@inproceedings{liu-etal-2026-persona,
title = "Persona-{CAPS}: Controllable and Auditable {LLM} Personality via Retrieval over Situation{--}Behavior Contingencies",
author = "Liu, Guanghao and
An, Guangzhou and
Xu, Yang and
Chen, YU",
editor = "Lee, Hung-Yi and
Dev, Sunipa and
Li, Jessy and
Elliott, Desmond",
booktitle = "Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.emnlp-main.1495/",
pages = "34153--34184",
ISBN = "979-8-89176-459-0",
abstract = "LLM persona control divides between trait-prompt strings and model-specific activation-steering vectors; neither offers a per-response trace from output to persona contents. We introduce Persona-CAPS, a retrieval-based persona framework grounded in the Cognitive-Affective Personality System (Mischel and Shoda, 1995): a persona is a corpus of if (situation) then (behavior) contingencies mined from public Experience Sampling Method data, retrieved per-situation, each fired atom logged to its source observation. An audit-loop study quantifies three structural properties paragraph baselines lack: retrieval exposes corpus-level corruption that paragraph dilution masks (P{\texttwosuperior}-sanity passes 0/9 on MiniMax low-Openness under identical polarity injection); atom-level repair uses {\textasciitilde}1/3 the paragraph-baseline character footprint at comparable fix success (byte-identical on 13/13 paired GPT-4o cross-vendor conditions); and two audit modes (universal-recall sweep, sparse-edit triage) support deployment-time governance. Across six backbones, CAPS beats Simple-Prompt on all three backbones of PersonalityBench (Deng et al., 2025) (mean +0.69/10), delivers monotonic 1-D continuous control via mixture weights {\ensuremath{\pi}} on all 15 (vendor {\texttimes} Big-Five) Mini-IPIP cells, and matches the strongest paragraph baseline (P{\texttwosuperior}) on the non-all-low 5-D profiles ({\textsection}4.6; backbone-level direction-match {\ensuremath{\geq}} 0.93). Cross-family judge replication (r = +0.951) and a two-rater human pack triangulate the headline. Code, corpus, and logs are released."
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<abstract>LLM persona control divides between trait-prompt strings and model-specific activation-steering vectors; neither offers a per-response trace from output to persona contents. We introduce Persona-CAPS, a retrieval-based persona framework grounded in the Cognitive-Affective Personality System (Mischel and Shoda, 1995): a persona is a corpus of if (situation) then (behavior) contingencies mined from public Experience Sampling Method data, retrieved per-situation, each fired atom logged to its source observation. An audit-loop study quantifies three structural properties paragraph baselines lack: retrieval exposes corpus-level corruption that paragraph dilution masks (P²-sanity passes 0/9 on MiniMax low-Openness under identical polarity injection); atom-level repair uses ~1/3 the paragraph-baseline character footprint at comparable fix success (byte-identical on 13/13 paired GPT-4o cross-vendor conditions); and two audit modes (universal-recall sweep, sparse-edit triage) support deployment-time governance. Across six backbones, CAPS beats Simple-Prompt on all three backbones of PersonalityBench (Deng et al., 2025) (mean +0.69/10), delivers monotonic 1-D continuous control via mixture weights \ensuremathπ on all 15 (vendor × Big-Five) Mini-IPIP cells, and matches the strongest paragraph baseline (P²) on the non-all-low 5-D profiles (§4.6; backbone-level direction-match \ensuremath\geq 0.93). Cross-family judge replication (r = +0.951) and a two-rater human pack triangulate the headline. Code, corpus, and logs are released.</abstract>
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%0 Conference Proceedings
%T Persona-CAPS: Controllable and Auditable LLM Personality via Retrieval over Situation–Behavior Contingencies
%A Liu, Guanghao
%A An, Guangzhou
%A Xu, Yang
%A Chen, Y. U.
%Y Lee, Hung-Yi
%Y Dev, Sunipa
%Y Li, Jessy
%Y Elliott, Desmond
%S Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-459-0
%F liu-etal-2026-persona
%X LLM persona control divides between trait-prompt strings and model-specific activation-steering vectors; neither offers a per-response trace from output to persona contents. We introduce Persona-CAPS, a retrieval-based persona framework grounded in the Cognitive-Affective Personality System (Mischel and Shoda, 1995): a persona is a corpus of if (situation) then (behavior) contingencies mined from public Experience Sampling Method data, retrieved per-situation, each fired atom logged to its source observation. An audit-loop study quantifies three structural properties paragraph baselines lack: retrieval exposes corpus-level corruption that paragraph dilution masks (P²-sanity passes 0/9 on MiniMax low-Openness under identical polarity injection); atom-level repair uses ~1/3 the paragraph-baseline character footprint at comparable fix success (byte-identical on 13/13 paired GPT-4o cross-vendor conditions); and two audit modes (universal-recall sweep, sparse-edit triage) support deployment-time governance. Across six backbones, CAPS beats Simple-Prompt on all three backbones of PersonalityBench (Deng et al., 2025) (mean +0.69/10), delivers monotonic 1-D continuous control via mixture weights \ensuremathπ on all 15 (vendor × Big-Five) Mini-IPIP cells, and matches the strongest paragraph baseline (P²) on the non-all-low 5-D profiles (§4.6; backbone-level direction-match \ensuremath\geq 0.93). Cross-family judge replication (r = +0.951) and a two-rater human pack triangulate the headline. Code, corpus, and logs are released.
%U https://aclanthology.org/2026.emnlp-main.1495/
%P 34153-34184
Markdown (Informal)
[Persona-CAPS: Controllable and Auditable LLM Personality via Retrieval over Situation–Behavior Contingencies](https://aclanthology.org/2026.emnlp-main.1495/) (Liu et al., EMNLP 2026)
ACL