Ψ-Bench evaluates personalized persuasion through conversations between two models: the tested LLM attempts to influence a client instantiated by DeepSeek-v3.2 from a hidden profile. It contains three tasks. Viewpoint Debate uses the first 500 of 2,131 Change My View threads; Psychological Consultation uses 90 CounselBench questions; Everyday Request contains 100 GPT-4o-generated requests. Each dialogue lasts three rounds. Another DeepSeek-v3.2, which sees the profile and full conversation, assigns 1-to-9 scores for quality, personalization, and effect: opinion change, psychological improvement, or request acceptance. Debate profiles are written by DeepSeek from topic frequencies and LIWC attributes associated with the Reddit user. In the other tasks, PersonaMem-v2 profiles are sampled and refined to fit the query. These are not verified demographics or psychometric assessments. The prompts require every field to be filled, instruct the model to select one plausible value when evidence is absent, and prohibit uncertainty language; the so-called ground-truth profile therefore contains guesses about age, gender, origin, occupation, religion, family, politics, and personality. The client also receives a shared engineered resistance: firm views in Debate, severe distress and resistance to change in Consultation, or busyness and independence in Request. Ten models are tested. Quality usually exceeds 7/9, while mean Effect ranges from 4.05 for Qwen3-8B to 5.79 for GPT-5.1. GPT-5.1 leads Debate (6.12), Request (5.88), and the average; Qwen3-80B-A3B leads Consultation (6.10). Quality and Personalize correlate .752 and .772 with Effect, although all three scores come from the same judge over the same synthetic dialogues. On human CMV dialogues, judge Effect reaches .960 AUC for detecting delta; on CounselBench, Quality reaches .780 against the expert label, but no patient follow-up exists to validate Treatment Effect. When reconstructing the final human CMV response, the profiled client reaches .669 AUC versus .605 without a profile: this is a modest gain and does not compare generated language with that person's actual response. The human study asks five participants for profiles and creates 50 paired conversations totaling 150 turns. Judge means are similar for human and simulated clients, but correlations are only .45-.50; per-response fidelity and blind human preference are not measured. Oracle gives the persuader the same synthetic profile already conditioning the client and visible to the judge. The paper then reports +41.19% Personalize and +18.24% Effect. This demonstrates that rubric-aligned shared information helps inside the loop, not an 18.24% increase in persuasion of real people. The profile analyzer predicts a JSON profile from dialogue. Qwen3-4B-RL, trained with GRPO and BGE-M3 similarity to synthetic profiles, reports 55% versus 51.30% for DeepSeek-v3.2. However, the released CMV split is not user-independent: 102 identifiers occur in both train and test, and 149 of the 500 test queries belong to a persona already present in train. The analyzer sometimes exceeding Oracle with only about 50% profile similarity also suggests it may produce text useful for steering the persuader or satisfying the judge rather than recovering real facts. The official repository publishes queries, profiles, prompts, scripts, data releases, and a PyPI wheel, but not generations, item scores, the human study, LlamaGuard decisions, GRPO training, or Qwen3-4B-RL weights. It also has failures that prevent treating it as a reference implementation: the recommended CLI does not pass --task, so counsel and request execute with CMV prompts and metrics; generation mutates every profile in memory and appends resistance again each turn; the source build fails because a nonexistent fig package is declared; vllm is imported but undeclared; and requirements contains an invalid character. There are no tests or CI. A further unaddressed privacy risk is that 1,636 inferred profiles, including age, gender, religion, and politics, are published under Reddit usernames alongside 2,131 direct thread URLs. The defensible contribution is a public dataset and experimental structure for comparing models inside a controlled personalized simulation. It does not establish realistic users, true profiling, clinical effectiveness, human behavior change, persuasive safety, or end-to-end reproducibility.
Research question
To what extent can different LLMs influence simulated clients conditioned by profiles through dialogue, does improving access to or inference of those profiles increase the scored effect, and does this simulation serve as an approximation to human users?