The Structural Microfoundations theory of the society is a work-in-progress model system backed by growing empirical evidence. 

We created this website to be theory's home.

You are my love. 

You are my sister. 

You are my friend. 

A trivial fact of our species’ social life is that the human social network edge type varies. This variation is not only important for each of these relationships, but also for the structure of the social network around us. This website introduces the models for what happens to the social network structure when the bulk of these relationships change. Our societies shift from kinship networks to friendship networks due to falling fertility, urbanisation, and migration. The second part collects an overview of the existing empirical evidence using large datasets, and suggests explicit empirical hypotheses. The final part covers how further phenomena are predicted by this theory, and ideas of how to test these.

With critical comments, collaborative ideas, or to receive updates on new results, please write to the email address: contact at microfoundations dot world.

Papers already out

NB. This is not the sequence of the papers in which they were published, but more the sequence it makes sense to read them now. Please note that the notation is evolving.

Modelling engine:

• Clustering Drives Cooperation on Reputation Networks, All Else Fixed

Fertility to network structure:

• Network Effects of Demographic Transition

Microfoundations logic rewires

• homophily in friendship:: Herding Friends in Similarity-Based Architecture of Social Networks

• kinship concept: Kinship Is a Network Tracking Social Technology, Not an Evolutionary Phenomenon (preprint)

• rise of ideologies: Fertility, Kinship, and Evolution of Mass Ideologies

• marriage traditions: Network Ecology of Marriage (preprint)

Papers on the variation of edge types in human social networks:

• Communication with family and friends across the life course

• In A Society of Strangers, Kin Is Still Key: Identified Family Relations in Large-Scale Mobile Phone Data (preprint) 

• Women Favour Dyadic Relationships, but Men Prefer Clubs: Cross-Cultural Evidence from Social Networking

• World-wide Evidence for Gender Difference in Sociality (preprint)

Social technologies

• Human Group Size Puzzle: Why It Is Odd That We Live in Large Societies

• Collaboration Conundrum: Synchrony-Cooperation Trade-off (preprint)

Engine room:

• Unbiased Library of k-regular, n-sized, Connected, Small Graphs (preprint)

With critical comments, collaborative ideas, or to receive updates on new results, please write to the email address: contact at microfoundations dot world.

COMING SOON: Theory building blocks [videos uploaded gradually]:

1. Prologue

Two stories of the human society

2. Brief version

Introduction to the theory. An illustrated table of contents.

3. Location in the knowledge web

Incitements and location in the knowledge web.

4. Recap: origins of cooperation

Essential recap of evolution of cooperation. The answer did not used to be trivial. Some building blocks are introduced.

5. Human has edge type

Human social relationships vary in type: kin, love, friend. This has structural consequences for the social network.

6. Graph structure matters for cooperation

The clustering coefficient is key to cooperation on human social network. This is a core point, the engine of theory.

7. Why we all gossip 

Brief natural history of third-party norm monitoring. 

8. Social network structure varies

Even when the degree is the same (everyone has the same number of friends), the interconnectedness of the social network graph can have a wide range.

9. How to build a kin network

Human kinship deconstructed into genetic and cultural, and then reconstructed into networks.

10. Fertility drives network structure 

The building blocks are put together. Falling fertility empties kin networks, giving way to friendship. 

Friendship comes with different network properties than kinship. This is why demographic transition results in differently structured social network.

Our social world changes.

11.  Urbanisation etc 

We expand the theory to other demographic process. Urbanisation has similar effects on network structure as falling fertility. 

Migration, deadly epidemics and war are added to the list. 

12. Quasi-kin solutions in ideologies and religions

Clubs, tribes, nations, territory, kin language cues.

13. Triangles in phone data

A clever trick in large phone dataset combined with brilliant sub-national statistics allowed the direct testing of the Microfoundations theory in one country, on big data.

14.  Network ecology of marriage

 Microfoundations mechanics to when and why humans create in-laws at the same time as choosing long-term romantic partners. A direct empirical test.

15. Network effects in mate choice

Indirect empirical test: a cross-cultural survey/experiment, in 7 languages three continents, suggests that network regulation through tracking in-laws might be a human universal. The main drivers are generation earlier fertility and current urbanisation, in line with the Microfoundations theory.

16. Wedding is a social technology

A wedding operationalises affinal kin bonds. Cultural pattern around the world is in support.

17. Homophily in friendship

Homophily increases the clustering coefficient in low-fertility, urban, migratory populations. In modern societies, we choose friends who are similar to us so that our social network becomes more integrated. The U transition is introduced. 

18. Birds of a feather

Friendship similarity data. This needs more work.

19. Kinship is a network trick

Reframing anthropology's kinship concept, predicting its emergence, key traits, and fall. 

20. Modern kinship 

Examples.

21. Small World effect

Demographic transition triggers the Small World Effect. Postal service, phone and email systems, and social networking sites merely make us see it rather than generate it.

22. Individualism is a coping strategy

The social network groups around us shape-shift from onion to overlapping clubs. Our group membership signalling becomes too taxing, so we better just be individuals: ‘Y'am who y'am’.

23. Trust, distrust, crime

Demographic transition decreases cooperative stance, and increases norm violations. Urbanisation, falling fertility, migration, wars, and epidemics all trigger social trust crises.

24. Law

Law is the society's adaptation to the increased increase norm violations due to urbanisation, falling fertility, etc. The altered payoff matrices remove the strategic element of collective action: strategic cooperation turns into mutualism. 

25. Modern economy is an infinitely-scalable social machine 

The network foundations to the forager, farmer, early urban, and modern urban economies. Today we organise ourselves into giant economic machines, that can last forever, and be of any size.

26. Optimal political systems

The ideal political system changes as our societies go through the U transition curve. Because of this, almost every society is out of sync with the optimal, is locked into a suboptimal constitutional system.

27. Fundamentalism

Value fundamentalism, ideological radicalisation, happens mid-transition through the U curve, and goes away by the end of the transition.

28. Fake news

Fake news is the side-effect of individuals' network management strategy, typical at the end of the U-transition. 

29. Inequality accelerator

The U transition makes the traditional inequality regulating institutions obsolete, and -- at the same time -- increases the network rewiring speed. Both result in increased social inequality. 

30. Psychological challenges

A new framing for teenage depression, urban and old age loneliness. Network mechanics explain the link between community living and longevity. 

31. Reputation industry

Cooperative reputation becomes a digitised social technology. Rating systems in airbnb, uber, etc, create scalable reputation, increases cooperativeness, and conjures up imaginary communities. Government-tracked social scoring emerges.

32. Engineered longevity

Some of us living longer will amplify the loneliness challenge. A space to invent new institutions.

33. How to wire 8bn people

Families have shrunk, we are all friends now. For the first time in human history, in fact, in the history of Life, it is possible for one species to design its own planetary social network. The slight hitch is that while the need for collective action is imminent, the human ape's social cognition capacity is limited to small groups, and this particular ape deeply dislikes steep inequality. Hmmm.

34. Summary

The aim is not to replace social sciences, but to create a layer under them. Microfoundations might allow the connection among social sciences with roots in biology.