arXiv AI
Sep 30

Beyond Symmetric Agents: Cognitive Diversity and Multi-Agent Debate in Small Language Models

The study evaluates multi‑agent debate (MAD) in small language models, testing whether cognitive diversity—via personas, sampling temperature, or model identity—drives performance gains. Across 23 models, five tasks, and over 5,500 runs, MAD consistently outperforms single‑model inference but, when matched for generation budget, it ties or falls behind self‑consistency sampling, with persona prompting actually reducing accuracy. The authors find that MAD’s benefits largely stem from the first answer exchange and that many reported gains are due to ensemble‑sampling effects rather than true diversity, highlighting the need for budget‑matched, contamination‑checked baselines. whyItMatters":"The findings clarify that MAD’s perceived advantages may be overestimated and that future debate mechanisms must be evaluated against rigorous, budget‑matched baselines to ensure genuine performance improvements."

By Leonardo Ferreira, Gardenia Liu, Kaden Zheng
arXiv Computation and Language
Oct 8

The Long Road to the Same Answer: Cognitive Bias Under Escalating Reasoning Budgets in Large Language Models

The study investigates whether large language models (LLMs) that allocate extra computation during inference—termed reasoning models—reduce classic decision biases compared to their non‑reasoning counterparts. Using 30 vignettes covering six cognitive biases and varying token budgets up to 8,192 tokens, the authors find that reasoning models are not less biased, and increased deliberation does not reliably diminish bias magnitude. Only anchoring showed a bias in the human direction, while other biases either remained unchanged or moved further from human patterns, suggesting that test‑time reasoning does not guarantee rationality.

By Obada Kraishan
arXiv AI
1d ago

Not All Test-Time Compute Is Evidence: Model-Specific Bias in LLM Reasoning

The paper argues that additional computation from the same large language model (LLM) during test time does not necessarily provide independent evidence, as errors are correlated across repeated samples, reasoning depth, and self-evaluation. It introduces DIA (Disagreement-triggered Independent Arbitration), which uses disagreement between intermediate and final predictions as a signal of instability and resolves it by having a small panel of heterogeneous models independently solve the question. Across seven benchmarks and two base models, DIA outperforms full chain-of-thought in most settings, achieving significant gains while using fewer tokens and activating only on a subset of examples.

By Ming Shen, Tianjun Yao