PerSo: Investigating Facets of LLMs' Social Intelligence in Real-World Persuasion Scenarios
Authors: Ali Zamani, Soroush Esfahanian, Erfan Shahabi, Mohammad Taher Pilehvar, Azadeh Shakery, Yadollah Yaghoobzadeh
Organizations: School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran · Cardiff University, United Kingdom · Institute for Research in Fundamental Sciences (IPM), Tehran, Iran · Tehran Institute for Advanced Studies, Khatam University, Tehran, Iran
Understanding the social intelligence of large language models (LLMs) is increasingly important for applications involving human-AI interaction and multi-agent environments. Social intelligence comprises two aspects: cognitive intelligence, the ability to infer others' mental states, and behavioral intelligence, the ability to select appropriate social actions based on these inferences to achieve social goals. Persuasion provides a natural testbed in which both aspects are simultaneously at play, yet prior benchmarks typically evaluate them in isolation using synthetic scenarios. We introduce PerSo, a benchmark that evaluates both aspects on real-world persuasion dialogues from Reddit's ChangeMyView community, using an LLM-in-the-loop pipeline to construct the evaluation tasks, validated through human annotation. Our evaluation of diverse LLMs shows that performance generally scales with model size but varies across dimensions. The strongest LLM slightly surpasses the best observed human performance on the behavioral task, while the best human participant remains ahead on the cognitive task.
Figures & tables
Benchmark
Real Human Data
Cognitive
Cog. Aspects
Cog. Type
Behavioral
FaNToM ( Kim et al., 2023 )
✗
✓
B
R
✗
DYNToM ( Xiao et al., 2025 )
✗
✓
B, E, I, A
R
✗
PersuasiveToM ( Yu et al., 2025 )
✗
✓
B, D, I
R
✗
SocialEval ( Zhou et al., 2025 )
✗
✗
–
–
✓
SOTOPIA ( Zhou et al., 2023 )
✗
✗
–
–
✓
AgentSense ( Mou et al., 2025 )
✗
✗
–
–
✓
Table 1: Comparison of social intelligence benchmarks. B: Belief, D: Desire, E: Emotion, I: Intention/Intent, A: Action. R: mental-state recognition, where the target state is inferred from observed text; F: mental-state forecasting, where the target state is predicted before observing the subsequent utterance that manifests it.
Figure 1: Overview of the PerSo pipeline: data extraction and processing from CMV, multiple-choice question generation for cognitive intelligence, and the behavioral and cognitive intelligence evaluation tasks.
Dataset overview
Threads
200
Date range
Jan 2024–Oct 2025
Label balance (A / B)
100 / 100
Text length (words)
Mean
Median
OP initial post
449
400
Persuader response ( + )
242
182
Table 2: Summary statistics of the PerSo dataset.
Participant
PerSo accuracy (%)
TSIS scores (%)
Behavioral
Cognitive
Social Information Processing
Social Skills
Social Awareness
Belief
Emotion
Intent
A
65.0
85.0
65.0
85.0
79
61
71
B
40.0
50.0
52.5
60.0
54
54
50
C
75.0
75.0
62.5
72.5
50
75
64
Table 3: Participant-level PerSo accuracy and TSIS scores. PerSo results were obtained before gold-label annotation on 20 behavioral instances and 40 cognitive instances per dimension, following the protocol in Section 4.1.2 . TSIS is a self-report measure ( Silvera et al., 2001 ) . Bold indicates the highest value in each score column.
Dimension
A–B
A–C
B–C
Avg. κ
Belief
100.0% 1.000
90.0% 0.866
90.0% 0.866
0.911
Emotion
70.0% 0.601
70.0% 0.602
75.0% 0.667
0.623
Intent
82.5% 0.764
72.5% 0.630
80.0% 0.733
0.709
Table 4: Pairwise agreement (%, first line) and Cohen’s κ (second line) for cognitive answer selection with the final OP reply visible.
Model
Behavioral Intelligence
Cognitive Intelligence
Behavioral
Belief
Emotion
Intent
Gemma-4B
60.5
50.0
20.5
54.5
Gemma-12B
62.5
58.25
23.25
63.25
Gemma-27B
71.0
60.0
25.75
64.5
Qwen-4B (W/O Thinking)
64.0
66.0
25.25
60.75
Qwen-35B (W/O Thinking)
75.0
71.75
35.75
73.75
Table 5: Behavioral and cognitive task accuracy (%). Bold marks the best model score in each column; underlining marks the best score within each multi-row model block, including ties, with Qwen thinking modes treated separately. Human (avg/best) reports the mean/columnwise maximum across three participants.
Appendix figures & tables16 assets
Supplementary material from the paper’s appendix.
Appendix
Dimension
Fleiss’ κ
Krippendorff’s α
Belief
0.911
0.911
Emotion
0.622
0.625
Intent
0.708
0.711
Appendix
Table 6: Multi-annotator agreement across all three annotators (A, B, and C) jointly, using two complementary reliability metrics.
Dimension
Gold Correctness
Distractor Plausibility
Belief
4.775 ± 0.474
4.575 ± 0.628
Emotion
4.517 ± 0.866
4.258 ± 0.780
Intent
4.750 ± 0.520
4.558 ± 0.739
Overall
4.681 ± 0.650
4.464 ± 0.716
Appendix
Table 7: Human evaluation of gold answer correctness and distractor plausibility using a 5-point Likert scale, with the third utterance visible to annotators. Values are reported as mean ± standard deviation.
Figure 2: Distribution of choice A versus choice B on the behavioral intelligence task, for each model and human annotator. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 3: Absolute pairwise difference in %A between all evaluated models and human annotators on the behavioral intelligence task. The dagger symbol ( † ) denotes models evaluated with thinking enabled. Model proportions are computed over all instances, whereas human proportions are computed on the instances shown to the annotators; differences involving human annotators should therefore be interpreted with caution.
Figure 4: Distribution of choices A, B, C, and D for the belief dimension of the cognitive intelligence task, for each model and human annotator. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 5: Pairwise Pearson correlation of answer-choice distributions between all evaluated models and human annotators, for the belief dimension of the cognitive intelligence task. Correlations involving human annotators are computed on shared instances. Blank cells indicate undefined correlations, which occur when a distribution computed on the shared instances is exactly uniform. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 6: Distribution of choices A, B, C, and D for the emotion dimension of the cognitive intelligence task, for each model and human annotator. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 7: Pairwise Pearson correlation of answer-choice distributions between all evaluated models and human annotators, for the emotion dimension of the cognitive intelligence task. Correlations involving human annotators are computed on shared instances. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 8: Distribution of choices A, B, C, and D for the intent dimension of the cognitive intelligence task, for each model and human annotator. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Figure 9: Pairwise Pearson correlation of answer-choice distributions between all evaluated models and human annotators, for the intent dimension of the cognitive intelligence task. Correlations involving human annotators are computed on shared instances. The dagger symbol ( † ) denotes models evaluated with thinking enabled.
Topic
Count
%
Ethics & Morality
60
30.0
Politics & Government
45
22.5
Society & Culture
34
17.0
Philosophy & Religion
30
15.0
Economics & Business
9
4.5
Science & Technology
7
3.5
Appendix
Table 8: Topic distribution of the 200 CMV threads in PerSo .
Method
Accuracy (%)
± Std
Behavioral task ( n=200 )
Random baseline
50.0
–
Length heuristic
65.5
–
Logistic Regression
68.0
8.9
Random Forest
65.5
4.3
Gradient Boosting
63.5
5.4
Appendix
Table 9: Non-LLM baseline results. Std is computed across the five cross-validation folds; deterministic methods have none.
Figure 19
Figure 12: Random Forest feature importance on the behavioral task. Each feature is the difference between its values for the two candidate replies.
Model
Full (200)
Filtered (167)
Gemma-4B
60.50
56.29
Gemma-12B
62.50
59.88
Gemma-27B
71.00
67.66
Qwen-4B
64.00
57.49
Qwen-35B
75.00
70.06
Qwen-397B
76.00
71.26
Appendix
Table 10: Behavioral accuracy (%) on the full dataset and on the filtered subset obtained by removing instances with an extreme length difference between the two replies (length ratio above Q3). † denotes models evaluated with thinking enabled.
Figure 17: A processed example illustrating how a paired persuasion branch is converted into the cognitive and behavioral tasks.