Periodic Reporting for period 3 - EVORULES (The cultural evolution and ecology of institutions: An integrated evolutionary approach to the interrelated rules that regulate human social organization and cooperation) Reporting period: 2020-09-01 to 2022-02-28 Summary of the context and overall objectives of the project • What is the problem/issue being addressed?Humans live in groups of huge numbers of genetically unrelated individuals due to culturally-inherited social rules (“institutions”) that structure groups and provide solutions to coordination and collective action problems. Existing approaches to understanding cooperation coming from evolutionary biology have not appreciated the importance of institutions, while studies in the social sciences have not always appreciated the evolutionary processes involved in understanding the variation we see in institutions in the world today. This project aims to synthesize these different approaches in order to answer many fundamental questions about the evolution of institutions.• Why is it important for society?All human societies are structured by institutions, and they govern the way in which people are able to come together to cooperate to solve collective action problems. Only in certain places have societies developed more “inclusive” institutions (e.g. democratic governance, the rule of law) that enable the majority of the population (not just elites) to participate in economic and political activities. Similarly, in some cases societies have developed institutions that allow people to use natural resources in a sustainable manner, yet in others societies have succumbed to a “tragedy of the commons” which leads to over-exploitation and collapse. Therefore, understanding how effective institutions emerge, how they are shaped, and how they are spread underpins many of the most important challenges we face in the world today.• What are the overall objectives?This project will go beyond existing research by employing an overarching cultural evolutionary framework to address a number of important issues relating to the evolution of institutions. We are developing a modelling framework and computer simulations that will allow us to assess how and why institutions evolve, and what difference institutions make to solve cooperation problems in comparison to non-institutional processes. The project will assess these models and other theories by applying innovative statistical techniques to analyse cross-cultural, cross-national, and historical data on institutions and other relevant variables. This integrated approach taken in this project will hopefully create a step-change in our understanding of institutional change and how evolutionary and ecological processes have shaped the world we live in today. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far We have made good progress against the main research questions outlined in the original research proposal.We have assembled several datasets on institutional diversity across cultures and countries and supplemented these with new variables in order to test hypotheses about institutional evolution. We have examined the dynamics of evolution of complex societies using archaeological and historical information and shown how different aspects of societies evolve together across different societies, and that these packages of various roles, institutions, and technologies enable the coordination of large numbers of people to act in a politically unified manner. We also examined the rate of evolution of these traits and showed that changes in complexity seem to occur in bursts. I have also conducted comparative analyses testing how historical and geographical factors systematically affect the evolution of institutions. We have shown how ecological factors affected the evolution of state institutions in history, which has then shaped the evolution of modern-day country-level institutions and outcomes. Using these data we have also conducted preliminary analyses assessing the extent to which the similarity and diversity we see in countries around the world today has been shaped by deep cultural history. Employing cultural evolutionary theory I have developed different hypotheses about the evolution and spread of institutions underpinning large-scale societies and tested these ideas using spatially-explicit statistical models. These analyses indicate that in human history larger scale societies have tended to develop in regions of the world where 1) agriculture has been practiced for longer (giving societies more chance to develop new institutions), and 2) the degree of competition between groups has been stronger. We have also developed an initial agent-based modelling framework for developing different models of the evolution of cooperation. We are currently incorporating explicitly institutional processes into these models. Our initial analyses indicate that institutions can help groups solve collective action problems quicker, and make cooperation more stable.Working with collaborators in Japan we have assembled a new archaeological dataset on the spatial and historical distribution of large burial mounds in prehistorical Japan, which are an important indicator of the evolution of socially complex societies. This dataset will be used to assess some of the macro-scale models of the evolution of institutions for large-scale societies, and test hypotheses about the dynamics of institutional evolution. We will also be conducting field work in Kenya to examine the role of institutions in enabling collective action in community-based pastoralist conservancies. This work ties in to the socio-ecological modelling, and assessing hypotheses about the spread of institutions. We have been collating existing individual-level data and information on the institutions that different conservancies have developed. These data will be extended to include more conservancies and supplemented with ecological data. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) We have conducted several novel statistical analyses testing hypotheses about the evolution of institutions using newly-compiled cross-cultural and historical datasets. Some of these have been published already in international, peer-reviewed journals and have been well-cited. Others analyses are in the review process, or are being written up for publication.The approach we are taking in the agent-based modelling work is quite novel in seeking to develop a common framework in which different mechanisms of cooperation can be compared directly. In previous work most models have been developed separately so it is not always clear how different theories fit together and how some of the abstract mathematical models relate to the real-world causal mechanisms that many empirical researchers are interested in understanding. The approach we are taking will help clarify the similarities and difference between different proposed mechanisms and also highlight the difference that institutions make to explaining cooperation in human societies. As a team, the members of the project are preparing a paper that will be published in a special issue of a prestigious international journal, which will describe the approach we are taking in this project and summarize some of the developments to date. By the end of the project we will have conducted analyses at local, regional, to global scales using a variety of different techniques and sources of information. This will enable us to identify the important processes that shape institutional evolution at micro- and macro- scales and to see the connections between these different levels.