Large language models (LLMs) has been widely used for automated negotiation, but their high computational cost and privacy risks limit deployment in privacy-sensitive, on-device settings such as mobile assistants or rescue robots. Small language models (SLMs) offer a viable alternative, yet struggle with the complex emotional dynamics of high-stakes negotiation. We introduces EmoMAS, a Bayesian multi-agent framework that transforms emotional decision-making from reactive to strategic. EmoMAS leverages a Bayesian orchestrator to coordinate three specialized agents: game-theoretic, reinforcement learning, and psychological coherence models. The system fuses their real-time insights to optimize emotional state transitions while continuously updating agent reliability based on negotiation feedback. This mixture-of-agents architecture enables online strategy learning without pre-training. We further introduce four high-stakes, edge-deployable negotiation benchmarks across debt, healthcare, emergency response, and educational domains. Through extensive agent-to-agent simulations across all benchmarks, both SLMs and LLMs equipped with EmoMAS consistently surpass all baseline models in negotiation performance while balancing ethical behavior. These results show that strategic emotional intelligence is also the key driver of negotiation success. By treating emotional expression as a strategic variable within a Bayesian multi-agent optimization framework, EmoMAS establishes a new paradigm for effective, private, and adaptive negotiation AI suitable for high-stakes edge deployment.
Figures & tables
Figure 1: Illustration of the workflow of the EmoMAS framework.
Datasets
Negotiator Models
Success Rate (%) ↑
Negotiation Outcomes (%) ↑
Negotiation Rounds ( ↓ )
GPT-4o-mini
Qwen-7B
GPT-4o-mini
Qwen-7B
GPT-4o-mini
Qwen-7B
CRAD (Debt)
Vanilla
90.0
85.0
14.5 [9.7-20.1]
12.6 [7.9-18.1]
15.0 [13.1-17.7]
17.6 [14.5-20.6]
Vanilla+Prompt
90.0
80.0
14.5 [9.8-20.8]
12.8 [8.1-18.5]
15.7 [13.5-17.6]
17.4 [15.1-21.2]
Game Theory
95.0
70.0
14.7 [9.9-20.5]
8.9 [4.7-13.9]
15.1 [12.8-17.1]
20.1 [16.4-23.5]
Q-Learning
90.0
75.0
14.2 [9.8-19.3]
11.5 [6.5-17.5]
15.8 [13.4-17.7]
16.5 [13.7-19.2]
Coherence
85.0
80.0
13.8 [8.7-19.8]
12.4 [7.4-18.5]
16.1 [14.9-21.5]
16.8 [13.9-19.5]
Table 1: Performance comparison of EmoMAS and baselines (using GPT - 4o - mini and Qwen - 7B) against vanilla GPT - 4o - mini opponents across four scenarios (mean with 95% confidence interval). Best results for each scenario are highlighted in bold .
Opponent Strategies
Negotiator Models
Success Rate (%) ↑
Negotiation Outcomes (%) ↑
Negotiation Rounds ( ↓ )
SSD
SSAD
SSD
SSAD
SSD
SSAD
Pressuring
Vanilla
20.0
70.0
18.8 [11.3-27.1]
1.9 [1.2-2.6]
13.7 [10.8-16.6]
7.6 [2.6-11.0]
Game Theory
32.0
64.0
14.1 [8.5-21.8]
0.6 [0.3-1.1]
12.5 [9.8-15.2]
8.9 [3.8-13.6]
Q-Learning
42.0
76.0
24.0 [14.5-35.1]
0.3 [0.1-0.8]
15.6 [12.8-19.4]
8.9 [4.1-15.6]
EmoMAS-Bayes
50.0
80.0
28.0 [17.8-42.1]
2.4 [1.7-3.8]
13.8 [10.5-15.2]
7.8 [1.8-8.6]
Playing Victim
Vanilla
58.0
80.0
55.4 [44.6-65.8]
1.7 [1.2-2.9]
11.2 [8.5-14.0]
5.5 [2.6-8.8]
Table 2: Performance comparison of EmoMAS and baselines (using GPT - 4o - mini) against GPT - 4o - mini opponents employing advanced strategies across medical and educational scenarios (mean with 95% confidence interval). Best values for each scenario-opponent strategy combination are highlighted in bold .
Negotiator Models
Opponent Strategies
Opponent Model (Qwen-1.5B)
Success Rate (%) ↑
Negotiate Rates (%) ↑
Negotiation Rounds ( ↓ )
Qwen-1.5B
Vanilla
90.0
91.5 [81.5-100.0]
9.6 [6.1-13.2]
Coherence
72.0
85.1 [57.4-100.0]
14.1 [10.1-19.9]
Game Theory
86.0
88.7 [73.7-100.0]
11.9 [8.3-15.8]
Q-Learning
94.0
90.9 [79.6-100.0]
12.9 [9.3-16.1]
EmoMAS-LLM
92.0
89.5 [69.8-100.0]
9.8 [6.6-15.4]
Table 3: Evaluation results of EmoMAS and baselines (Qwen-1.5B) against GPT - 4o - mini and Qwen-1.5B opponents under the emergency scenario (mean with 95% confidence interval). Best results for each opponent model are highlighted in bold .
Opponent Strategies
Negotiator Models
Emotional Tracking (%) ↑
Emotional Consistency (%) ↑
Manipulation Rate (%) ↓
Qwen-1.5B
GPT-4o-mini
Qwen-1.5B
GPT-4o-mini
Qwen-1.5B
GPT-4o-mini
Pressuring
Game Theory
87.3
95.6
53.5
64.7
69.5
61.5
Q-Learning
85.8
91.5
53.1
65.7
71.8
56.3
Coherence
86.7
94.6
83.5
90.2
53.6
42.4
EmoMAS-Bayes
89.5
95.6
63.5
78.6
64.5
51.4
Table 4: Behavioral analysis and comparison of EmoMAS and baselines (Qwen - 1.5B vs. GPT - 4o - mini) against GPT - 4o - mini opponents on the DESRD dataset. Best results are highlighted in bold .
Appendix figures & tables22 assets
Supplementary material from the paper’s appendix.
Appendix
joy
sadness
anger
fear
surprise
disgust
neutral
joy
(4,4)
(2,3)
(1,2)
(2,1)
(3,3)
(2,2)
(3,3)
sadness
(3,2)
(3,3)
(1,2)
(2,1)
(2,2)
(1,1)
(2,3)
anger
(2,1)
(2,1)
(1,1)
(1,0)
(1,2)
(0,1)
(1,2)
fear
(1,2)
(1,2)
(0,1)
(2,2)
(1,2)
(0,1)
(2,3)
surprise
(3,3)
(2,2)
(2,1)
(2,1)
(4,4)
(1,2)
(3,3)
disgust
(2,2)
(1,1)
(1,0)
(1,0)
(2,1)
(2,2)
(2,2)
Appendix
Table 5: Payoff matrix for emotion interactions. Each matrix entry (x,y) represents (client payoff, agent payoff).
Field Name
Data Type
Description
Case_ID
Integer
Unique case identifier (1-100).
Creditor_Name
String
Name of the creditor institution.
Debtor_Name
String
Name of the debtor institution.
Credit_Type
String
Loan category: Working Capital Loan, Equipment Financing, Commercial Mortgage, etc. (8 distinct types).
Original_Amount_USD
Float
Initial principal amount of the loan (in US dollars).
Outstanding_Balance_USD
Float
Current unpaid debt balance (fixed at 15,700 USD across all samples).
Appendix
Table 6: Description of the Variables in the CRAD Dataset.