LLM-Agent-based Social Simulation for Attitude Diffusion

Abstract: This paper introduces discourse_simulator, an open-source framework that combines LLMs with agent-based modelling. It offers a new way to simulate how public attitudes toward immigration change over time in response to salient events like protests, controversies, or policy debates. LLMs are used to generate social media posts, interpret opinions, and model how ideas spread through social networks. Unlike traditional agent-based models that rely on fixed, rule-based opinion updates and cannot generate natural language or consider current events, this approach integrates multidimensional sociological belief structures and real-world event timelines. This framework is wrapped into an open-source Python package that integrates generative agents into a small-world network topology and a live news retrieval system. discourse_sim is purpose-built as a social science research instrument specifically for studying attitude dynamics, polarisation, and belief evolution following real-world critical events. Unlike other LLM Agent Swarm frameworks, which treat the simulations as a prediction black box, discourse_sim treats it as a theory-testing instrument, which is fundamentally a different epistemological stance for studying social science problems. The paper further demonstrates the framework by modelling the Dublin anti-immigration march on April 26, 2025, with N=100 agents over a 15-day simulation. Package link: https://pypi.org/project/discourse-sim/

• The paper presents the discourse_simulator, an LLM-based framework that integrates agents with natural language reasoning into ABMs for studying attitude diffusion.
• It employs multidimensional belief structures and an Observe–Think–Act loop, using real-time news and empirical survey data to simulate realistic social influence and opinion shifts.
• The framework is theory-driven and reproducible, offering granular agent logging and calibration that enhance the reliability and transparency of socio-political simulations.

LLM-Agent-Based Social Simulation for Attitude Diffusion: A Technical Review

Framework Overview and Motivation

The paper "LLM-Agent-based Social Simulation for Attitude Diffusion" (2604.03898) presents the discourse_simulator, an open-source Python framework integrating LLM-driven generative agents into agent-based models (ABM) for studying complex social phenomena, specifically attitudes toward immigration following critical events. Unlike conventional ABM approaches, the framework introduces agents that reason, communicate, and evolve in natural language, grounded on empirical event timelines and real-time news retrieval. By embedding multidimensional sociological belief structures informed by political science and survey data, the framework allows targeted investigation of opinion shifts, polarization, and discourse evolution that are typically oversimplified in classical pairwise-update models.

Advances Over Prior Models

This framework addresses several limitations of prior ABM and LLM-augmented simulations:

• Multidimensional Attitude Representation: Agent stances are decomposed into independent economic, cultural, security, and humanitarian belief dimensions, overcoming the typical one-dimensional scalar representations in traditional ABMs and capturing the complexity observed in empirical studies.
• Empirical Agent Calibration: Distributions for agent 'kind' (centrist, pro-immigration, far-right, media) are grounded in actual survey sources (ESRI, LSE, Eurobarometer), rather than arbitrary or even splits, matching the 2025 Irish sociopolitical context.
• OTA Loop with Real-World Input: Agents operate within an "Observe–Think–Act" (OTA) reasoning loop, retrieving live news via DuckDuckGo and synthesizing day-specific memory and peer communication, ensuring contextual and longitudinal realism not present in most synthetic news-based simulations.
• Transparent, Theory-Driven Design: All agent parameters and belief-updating mechanisms are guided by explicit theoretical referents, spanning bounded confidence (Hegselmann–Krause, Deffuant), persuasive communication models, affective intelligence, and homophily theory, combining rigor with controllability.

Agent Architecture and Social Dynamics

Agents in discourse_simulator are specified as Python dataclasses with static and dynamic attributes reflecting identity, psychological profile, belief components, and behavioral history. The belief update mechanism integrates:

• News Salience: The impact of real-world news is mapped into the multi-dimensional belief vector via a keyword-based salience mechanism, modulated by agent-specific openness and emotional reactivity, affecting components such as security threat and humanitarian concern.
• Peer Influence: Agents are embedded within a Watts-Strogatz small-world graph, and beliefs are updated by peer mean attitude, scaled by conformity and trust factors. The magnitude of peer pull is bounded and directionally correct, enforcing realistic echo-chamber dynamics.
• Mood Dynamics: Short-term affect (mood) is updated with news shocks and temporal decay, providing further affect-driven inertia and reflecting observed psychological adaptation rates.
• Belief Inertia: The propensity to resist or adopt new information (psychological anchoring) is parameterized via openness, affecting the weighting between previous attitude and new evidence from self-posts, peers, and beliefs.

The final attitude update explicitly integrates (1) own current post's LLM-scored stance (self-reinforcement), (2) peer network pressure, (3) composite beliefs, and (4) psychological inertia, all clipped to a normalized range. This multidimensional, multi-source update mechanism ensures that both endogenous (memory, profile) and exogenous (peers, media) factors drive opinion evolution.

Simulation Methodology

The primary demonstration simulates 100 agents over a 15-day window surrounding a large-scale anti-immigration protest in Dublin (April 26, 2025). All agents share the fundamental event context, but individuality emerges from prior distributions, memory construction, and daily exposure to authenticated news developments, classified into evidence tiers. Each day, agents:

• Retrieve and synthesize contextually relevant news.
• Recall and incorporate the last five self-posts for narrative continuity.
• Optionally analyze text for sentiment/confidence.
• Generate a 40-word social media post grounded in the above.
• Undergo post hoc LLM-based interpretive scoring to quantify stance.

This sequence avoids overnight attitude flips and constrains evolution to be gradual, a key model fidelity requirement.

Distinguishing Features and Methodological Rigor

The framework makes several explicitly stated epistemological and methodological advancements:

• Theory-Testing Instrument: Simulations are designed for theory falsification and comparison, not prediction black-boxing. This sharpens the tool for hypothesis-driven social science.
• Live Empirical Grounding: The real-time news retrieval ensures agents are not evolving discourse in an information vacuum, mitigating one of the strongest critiques of prior generative ABMs.
• Full Reproducibility: Use of random seeds, deterministic scoring modes, and empirical agent proportioning foster high replicability.
• Granular Agent Logging: Attitude histories, reasoning traces, and message logs facilitate granular post hoc analysis at both micro (agent) and macro (aggregate polarization, exposure trajectories) levels.

Numerical and Qualitative Results

While the framework is demonstrated, the paper highlights several strong capabilities without overstating predictive power:

• Validated Belief Evolution: The incorporation of peer and media influences causes distributions of attitudes and polarization to evolve in a manner sensitive to both real event stimuli and peer structure.
• Resilience to Pathological Consensus: By explicitly modeling confirmation bias and using kind-specific priors, the framework avoids the rapid consensus convergence observed in prior LLM AMB studies [e.g., Chuang et al., 2023].
• Separation of Channels: By decomposing beliefs, the model supports hypothetical interventions on specific discourse channels (e.g., assessing if security threats versus humanitarian frames have greater downstream influence on collective attitude).
• Transparent Metric Output: Outputs as Pandas DataFrames with serialized agent traces directly support further statistical or causal inference analysis.

Theoretical and Practical Implications

The discourse_simulator platform establishes a template for:

• Empirically Anchored, LLM-Augmented Simulations: The approach can be generalized to other public attitude domains (e.g., climate, war, economic shocks) provided credible belief decomposition and data sources exist.
• Testing Social Influence Theories: Micro–macro linkage allows for experimental falsification of classic hypotheses about rumor spread, polarization, or consensus in heterogeneous populations.
• LLM Robustness Evaluation: By decoupling reasoning and tool interfaces, the framework is model-agnostic and suitable for benchmarking LLMs outside of proprietary tool schemas.
• Simulation Transparency: Researchers can audit agent reasoning and calibrate component weights, enhancing trust in simulation outputs and interpretability.

However, validation and interpretability challenges remain; the flexibility of generative ABMs confounds straightforward empirical matching, and real-case predictive validity cannot be assured. The reliance on LLMs introduces inherent model biases and necessitates ongoing scrutiny regarding their suitability for simulating human social cognition.

Future Directions

Potential extensions include scaling to larger networks, increasing agent behavioral heterogeneity, testing alternative peer influence models, integrating additional event types, or benchmarking LLM variants for linguistic and reasoning quality. Incorporation of more nuanced psychological constructs (e.g., longitudinal memory, out-group empathy, digital echo chambers) may further enhance fidelity. The broader community could use the framework for comparative studies or as a modular component within hybrid ABM architectures.

Conclusion

discourse_simulator represents a methodologically rigorous and transparent integration of empirical social science, ABM tradition, and LLM-generated agent simulation. By embedding agents with empirically calibrated psychological depth and grounding day-by-day discourse generation in authenticated critical events, the framework marks a significant step toward sociologically valid, theory-driven generative simulations. It provides a robust foundation for investigating attitude diffusion, polarization, and social influence processes in complex, event-driven contexts.