We present a spatial agent-based model of the emergence and proliferation of premodern complex societies in an isolated region initially inhabited by simple societies. At the intrasocietal level, the model integrates scalar stress, social fission, sociocultural evolution, societal collapse, and Malthusian-Ricardian demographic dynamics. At the geographical level, the model includes warfare for territory and captives, territorial division due to social conflict, and territorial disintegration due to collapse. We found that a single variableslow, continuous progress in intensive agriculture-drives the social and geographical dynamics. Consistent with the archaeological and historical record, the model produced three consecutive "eras": During the first era, simple societies dominate the region. They use extensive food production methods. Small complex societies of intensive agriculturists emerge intermittently in the core land, where intensification is feasible. Shortly a er, they collapse or are annihilated by local simple societies. During the second era, some complex societies avert early collapse and annihilation. They expand by conquest. At all times, they coexist with simple societies. Some complex societies are destroyed in war; others collapse. From time to time, complex societies collapse en masse. During the third era, there are no more mass collapses. Complex societies slowly expand until they dominate the core land. Simple societies take refuge in the marginal land, where intensification is infeasible. Simple and complex societies coexist, separated by a moving frontier. In an ebb and flow, complex societies expand to the marginal land and withdraw to the core land. The results of the simulations are qualitatively consistent with prehistorical and historical case studies. The model replicates the progression from simple to more complex societies, and explains why that progression happened in fits and starts.

We already know that social network sites (SNS) represent a set of technological capabilities that allow individuals to (i) construct a public or semipublic profile within a bounded system, (ii) articulate a list of other users with whom they share a connection, and (iii) view and traverse their list of connections and those made by others within the system. We also know that these platforms have different functionalities: Some of them emphasize capabilities like photo or video sharing tools, others focus on blogging or instant messaging technologies, whereas others aim to share locations (to name only a few). And, finally, we also know that the presence of these pivotal features afforded by SNS depends on the system design intentions or the intended purpose. Thus, these platforms are designed in terms of “affordances,” a term that suggests how a technology should be used according to the capabilities offered by it. However, it is important to note that, whereas technological affordances refer to the embedded functions in a technology, social affordances refer to the relationships developing within a technical structure. What we do not know yet is the impact that social media affordances may have on romantic relationships.

In the search for balance among their powers in the nomination of members of top-level courts, political actors can design rules that unintendedly introduce political polarization within the judiciary and judges’ reputational concerns can sustain it in the long run. Factoring on the impact of a reform in Chile introduced in 2005 that modifies its Constitutional Court and on the record of its member’s votes between 1990 and 2016, this study finds evidence of an increasing polarization within the Constitutional Court that was unseen during the design of its new rules. In developing countries, in which political institutions -including the judiciary- face lower levels of trust among the citizenry, an increasing level of polarization jeopardizes their survival in the long run. Sign of that process are already in motion in the Chilean case with respect to its Constitutional Court.