In this paper we study the small-world network model of Watts and Strogatz, which mimics some aspects of the structure of networks of social interactions. We argue that there is one non-trivial length-scale in the model, analogous to the correlation length in other systems, which is well-defined...

We consider a model of platform adaptation in spatial voting focussing on the effect of abstention on the stability of the mean voter equilibrium. Two distinct approaches for modeling abstention are explored: (1) voters abstain if party platforms are too similar to each other and (2) voters...

How do organisms communicate honestly despite conflicts of interest? Over the past quarter-century, the "costly signalling" hypothesis -- that signal honesty can be ensured by appropriate signal cost -- has emerged as the dominant explanation for this puzzle. First proposed by Zahavi [1, 2] and...

The following model of political process is intended to be a moderately realistic representation of Florentine republicanism, during the period of the Renaissance (ca. 1300-1500). The model is composed of two parts: (a) patronage - namely, the building up of partisan networks through the...

We critique the measure of complexity introduced by Shiner, Davison, and Landsberg in Ref. [1]. In particular, we point out that it is over-universal, in the sense that it has the same dependence on disorder for structurally distinct systems. We also point out a misinterpretation of a result...

Stability and diversity are two key properties that living entities share with spin glasses, where they are manifested through the breaking of the phase space into many valleys or local minima connected by saddle points. The topology of the phase space can be conveniently condensed into a tree...

Models of habitat fragmentation have mainly explored the effects on a few species ecologies or on a hierarchical community of competitors. These models reveal that, under different conditions, ecosystem response can underly sharp changes when some given thresholds are reached. Here we explore...

We show that the problem of designing RNA sequences that can fold into multiple stable secondary structures can be transformed into a combinatorial optimization problem that can be solved by means of simple heuristics. Hence it is feasible to design RNA switches with prescribed strucutral...

This paper provides an analysis of aggregate behavioral outcomes when individual utility exhibits social interaction effects. We study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behavior of others in an...