How Personality Traits Shape LLM Risk-Taking Behaviour

John Hartley, Conor Brian Hamill, Dale Seddon, Devesh Batra, Ramin Okhrati, Raad Khraishi


Abstract
Large Language Models (LLMs) are increasingly deployed as autonomous agents for simulation and decision-making, necessitating a deeper understanding of their decision-making behaviour under risk. We investigate the relationship between LLMs’ personality traits and risk-propensity, applying Cumulative Prospect Theory (CPT) and the Big Five personality framework. We compare the behaviour of several LLMs to human baselines. Our findings show that the majority of the models investigated are risk-neutral rational agents, whilst displaying higher Conscientiousness and Agreeableness traits, coupled with lower Neuroticism. Interventions on Big Five traits, particularly Openness, influence the risk-propensity of several LLMs. Advanced models mirror human personality-risk patterns, suggesting that cognitive biases can be surfaced by optimal prompting. However, their distilled variants show no cognitive bias, suggesting limitations to knowledge transfer processes. Notably, Openness emerges as the most influential factor to risk-propensity, aligning with human baselines. In contrast, less advanced models demonstrate inconsistent generalization of the personality-risk relationship. This research advances our understanding of LLM behaviour under risk and highlights the potential and limitations of personality-based interventions in shaping LLM decision-making.
Anthology ID:
2025.findings-acl.1085
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
21068–21092
Language:
URL:
https://preview.aclanthology.org/landing_page/2025.findings-acl.1085/
DOI:
Bibkey:
Cite (ACL):
John Hartley, Conor Brian Hamill, Dale Seddon, Devesh Batra, Ramin Okhrati, and Raad Khraishi. 2025. How Personality Traits Shape LLM Risk-Taking Behaviour. In Findings of the Association for Computational Linguistics: ACL 2025, pages 21068–21092, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
How Personality Traits Shape LLM Risk-Taking Behaviour (Hartley et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/landing_page/2025.findings-acl.1085.pdf