Highlights

Emergence of consensus as a modular-to-nested transition in communication dynamics

Scientific Reports 7, 41673 (2017).

Consensus

Online social networks have transformed the way in which humans communicate and interact, leading to a new information ecosystem where people send and receive information through multiple channels, including traditional communication media. Despite many attempts to characterize the structure and dynamics of these techno-social systems, little is known about fundamental aspects such as how collective attention arises and what determines the information life-cycle. Current approaches to these problems either focus on human temporal dynamics or on semiotic dynamics. In addition, as recently shown, information ecosystems are highly competitive, with humans and memes striving for scarce resources –visibility and attention, respectively. Inspired by similar problems in ecology, here we develop a methodology that allows to cast all the previous aspects into a compact framework and to characterize, using microblogging data, information-driven systems as mutualistic networks. Our results show that collective attention around a topic is reached when the user-meme network self- adapts from a modular to a nested structure, which ultimately allows minimizing competition and attaining consensus. Beyond a sociological interpretation, we explore such resemblance to natural mutualistic communities via well-known dynamics of ecological systems.

J. Borge-Holthoefer, R. A. Baños, C. Gracia-Lazaro and Y. Moreno, “Emergence of consensus as a modular-to-nested transition in communication dynamics”, Scientific Reports 7, 41673 (2017). Supplementary Material


Social Movements

The recent wave of mobilizations in the Arab world and across Western countries has generated much discussion on how digital media is connected to the diffusion of protests.

We examine that connection using data from the surge of mobilizations that took place in Spain in May 2011. We study recruitment patterns in the Twitter network and find evidence of social influence and complex contagion. We identify the network position of early participants (i.e. the leaders of the recruitment process) and of the users who acted as seeds of message cascades (i.e. the spreaders of information). We find that early participants cannot be characterized by a typical topological position but spreaders tend to me more central to the network. These findings shed light on the connection between online networks, social contagion, and collective dynamics, and offer an empirical test to the recruitment mechanisms theorized in formal models of collective action.

Project4: Structure and Dynamics

The recent wave of mobilizations in the Arab world and across Western countries has generated much discussion on how digital media is connected to the diffusion of protests. We examine that connection using data from the surge of mobilizations that took place in Spain in May 2011. We study recruitment patterns in the Twitter network and find evidence of social influence and complex contagion. We identify the network position of early participants (i.e. the leaders of the recruitment process) and of the users who acted as seeds of message cascades (i.e. the spreaders of information). We find that early participants cannot be characterized by a typical topological position but spreaders tend to me more central to the network. These findings shed light on the connection between online networks, social contagion, and collective dynamics, and offer an empirical test to the recruitment mechanisms theorized in formal models of collective action.

This study is a follow-up work of our first incursion into the subject of online social networks and the diffusion of protests.
See what follows for more details.


This work represents our first contribution to a subject that has attracted a lot of interest in the last few years: the analysis of online social networks. The number of people using online social networks in their everyday life is continuously growing at a pace never saw before. This new kind of communication has an enormous impact on opinions, cultural trends, information spreading and even in the commercial success of new products. More importantly, social online networks have revealed as a fundamental organizing mechanism in recent country-wide social movements. In this study, we provide a quantitative analysis of the structural and dynamical patterns emerging from the activity of an online social network around the ongoing May 15th (15M) movement in Spain. Our network is made up by users that exchanged tweets in a time period of one month, which includes the birth and stabilization of the 15M movement. We characterize in depth the growth of such dynamical network and find that it is scale-free with communities at the mesoscale. We also find that its dynamics exhibits typical features of critical systems such as robustness and power-law distributions for several quantities. Remarkably, we report that the patterns characterizing the spreading dynamics are asymmetric, giving rise to a clear distinction between information sources and sinks. Our study represents a first step towards the use of data from online social media to comprehend modern societal dynamics.

 

J. Borge-Holthoefer, R. A. Baños, S. González-Bailón and Y. Moreno, “Cascading Behavior in Complex Socio-technical Networks”, Journal of Complex Networks 1, 3-24 (2013); doi: 10.1093/comnet/cnt006.

S. Gonzalez-Bailon, J. Borge-Holthoefer, A. Rivero, and Y. Moreno, “The Dynamics of Protest Recruitment through an Online Network”, Scientific Reports 1, 197 (2011).

J. Borge-Holthoefer, A. Rivero, I. García, E. Cauhe, A. Ferrer, D. Ferrer, D. Francos, D. Iñiguez, M. P. Pérez, G. Ruiz, F. Sanz, F. Serrano, C. Viñas, A. Tarancón, and Y. Moreno, “Structural and Dynamical Patterns on Online Social Networks: the Spanish May 15th Movement as a case study”, PLoS ONE 6(8): e23883 (2011).

Transition from reciprocal cooperation to persistent behaviour in social dilemmas at the end of adolescence

Transition from reciprocal cooperation to persistent behaviour in social dilemmas at the end of adolescence. Nature Communications 5:4362 (2014)

In this paper, we find that the average amount of cooperativeness is independent of age except for the elderly, who cooperate more, and a behavioural transition from reciprocal, but more volatile behavior to more persistent actions towards the end of adolescence.

Transition from reciprocal cooperation to persistent behaviour in social dilemmas at the end of adolescenceWhile human societies are extraordinarily cooperative in comparison with other social species, the question of why we cooperate with unrelated individuals remains open. Here we report results of a lab-in-the-field experiment with people of different ages in a social dilemma. We find that the average amount of cooperativeness is independent of age except for the elderly, who cooperate more, and a behavioural transition from reciprocal, but more volatile behaviour to more persistent actions towards the end of adolescence. Although all ages react to the cooperation received in the previous round, young teenagers mostly respond to what they see in their neighbourhood regardless of their previous actions. Decisions then become more predictable through midlife, when the act of cooperating or not is more likely to be repeated. Our results show that mechanisms such as reciprocity, which is based on reacting to previous actions, may promote cooperation in general, but its influence can be hindered by the fluctuating behaviour in the case of children.

M. Gutierrez-Roig, C. Gracia-Lazaro, J. Perello, Y. Moreno, and A. Sanchez, “Behavioral transition with age in social dilemmas: From reciprocal youth to persistent response in adulthood”, Nature Communications 5:4362, doi:10.1038/ncomms5362 (2014).