Suchergebnisse

The level of antagonism between political groups has risen in the past years. Supporters of a given party increasingly dislike members of the opposing group and avoid intergroup interactions, leading to homophilic social networks. While new connections offline are driven largely by human decisions, new connections on online social platforms are intermediated by link recommendation algorithms, e.g., "People you may know" or "Whom to follow" suggestions. The long-term impacts of link recommendation in polarization are unclear, particularly as exposure to opposing viewpoints has a dual effect: Connections with out-group members can lead to opinion convergence and prevent group polarization or further separate opinions. Here, we provide a complex adaptive–systems perspective on the effects of link recommendation algorithms. While several models justify polarization through rewiring based on opinion similarity, here we explain it through rewiring grounded in structural similarity—defined as similarity based on network properties. We observe that preferentially establishing links with structurally similar nodes (i.e., sharing many neighbors) results in network topologies that are amenable to opinion polarization. Hence, polarization occurs not because of a desire to shield oneself from disagreeable attitudes but, instead, due to the creation of inadvertent echo chambers. When networks are composed of nodes that react differently to out-group contacts, either converging or polarizing, we find that connecting structurally dissimilar nodes moderates opinions. Overall, our study sheds light on the impacts of social-network algorithms and unveils avenues to steer dynamics of radicalization and polarization in online social networks.

From work contracts and group buying platforms to political coalitions and international climate and economical summits, often individuals assemble in groups that must collectively reach decisions that may favor each part unequally. Here we quantify to which extent our network ties promote the evolution of collective fairness in group interactions, modeled by means of Multiplayer Ultimatum Games (MUG). We show that a single topological feature of social networks-which we call structural power-has a profound impact on the tendency of individuals to take decisions that favor each part equally. Increased fair outcomes are attained whenever structural power is high, such that the networks that tie individuals allow them to meet the same partners in different groups, thus providing the opportunity to strongly influence each other. On the other hand, the absence of such close peer-influence relationships dismisses any positive effect created by the network. Interestingly, we show that increasing the structural power of a network leads to the appearance of well-defined modules-as found in human social networks that often exhibit community structure-providing an interaction environment that maximizes collective fairness. ; This research was supported by Fundacao para a Ciencia e Tecnologia (FCT) through grants SFRH/BD/94736/2013, PTDC/EEI-SII/5081/2014, PTDC/MAT/STA/3358/2014 and by multi-annual funding of CBMA and INESC-ID (under the projects UID/BIA/04050/2013 and UID/CEC/50021/2013) provided by FCT. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ...

UID/SOC/04647/2013 ; Electric vehicles (EVs) are a viable alternative to internal combustion engine (ICE) vehi- cles, with the potential to alleviate the negative externalities stemming from the present ICE-based transportation sector. Notwithstanding, the current prevalence of ICE creates a lock-in state that averts the adoption of alternative and environmental friendly technolo- gies, bringing forth a social dilemma. Here we investigate the feasibility of escaping the present lock-in state by studying possible incentive mechanisms involving, simultaneously, governments (public), companies (private) and consumers (civil). Resorting to evolutionary game theory (EGT), we develop a theoretical model grounded on the strategic interactions between players from the different sectors, whose co-evolving choices influence (and are influenced by) different policies and social incentives. Our findings suggest that i) public regulation is necessary but not sufficient for guaranteeing full EV adoption; ii) public-civil synergies are essential; iii) demand for EVs preceding supply is most efficient, providing companies with the needed incentives to counterweigh infrastructure investments; and iv) full adoption of EVs requires coordination between the three sectors to emerge, particu- larly when changes are initiated by the public sector ; authorsversion ; published

The recent rise of the civil sector as a main player of sociopolitical actions, next to public and private sectors, has largely increased the complexity underlying the interplay between different sectors of our society. From urban planning to global governance, analysis of these complex interactions requires new mathematical and computational approaches. Here, we develop a novel framework, grounded on evolutionary game theory, to envisage situations in which each of these sectors is confronted with the dilemma of deciding between maintaining a status quo scenario or shifting towards a new paradigm. We consider multisector conflicts regarding environmentally friendly policies as an example of application, but the framework developed here has a considerably broader scope. We show that the public sector is crucial in initiating the shift, and determine explicitly under which conditions the civil sector-reflecting the emergent reality of civil society organizations playing an active role in modern societies-may influence the decision-making processes accruing to other sectors, while fostering new routes towards a paradigm shift of the society as a whole. Our results are shown to be robust to a wide variety of assumptions and model parametrizations. ; This research was supported and carried out in the framework of the projects: (i) Diffusion of Mass E-Mobility and Integrating Renewable Energy in Smart Grids and Cities: Intelligent Agents for Efficient Energy Consumption, funded by the Israeli Ministry of Energy and Water (S.E., V.B., J.P.); and (ii) by Fundacao para a Ciencia e Tecnologia (FCT) through project grant nos. SFRH/BD/94736/2013 (F.P.S.), PTDC/EEI-SII/5081/2014 (S.E., F.P.S., F.C.S., J.M.P.), PTDC/MAT/STA/3358/2014 ( S.E., F.P.S., F.C.S., J.M.P.) and by multi-annual funding of CBMA, INESC-ID and CICS. NOVA (under the projects UID/BIA/04050/2013, UID/CEC/50021/2013 and UID/SOC/04647/2013) also provided by FCT. ...