Organizations: Faculty of Computer and Information Science, University of Haifa, Israel · School of Therapy, Counseling and Human Development, University of Haifa, Israel · The PhD Program of Hermeneutics and Culture, Interdisciplinary Studies Unit, Bar-Ilan University, Israel · Department of Psychology, Bar-Ilan University, Israel
Existing approaches to persona simulation with Large Language Models (LLMs) mostly rely on shallow character descriptions that fail to sustain coherent character behavior across extended interactions. We introduce Deep Persona, a psychologically grounded, three-layered architecture that organizes personas into hierarchical levels of observable expression, latent beliefs, and core motivational drives, for constructing highly convincing role-playing agents. Governed by the principles of scripted determinism and bounded agency, the architecture restricts the model to a reactive engine guided by a structured internal script. We further propose a reference-free evaluation framework that benchmarks dialogue naturalness against empirical human distributions using established psychological clinical instruments and adversarial stress-tests. Empirical evaluation reveals that while LLMs achieve high pragmatic fluency, they exhibit systematic limitations in emotional expression and joint attention. In addition, we present a case study of two Deep Personas and evaluate them using the proposed framework, demonstrating that structured personas can produce interactions that more closely align with human conversational behavior.
Figures & tables
Figure 1: An illustration of the differences between a flat persona and the Deep Persona framework.
Information revealed only after trust or progression
Middle Layer
Table 1: Mapping interview dimensions to prompt specification components in the Deep Persona methodology.
Dataset
Spragmatics
Sjoint-attention
Semotion
DailyDialog
0.9400
0.3521
0.1152
CC (H-H)
0.9680
0.8854
1.4264
Table 2: Human baseline scores for the proposed dialogue evaluation metrics for the DailyDialog dataset and the human to human interactions from the CounselChat (human-human) (CC).
Dataset
Spragmatics
Sjoint-attention
Semotion
RP Boss
0.8881
0.8390
0.2068
RP Classmate
0.8923
0.7808
0.2934
RP Vanilla
0.8918
0.8221
0.2646
ABC-Eval
0.8931
0.4594
0.1108
CC (H-LLM)
0.9676
0.9344
2.2054
Sarah
0.9402
0.5202
0.4918
Table 3: Scoring profiles showing the average values for the datasets of Role-Play (RP), ABC-Eval, and CounselChat (human-LLM) (CC). At the bottom are the scores of the deep personas Sarah and Evelyn.
DailyDialog
CounselChat (H-H)
Combined Baseline
Evaluated Dataset
DNS
# Dialogues
DNS
# Turns
DNS
# Dialogues
Role-Play Boss
0.6618
26/28
0.0600
0/28
0.6899
26/28
Role-Play Classmate
0.6665
26/28
0.0529
0/28
0.7467
27/28
Role-Play Vanilla
0.6705
28/29
0.0645
0/29
0.7266
28/29
ABC-Eval
0.8181
505/528
0.0633
0/528
0.7929
504/528
CounselChat (H-LLM)
0.0479
124/3507
0.7940
3118/3507
0.5254
2107/3507
Table 4: DNS Scores for the datasets of Role-Play, ABC-Eval, CounselChat (human-LLM), and for the deep personas Sarah and Evelyn. The # Dialogues indicates the number of dialogues where the agent was statistically indistinguishable from a human ( p>0.05 ). Scores are calculated with respect to human baselines from the DailyDialog dataset, the CounselChat (human-human) dataset, and a combined baseline pooling both human-human datasets.
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
Dataset
Metric
μ
σ
Pragmatic Fluidity & Echolalia
RP Boss
Sˉoverlap
0.1772
0.0404
Sˉself
0.1522
0.0335
Erate
0.0045
0.0236
Spragmatics
0.8881
0.0222
RP Classmate
Sˉoverlap
0.1582
0.0371
Appendix
Table 5: Full table of scores for the datasets of Role-Play Tao et al. (2024) (RR), ABC-Eval Finch et al. (2023) , and CounselChat (human-LLM) Bird et al. (2024) (CC). For Spragmatics : α=β=γ=0.33 , and for Semotion : α=0.7 and β=0.3 .