's mind. The audience-control literature is precisely the tool that separates those two — and it's why the field-wide null in the-pooled-effect-of-llm-vs-human-persuasion-is-statistically-null-the matters: when speaker category and audience are properly accounted for, persuasion turns out to be conditional on context, not a property you can read off the surface language alone.

The thing worth taking away: "persuasive language" research has a confound problem, and the audience is the confound. Holding it constant doesn't just refine the answer — it can invert it, demoting topical features that were really audience-matching in disguise and promoting register-level features like conviction and presupposition that work independently of who's listening.