Social networks based on dyadic relationships are fundamentally important for understanding of human sociality. However, we have little understanding of the dynamics of close relationships and how these change over time. Evolutionary theory suggests that, even in monogamous mating systems, the pattern of investment in close relationships should vary across the lifespan when post-weaning investment plays an important role in maximising fitness. Mobile phone data sets provide a unique window into the structure and dynamics of relationships. We here use data from a large mobile phone dataset to demonstrate striking sex differences in the gender-bias of preferred relationships that reflect the way the reproductive investment strategies of both sexes change across the lifespan, i.e. women's shifting patterns of investment in reproduction and parental care. These results suggest that human social strategies may have more complex dynamics than previously assumed and a life-history perspective is crucial for understanding them.
The concept of contagion has steadily expanded from its original grounding in epidemic disease to describe a vast array of processes that spread across networks, notably social phenomena such as fads, political opinions, the adoption of new technologies, and financial decisions. (...) We find that the probability of contagion is tightly controlled by the number of connected components in an individual's contact neighborhood, rather than by the actual size of the neighborhood. Surprisingly, once this “structural diversity” is controlled for, the size of the contact neighborhood is in fact generally a negative predictor of contagion. More broadly, our analysis shows how data at the size and resolution of the Facebook network make possible the identification of subtle structural signals that go undetected at smaller scales yet hold pivotal predictive roles for the outcomes of social processes.
Structural diversity in social contagion Johan Ugander, Lars Backstrom, Cameron Marlow, and Jon Kleinberg
Les chercheurs de Facebook, menés par Eytan Bakshy, ont publié une nouvelle étude s’intéressant à comment les gens recevaient et réagissaient à l’information dans le cadre du réseau social. Une étude qui nous invite à “Repenser la diversité de l’information dans les réseaux"
It is very likely that life began with some RNA (or RNA-like) molecules, self-replicating by base-pairing and exhibiting enzyme-like functions that favored the self-replication. Different functional molecules may have emerged by favoring their own self-replication at different aspects. Then, a direct route towards complexity/efficiency may have been through the coexistence/cooperation of these molecules.
Ma W, Hu J (2012) Computer Simulation on the Cooperation of Functional Molecules during the Early Stages of Evolution. PLoS ONE 7(4): e35454. doi:10.1371/journal.pone.0035454
Many researchers have supposed that the emergence of life hinged on a sequence of improbable events, at the same time as they have taken for granted the ability of life on earth to persist indefinitely and to "freeze in" the consequences of early accidents. Smith argues that there is ample evidence for a different interpretation: the emergence of life was an inevitable outcome of geochemistry on the early earth, and the same forces responsible for emergence have continued to support the persistence of life ever since.
With adaptive, complex networks, the evolution of the network topology and the dynamical processes on the network are equally important and often fundamentally entangled. Recent research has shown that such networks can exhibit a ...
Complexity Explained (Springer Complexity): Péter Érdi: Amazon.com: Kindle Store (Complexity Explained: This book explains why complex systems research is important in understanding the structur...)...
The importance of adequately modeling credit risk has once again been highlighted in the recent financial crisis. Defaults tend to cluster around times of economic stress due to poor macro-economic conditions, but also by directly triggering each other through contagion. Although credit default swaps have radically altered the dynamics of contagion for more than a decade, models quantifying their impact on systemic risk are still missing. Here, we examine contagion through credit default swaps in a stylized economic network of corporates and financial institutions
Derivatives and credit contagion in interconnected networks
La complexité n'est-elle pas devenue une caractéristique de nos sociétés, plutôt qu'un bug ? Comment pourrions-nous regagner le contrôle de nos flots d'information, de notre temps ? Pouvons-nous aborder la complexité d'une façon plus productive ? Pouvons-nous mieux la comprendre, mieux la maîtriser ? Tel étaient les questions adressées par les organisateurs de la seconde édition de la conférence Lift France, à la fois à un designer, à un vidéaste et à une ethnologue. Forcément, cela a apporté des réponses multiples.
Two fine authors, Richard Dawkins and Daniel Dennett, have written recent books, The God Delusion and Breaking the Spell arguing against religion. Their views are based on contemporary science. But the largest convictions of contemporary science remain based on reductionism.
I would like to begin a discussion about the first glimmerings of a new scientific world view — beyond reductionism to emergence and radical creativity in the biosphere and human world. This emerging view finds a natural scientific place for value and ethics, and places us as co-creators of the enormous web of emerging complexity that is the evolving biosphere and human economics and culture. In this scientific world view, we can ask: Is it more astonishing that a God created all that exists in six days, or that the natural processes of the creative universe have yielded galaxies, chemistry, life, agency, meaning, value, consciousness, culture without a Creator. In my mind and heart, the overwhelming answer is that the truth as best we know it, that all arose with no Creator agent, all on its wondrous own, is so awesome and stunning that it is God enough for me and I hope much of humankind.
Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks and, as we demonstrate, is capable of capturing the essential features of the structure and the degree of hierarchy in a complex network.