Poli‑SHIFT is a dataset and evaluation framework for testing whether signals about the user's political stance systematically move the political stance an LLM expresses.
Poli‑SHIFT holds the underlying policy question fixed and varies one interaction signal at a time. Pick a treatment, then pick a variant, to see the typical direction a model's stance moves (averaged across all seven models).
Stance is scored on a 5-point scale, where higher means more pro-side. “Pro-side” and “anti-side” are the two ends of each issue, such as supporting or opposing military aid to Ukraine.
Every prompt starts from the same political question, adds one interaction signal, and is answered in one of two formats.
Both contested terminology and premise framing move the same model's stance in a consistent direction, for every model. Premise framing produces the larger average shift, and terminology effects are largest under multiple choice.
Pro-side vs. anti-side wording, by model. Dot = mean; whisker = 95% CI.
Mean pro-side minus anti-side stance, in scale points, with 95% confidence intervals.
| Model | MCQ effect (95% CI) | Open-text effect (95% CI) |
|---|
Pro-side vs. anti-side premise, by model. Dot = mean; whisker = 95% CI.
Mean pro-side minus anti-side stance, in scale points, with 95% confidence intervals.
| Model | MCQ effect (95% CI) | Open-text effect (95% CI) |
|---|
The results above are pooled across all seven models. Pick a model to see its own contested-terminology and premise-framing results, in both MCQ and open-text formats, broken down by topic.
Not every topic was collected in every country. The country comparison uses the six topics marked in all three columns.
| Topic | AU | UK | US |
|---|---|---|---|
| Climate Change Policy | ✓ | ✓ | ✓ |
| Immigration & Asylum Policy | ✓ | ✓ | ✓ |
| LGBT+ Rights | ✓ | ✓ | ✓ |
| Healthcare & Public Services | ✓ | ✓ | ✓ |
| Israel-Palestine War | ✓ | ✓ | ✓ |
| Russia-Ukraine War | ✓ | ✓ | ✓ |
| Abortion Rights & Access | ✓ | — | ✓ |
| Brexit & EU Relations | — | ✓ | — |
| Gun Control | — | — | ✓ |
| Indigenous Rights | ✓ | — | — |
Agreement between each pair of raters: number of ratings compared (N), correlation (r), share of exact matches, share within one point, and share landing on the same side of the neutral midpoint.
| Comparison | N | r | Exact | Within 1 | Side agreement |
|---|
Percentage of repeated prompts where independent runs land on opposite sides of the neutral midpoint.
| Model | MCQ · terms | MCQ · premises | OT · terms | OT · premises |
|---|
Partial η² is the share of otherwise unexplained variance that stated ideology accounts for. Coefficients are shifts in scale points relative to an ideologically neutral biography.
| Model | Ideology partial η² | Conservative coef. (95% CI) | Liberal coef. (95% CI) |
|---|
Large language models (LLMs) are increasingly used to answer questions about politically contentious issues, yet evaluations typically treat a model's stance as a relatively stable property. Real users, however, communicate political signals through their terminology, assumptions, and personal context. We investigate whether such signals produce ideological mimicry: systematic shifts in the political stance expressed by an LLM toward the position conveyed by the interaction. We build the Poli-SHIFT dataset and evaluation framework and assess seven open-weight LLMs across ten contentious political topics in the United States, United Kingdom, and Australia, systematically manipulating contested terminology, politically valenced premises, and user information, and eliciting responses in both multiple-choice and open-text formats. Across models, we find robust evidence that prompt framing shapes the political stance of LLM outputs — and that stated political ideology systematically shifts responses toward the user's own position.