How can evolutionary ideas be applied to the study of social and political institutions? Charles Darwin identified the mechanisms of variation, selection and retention. He emphasized that evolutionary change depends on the uniqueness of every individual and its interactions within a population and with its environment. While introducing the contributions to this special issue, we examine some of the ontological positions underlying evolutionary theory, showing why they are appropriate for studying issues in economics, political science and sociology. We consider how these ideas might help us understand both institutional change and the formation of individual preferences.

Most powerful analytical tools used in the social sciences are well suited for studying static situations. Static and mechanistic analysis, however, is not adequate to understand the changing world in which we live. In order to adequately address the most pressing social and environmental challenges looming ahead, we need to develop analytical tools for analyzing dynamic situations – particularly institutional change. In this paper, we develop an analytical tool to study institutional change, more specifically, the evolution of rules and norms. We believe that in order for such an analytical tool to be useful to develop a general theory of institutional change, it needs to enable the analyst to concisely record the processes of change in multiple specific settings so that lessons from such settings can eventually be integrated into a more general predictive theory of change.

Human communities and ego-centric social networks have a distinct size that reflects a generic relationship between relative neocortex volume and social group size that is characteristic of primates in general (the ‘social brain hypothesis’). Human networks are structured into layers that reflect both differences in the frequency of contact and levels of emotional closeness. The rate of decay in the frequency of contact across network layers is very steep, and we might expect this to have a very significant effect on the likelihood of Ego finding out some novel fact when information flow is limited to face-to-face interaction. I use an analytical model parameterized by these contact frequencies to show that there may be little advantage in having a network larger than ~150 for the purposes of information exchange. I then present a Monte Carlo simulation model to show that structure significantly impedes the rate of information flow in structured communities.

In biology, the laws that regulate the structuring and change of complex organisms, characterised by interlocking complementarities, are different from those that shape the evolution of simple organisms. Only the latter share mechanisms of competitive selection of the fittest analogous to those envisaged by the standard neoclassical model in economics. The biological counterparts of protectionism, subsidies and conflicts enable complex organisms to exit from long periods of stasis and to increase their capacity to adapt efficiently to the environment. Because of their interlocking complementarities, most institutions share the laws governing the structure and change of complex organisms. We concentrate on the complementarities between technology and property rights and consider historical cases in which organisational stasis has been overcome by mechanisms different from (and sometimes acting in spite of) competitive pressure. The evolution of institutions cannot be taken for granted; but even when institutions seem frozen forever by their interlocking complementarities, their potential for change can be discovered by analysis of those interactions.

Generalized Darwinism and self-organization have been positioned as competing frameworks for explaining processes of economic and institutional change. Proponents of each view question the ontological validity and explanatory power of the other. This paper argues that information theory, rooted in modern thermodynamics, offers the potential to integrate these two perspectives in a common and rigorous framework. Both evolution and self-organization can be generalized as computational processes that can be applied to human social phenomena. Under this view, evolution is a process of algorithmic search through a combinatorial design space, while self-organization is the result of non-zero sum gains from information aggregation. Evolution depends on the existence of self-organizing forces, and evolution acts on designs for self-organizing structures. The framework yields insights on the role of agency and the emergence of novelty. The paper concludes that information theory may provide a fundamental ontological basis for economic and institutional evolution.

This paper addresses the issue of how rules are conceptualized by Hodgson in Old Institutional Economics (OIE). The argument is put forward that the concept of rules can be constructively clarified. Rather than provide a general form of single rules within a rule system, we argue for a taxonomic range of single rule forms. This approach has the additional advantage of providing a more explicit account of how rules operate as part of a rule system. It also provides one way to address the fluidity of rules. Rules are understood to be more or less fluid (incomplete) and subject to a practical dynamism. This, we argue, can be differentiated from the idea of tendency based on the capacity of agents not to follow rules. A useful concept here is that of ‘mezzo rules’ or recodifications that both define the rule and distance the agent from their own rule-following behaviour. In pursuing the argument we also highlight various methodological implications. First, conceptual development is a key aspect of the OIE, particularly when it is located within Dow's structured pluralism. As such elaboration on rule forms enhances the consistency of OIE as methodology. Second, the exploration of a taxonomic range of rules and of forms of fluidity can provide useful resources in mapping out institutional processes in real research.

The use of height data to measure living standards is now a well-established method in economics, and a number of core findings in the literature are widely agreed upon. There are still some populations, places, and times, however, for which anthropometric evidence remains thin. This paper introduces a new dataset from the Tennessee State Prison to track the heights of comparable black and white males born between 1820 and 1906. Shorter statures were associated with close proximity to the Mississippi River, and the largest share of the white–black stature gap was associated with nativity. Black and white statures declined throughout the 19th century, and farmers were taller than non-farmers.