江苏省应用数学（中国矿业大学）中心系列学术报告
报告题目：Consensus Formation and Change are Enhanced by Neutrality
报告专家：Tim Rogers 英国巴斯大学教授
报告地点：数学学院A321
报告摘要：Effective collective decision-making in human and animal groups requires robust mechanisms for consensus formation and change, typically via feedback loops in which individuals adapt their behavior and opinions based on their perception of others. Such processes have been observed in the onset of motion in insect swarms and are believed to manifest across scales from nucleosomes to entire societies. However, levels of participation can be highly variable over time, with individuals sometimes adopting neutral positions such as moving to the back of a group or abstaining from a vote. Here, we present a new theoretical and experimental analysis showing that neutrality has two important and hitherto unreported benefits to collective decision-making. First, it enables the robust formation of consensus in groups of individuals applying simple linear reasoning, updating their stance after consideration of at most one other individual at a time. Second, we find that neutral actors can facilitate efficient consensus change by reducing the effective population size during transitions. These findings are derived from a new general mathematical model of collective binary decision problems and validated against experiments with insect and human populations. Our results provide a parsimonious explanation of how groups of animals and humans quickly reach and overturn consensus, suggesting efficient solutions to collective decision-making problems.
Tim Rogers教授，英国巴斯大学数理科学系主任。Tim Rogers教授长期从事网络动力学以及生态系统稳定性的研究，在 Science、Nature Physics、Nature Communications、PNAS、Physical Review Letters等国际权威期刊发表论文70余篇，H指数为 22。承担英国皇家学会（Royal Society）、工程与物理科学研究委员会（EPSRC）、伦敦数学学会（LMS）科研项目十余项，并担任 《Royal Society Open Science》编辑。因其在生物数学中的原创性贡献，获英国应用数学学会颁发的跨学科研究奖。