Japan

Institutions of modern societies have often been argued to evolve, but their evolution is rarely examined in Darwinian and empirical terms. Here we use the categorical data set MaxRange on nations’ regime-types and their constituting institutions historically for analysis of their phylogeny. The MaxRange data set covers all nations in the world system of nations since 1600 with details on accountability structures, executive strength and degree of centralization, constitutional strength, democracy and other aspects of the political systems. We describe and analyze the character of the “true phylogeny” of regime-type evolution in the nations of the world 1600--2020. Our results indicate that evolutionary network rather evolutionary tree models have superior fit to data. Using the extracted phylogeny, we also investigate the dynamic networks of nations in terms of regime-types, accountability structures and their related background factors such as religions and language. Network centrality measures of nations and regime-types provide new important explanatory variables for network-adjusted survival analyses of various institutions, from types and levels of democracy to details of regime-types, including institutions like parliamentarism, presidentialism, and their hybrid forms.

Cultural Evolution Society 2021

An Evolutionary Political Science: How Modern Nations Evolved Institutionally

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AAAI 2026

We are pleased to announce the Fortieth AAAI Conference on Artificial Intelligence (AAAI-26), which will be held in Singapore EXPO from January 20 to January 27, 2026.

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### Conference Welcome

Welcome to the third Cultural Evolution Society Conference, CES2021. In the conference, which will be held from June 9-11, 2021, about 180 researchers from East Asia, Oceania, Middle East, Europe, North and South America give presentations on their latest research advancing the evolutionary understanding of human and nonhuman animal culture.

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[![](https://assets.underline.io/uploads/markdown_image/1/image/1ef06ffd05f80957b4a5b685f63ee3ba.png)](https://www.chain.hokudai.ac.jp/CES2020/wp-content/uploads/2021/06/fullprogram.pdf)
[![](https://assets.underline.io/uploads/markdown_image/1/image/12285eb22580949635121d15d5b46325.png)](https://www.chain.hokudai.ac.jp/CES2020/wp-content/uploads/2021/06/abstracts.pdf)

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**Scientific Committee:** [Kenichi Aoki (Meiji University)](https://sites.google.com/site/kenichi1aoki/home), [Yasuo Ihara (the University of Tokyo)](https://researchmap.jp/read0209180?lang=en), [Hiromi Matsumae (Tokai University)](https://sites.google.com/site/hiromimatsumae/eng), [Naoko Matsumoto (Okayama University)](https://researchmap.jp/nmatsumoto_okayama-u), [Masako Myowa (Kyoto University)](https://myowa.educ.kyoto-u.ac.jp/en), [Hisashi Nakao (Nanzan University)](https://www.hisashinakao.com/), [Patrick E. Savage (Keio University)](https://sites.google.com/view/comp-music-lab/home)

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The demographic transition - how and why most populations are having fewer offspring despite resources increasing - remains a mystery. A shift from vertical transmission (learning from parents) to horizontal transmission (learning from peers) is deemed instrumental in the quick spread of low fertility values, but we lack an explanation for how such a shift occurs. Women’s personal advice networks are places where ideas about fertility practices are exchanged, therefore investigating ego networks is key to understanding this change. We expect that the expansion of markets and education into rural areas leads to shifts away from valuing kin relationships towards valuing non-kin, and from kin dominated networks to non-kin networks. We expect ego characteristics to influence these friendship dynamics. Here, using comprehensive demographic and relational data from 22 communities in rural Poland, we investigated how the characteristics of women’s personal networks change with ego-level and community-level attributes, and how network characteristics affect cultural transmission. We focused on structural features of networks, frequencies and intensities of interaction and bi-lateral social support, and closeness and emotional support. We found that women characterized by market integrated values (i.e. high education, non-farming occupation, status) have less kin and more unrelated friends in their networks, who they rely on for emotional support. Women characterized by traditional rural values rely on genetic kin and affines, for practical and financial support. These networks of different compositions, characterized by different inter-personal relationships, moderate information transmission and help explain the spread of low fertility values.

Female friendship and the horizontal transmission of low fertility values

In the demographic transition, “modernizing” populations willingly choose to have fewer children, causing an otherwise unpredicted steadying and even decline of population. This is on ongoing source of confusion for evolutionary modellers. 
Part of what shapes reproductive behaviour are socially learned choices about how many children to have. Recent work used analytic and agent based models to compare socially learned reproductive strategies that traded off between chosen birth rate and strength of horizontal transmission of that choice (Wodarz et al 2020). It was claimed that reduced mortality favours those strategies that invested in higher horizontal transmission, even at the cost of lower birth rates. This dynamic was claimed as a possible explanation of the demographic transition. However, tacitly baked into the structure of these models was an increase in infant mortality which drove the results, invalidating the claims about the demographic transition, characterized by significantly reduced infant mortality. Using both analytic and agent based models explicitly accounting for infant mortality and adult mortality, I demonstrate that decreasing infant mortality favors the cultural transmission of high birth rate reproductive strategies, while decreased adult mortality favors high horizontal transmission strategies. As decreased infant mortality is a hallmark of the initial phase of the demographic transition, this would amplify the already expected population explosion caused by decreased infant mortality. It is, however, actually a dynamic that would have to be countered to produce the demographic transition. Other social learning dynamics are proposed that could explain the demographic transition.

Reproductive behavior and social transmission of reproductive behavior in changing contexts: modelling the dynamics of trade offs in relation to the demographic transition.

Based on Life History (LH) Theory exposure to environmental unpredictability/harshness is expected to promote a fast LH strategy, shorted time horizon and high levels of risk behavior. Studies testing these predictions mainly evaluated adult samples. We evaluated the predictive power of family unpredictability, harshness and demographic characteristics of low SES Brazilian young adolescents on reproductive milestones, future horizon and risk behavior. Participants (n = 203 M = 12,7 years old) answered to the scales Family Unpredictability during Childhood and Unpredictability Beliefs, questions about the expected age to attain reproductive milestones, time horizon, life expectation, risk behavior and demographics. Results indicated that different dimensions of unpredictability significantly predicted risk behavior, expected age of first sexual intercourse and child, subjective life expectation and future horizon. Demographic characteristics (e.g. mother's age at childbirth) enhanced predictive power in some models. Harshness did not predict any of the criterion variables. Overall, our findings support LH Theory predictions about the role of unpredictability in promoting fast LH strategy, shortened life horizon and risk and demonstrate that the relations among these variables are established and can be accessed from early adolescence. Social and theoretical implications of these findings are discussed.

Can environmental unpredictability predict life history strategy of young Brazilian adolescents?

In this abstract, by focusing on the functions of the hippocampus and basal ganglia of human brain, we propose that the highly conserved functions of subcortical structures contribute to establish our ‘linguistic niche’ in the process of human evolution. To be more specific, the hippocampus is assumed to store information of when, where and what with multisensory input (Tsao et al., 2018). On the other hand, the basal ganglia are the neural basis for general functions in both motor and language domains (Shi & Zhang, 2020). The coordination of these brain areas (Szczepanski & Saalmann, 2013) provides the neural basis of lexical conception and syntactic operation leading to displacement, which is one of the design features of language enabling humans to talk about things and situations outside from here and now (Hockett, 1960). As a result, in the situation when a group of humans were hunting, and one member discovered a dead deinotherium, in order to exploit it, he must exchange information with other members to persuade them to cooperate. Such cooperation as a high-end scavenging made human ancestors distinguished from bone-crunching garhi and habilis. This information exchange requires the feature of displacement of language, supported by the functions of the hippocampus and basal ganglia (Zhang & Shi, in press). 

Selected References 

Shi, E. R. & Zhang, Q. (2020). A domain-general perspective on the role of the basal ganglia in language and music: Benefits of music therapy for the treatment of aphasia. Brain and Language, (206) 104811. Doi: 10.1016/j.bandl.2020.104811.
Szczepanski, S. M., & Saalmann, Y. B. (2013). Human fronto-parietal and parieto-hippocampal pathways represent behavioral priorities in multiple spatial reference frames. Bioarchitecture, 3(5), 147-152.
Tsao, A., Sugar, J., Lu, L., Wang, C., Knierim, J. J., Moser, M. B., & Moser, E. I. (2018). Integrating time from experience in the lateral entorhinal cortex. Nature, 561(7721), 57-62.

Displacement and Linguistic Niche

In a laboratory experiment with human participants, we investigated the evolution of category systems in terms of their optimality and complexity over time. We contrast two evolutionary scenarios: one where category systems are passed between individuals in a serial transmission chain and another where the systems are developed within single learners. Crucially, in both cases we control for the evolutionary age of the category systems, allowing systems developed by individual learners to be iterated the same number of times as those developed among several learners (see for discussion Miton & Charbonneau, 2018). We find that both evolutionary regimes discover a similar number of unique category systems, but individual learning discovers and maintains more complex systems than cultural transmission does. Cultural transmission, on the other hand, discovers simpler systems that are optimized to be easily learnable, and therefore transmitted among different individuals with high fidelity. This result runs opposite to our field's received notion that artifact complexity is a hallmark of cumulative cultural evolution (e.g. Boyd & Richerson, 1996). There are deep mathematical similarities between evolution and learning (Suchow et al, 2017) that allow us to analyze individual learning and cultural evolution within one framework and refine our understanding of the diagnostic differences between the two.

The cumulative cultural evolution of category systems: when individual learning creates more complex artifacts

Objective: It has been argued that teaching promotes the accurate transmission of cultural traits and eventually leads to cumulative cultural evolution. However, several previous studies have provided a disclaim to the argument. In the current study, we constructed a computational model of social learning under teaching to demonstrate that teaching plays a causal role in the emergence of cumulative cultural evolution. We also examined the conditions teaching promotes cumulative cultural evolution.

Methods: Processes of acquiring complex technologies were modeled as a search problem in a complex random network with multiple goals. The reinforcement learning agents searched for better goals and taught their experiences to agents in the next generation. In the simulation, we implemented a trade-off between individual learning (an opportunity for innovation) and teaching (the processes of faithful transmission): long periods of teaching are required for accurate transmission of advanced technologies. However, the more extended time society invests in teaching, the less time is left for innovating advanced technologies by the younger generation.

Results: Agent-based simulations revealed that the task difficulty moderates the positive influences of teaching on the cumulative cultural evolution: when the task was too difficult and advanced technologies could not be acquired by individual learning within a lifetime, spending a longer time on teaching, even at the expense of time for innovation, contributed to cumulative cultural evolution. On the contrary, the easier the task, the more time spent on innovation instead of teaching contributed to improving performance.

Conditions under which long-term teaching contributes to the cumulative cultural evolution of technology

Cultural attractor landscapes describe the time-evolution of cultural variants (i.e. behaviors, artifacts) over successive transmission events. When cultural variants sit at a local minimum of a stable attractor landscape, there will be no cumulative error over transmissions, allowing Darwinian selectionist dynamics to drive cumulative cultural evolution. But because cultural attractors are the emergent products of shifting populations (individuals can leave or die, and new individuals can be born or enter the population) of individuals with potentially-idiosyncratic and dynamic cognitive landscapes, which are in turn the emergent products of individual experience within a culture, stable cultural attractor landscapes cannot be taken for granted. Little is known about how cultural attractors form or stabilize in light of this culture-cognition feedback loop. We present a model of cultural attractor dynamics, which adapts a cognitive model of unsupervised learning of phoneme categories in individual learners to a multi-agent setting wherein individual learners are tasked with categorizing and generating signals for one another. Beginning from a state in which all agents possess a set of randomly distributed categories of uniform probability, under some conditions populations self-organize into signal clusters, which constitute an identifiable cultural attractor landscape. We explore the role of various innate cognitive biases, levels of transmission error, learning periods, lifespans, population sizes, and network structures to understand when population-level structure may emerge, what properties it is likely to have, and how stable it is. Our analyses can provide insights into the conditions that may be favorable or unfavorable for cumulative culture to emerge.

The Emergence of Cultural Attractors: How Dynamic Populations of Learners Achieve Collective Cognitive Alignment

Achieving sustainability is as much about knowing what defines sustainability as it is about doing the right thing. Without complete information about global stock levels, ecological tipping points, resource dynamics, societal metabolism, enforcement costs, etc., an enlightened citizen or social planner cannot define the strategy space that constitutes sustainable action. We break from traditional modelling approaches, which assume the conditions for sustainability are known. Using an agent-based model, we investigate the evolution knowledge about the sustainable courses of action in a common-pool resource dilemma. Our models show that the structure of the resource, that is, the set of parameter governing it, in conjunction with sufficient inter-group variation in cultural beliefs, is critical to the evolution of sustainability. Specifically, sustainability can evolve if the resource maximizes the difference between sustainable cooperative outcomes and non-cooperative unsustainable outcomes. Nevertheless, we find that this equilibrium is seldom found before an initial collapse.

Resource Characteristics and the Evolution of Sustainability

The patriarchal system is hegemonic in the contemporary world. In this study we aimed at understanding the causes of this prevalence, investigating the evolutionary origins of patriarchy. Our question was whether the masculine philopatry is related to the maintenance of the patriarchal structure. We conducted an integrative bibliographic review of the ethological literature, emphasizing the development of feminist concepts about patriarchy and the parental preferences on species evolutionarily close to humans. In addition, we analysed matrilineal communities such as Minangkabau, located at Indonesia, Asia; Mosuo, at China, Asia; and Umoja, at Quenia, Africa; and also two Brazilian social groups with traces of matriarchy, denominated Noiva do Cordeiro and Quebradeiras de Coco, for current alternatives that have dissociated from the prevailing patriarchy. In particular, Umoja and Noiva do Cordeiro were created in response to the preponderant sexism and violence suffered by its founders and other women, who came together to remodel their future actively. The ethological analysis allowed understanding the emergence of patriarchy, showing some socio-cultural contexts, such as sedentarism, language and parental preference, in certain cultures, as promoting its formation. Throughout this research, it was also noticeable that the number of scientific and academic studies on non-patriarchal societies, mainly in the scope of ethology, is quite little. Overall, the present study reveals a contrast between the patriarchy and distinct contemporary social configurations which have detached from feminine subordination, evincing that it is possible for our social systems to change and that we can carry out such transformation, as we understand and reflect about these processes.

Patriarchal hegemony from an ethological perspective and other social systems

Evolutionary theory supports the development of scientific explanations of the biological, behavioral, cognitive, and cultural diversity found around the world. Despite the wide ranging interdisciplinary nature of evolution science, evolution education in the general education context remains almost exclusively within the domain of the biology classroom. To engage this challenge and opportunity in a systematic fashion, the OpenEvo project has emerged as a Networked Improvement Community for evolving an open, networked, and interdisciplinary evolution education research community. The network is organized around principles of sociocratic governance, and focused on creating the conditions for innovations in interdisciplinary evolution education to emerge and thrive. The Concepts & Theory Circle has begun a critical analysis of the internationally recognized Understanding Evolution Conceptual Framework for guiding evolution teaching across K-16 (general education and undergraduate) contexts. The Research Circle is working to develop novel assessment tools for measuring conceptual learning about evolution as an interdisciplinary science, and the supports needed to engage in empirical research on the proposed revisions to the Understanding Evolution Conceptual Framework. The Teacher Education Circle is working to develop open syllabi for model teacher education courses and professional development programs to support teaching evolution as an interdisciplinary science. We will highlight the challenges and opportunities presented by this work, describe the current state of core projects within the network, and discuss the potential for teaching cultural evolution science to emerge as an essential educational innovation needed to foster an understanding of our changing world adequate to the challenges of the moment.

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