Professor Li Jianbiao’s Team Uncovers the Deep Mechanism of "Ephemeral Connections" Driving Long-term Cooperation

The widespread application of digital technologies has facilitated brief and frequent cross-regional interactions among individuals. Such "ephemeral connections" not only greatly expand the temporal and spatial boundaries of interpersonal communication but also exert a profound impact on the emergence and maintenance of cooperative behavior. However, systematic research on this phenomenon remains relatively limited in behavioral science, network science, and socio-economic fields. Recently, the team led by Professor Li Jianbiao from the School of Economics/Institute for the Study of Brain-Like Economics at Shandong University has made important progress in this field. They innovatively proposed an integrated framework of "ephemeral connections-historical interactions" and revealed the promotion law and internal mechanism of ephemeral connections on the emergence of cooperation. The relevant research paper titled Ephemeral Connections, Persistent Effects: Cooperation Dynamics in Temporal Networks with Historical Interactions has been published online in Chaos, Solitons & Fractals, a high-level international interdisciplinary journal under Elsevier. The paper was co-authored by Associate Professor Xie Yunya from Tianjin University of Finance and Economics (visiting scholar at Shandong University), Professor Li Jianbiao from the School of Economics/Institute for the Study of Brain-Like Economics at Shandong University, and doctoral student Wang Yue. Associate Professor Xie Yunya is the first author, and Professor Li Jianbiao is the corresponding author.

Based on the theoretical framework integrating historical interactions between individuals and existing connections with new ephemeral connections, this study constructed a game model of co-evolution between strategies and network topologies, focusing on the impacts of connection thresholds, historical memory length, social capacity, and connection costs on the emergence of cooperation. The results show that ephemeral connections can effectively break the locking effect of defection equilibrium in individual interactions and promote the formation of cooperative clusters. The paper further reveals its internal mechanism from two perspectives: ephemeral connections promoting individuals to cooperate with original neighbors and facilitating the continuous assimilation of edge nodes of cooperative clusters. Multi-agent simulations further indicate that improving social capacity and connection costs contributes to the formation of cooperation, while over-reliance on historical information or frequent establishment of new connections is not conducive to the maintenance of cooperative behavior.

Professor Li Jianbiao from Shandong University, the corresponding author of the paper, pointed out: "Although ephemeral connections seem random and fragile, when combined with memory mechanisms, they can effectively leverage the dynamic balance of cooperation. They are like 'emerging opportunities' in society, stimulating individuals to reflect on and adjust existing relationships."

This research not only deepens our understanding of cooperation mechanisms in social networks but also provides theoretical guidance for digital platform design, interpersonal network design, and organizational governance. The research was supported by the Major Program, Key Program of the National Social Science Fund of China, the National Natural Science Foundation of China, and the Natural Science Foundation of Shandong Province.

The team of the Institute for the Study of Brain-Like Economics at Shandong University led by Professor Li Jianbiao is committed to interdisciplinary research in neuroeconomics, neurofinance, neuromanagement, and artificial intelligence economics. The institute aims to meet international standards, catch up with world frontiers, lead the innovative development of neuroeconomics, and contribute to the construction of the national "New Liberal Arts". Research achievements have been widely published in many top academic journals at home and abroad, including PNAS, Management Science, Journal of Economic Behavior & Organization, Experimental Economics, and Economic Research Journal.