Individual and collective gains from cooperation and reciprocity in a dynamic-network Prisoner’s Dilemma driven by extraversion, openness, and agreeableness

Abián, David (Universidad de Zaragoza) ; Bernad, Jorge ; Ilarri, Sergio (Universidad de Zaragoza) ; Trillo-Lado, Raquel (Universidad de Zaragoza)

Resumen: How do stable personality differences shape cooperation when social ties can form and dissolve? We model a repeated Prisoner’s Dilemma on an endogenous network in which three continuous Big Five traits map to transparent local mechanisms: Extraversion sets a target number of partners, Openness determines how broadly agents search beyond friends-of-friends, and Agreeableness sets a baseline willingness to cooperate. At each encounter, agents combine this baseline with the partner’s directly observed history; there are no trait labels, gossip, or global reputations. Ties form when agents are under-connected and are cut when they become over-connected, with cuts prioritising partners who have defected more often. We vary network size (N=30–200), population composition, and the balance between trait-driven and history-driven behaviour. Three robust patterns emerge. First, cooperate first, then reciprocate—high initial willingness to cooperate combined with history-sensitive response—produces systems that are simultaneously more prosperous, fairer, and safer. Second, personality has predictable conditional effects: Agreeableness helps when history matters but hurts when behaviour is mostly trait-driven; Extraversion amplifies the environment; Openness has little net payoff effect. Third, the network reorganises accordingly: degree assortativity stays near zero, whereas agreeable agents increasingly connect to one another when cooperation takes hold.

Idioma: Inglés

DOI: 10.1038/s41598-026-49942-w

Año: 2026

Publicado en: Scientific reports (Nature Publishing Group) (2026), [14 pp.]
ISSN: 2045-2322

Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2020-113037RB-I00
Financiación: info:eu-repo/grantAgreement/ES/AEI/PID2020-113903RB-I00
Financiación: info:eu-repo/grantAgreement/ES/DGA/T42-23R
Financiación: info:eu-repo/grantAgreement/ES/DGA/T64-23R

Tipo y forma: Article (Published version)

Área (Departamento): Área Lenguajes y Sistemas Inf. (Dpto. Informát.Ingenie.Sistms.)