S.7 Network models

Helpful prior learning and learning objectives

Helpful prior learning:


Learning objectives:

Have you ever wondered why some TikTok trends take over the internet while others disappear? A meme, dance challenge, or political message can suddenly be everywhere—shared and adapted by people worldwide. The short video describes a viral trend from 2010 called 'planking'.

But how does this happen? The key lies in social networks. Some people, like influencers, have thousands of followers, spreading ideas quickly. Others connect smaller groups, helping trends move from one community to another. Networks shape not just trends but also knowledge, cooperation, risks, and opportunities.

What is a network model?

A network model represents how parts of a system—people, organisations, or ideas—connect. In social network models, nodes (often circles) represent individual people or groups, and links show relationships—friendships, work ties, or shared beliefs. Figure 1 shows a friendship network. Notice that the lines linking people are unlabeled, as network diagrams typically represent the same relationship among nodes, in this case friendship.

Some networks are dense, with strong, frequent interactions. Others are loose, with weaker ties between groups. Bridging nodes—people who link different groups—play a crucial role in spreading knowledge, opportunities, and influence as well as making networks more resilient to disruption. In Figure 1, can you spot the people who connect friendship clusters?


Figure 2 shows another network model, where countries are nodes, and trade relationships link them. Like social networks, economic networks shape how resources, products and ideas spread.

Figure 1. Typical social network diagram where nodes, representing people, form dense relationship clusters. You can hover over the diagram to see the relationship clusters.

(Credit: Flourish)

An illustration of a network diagram showing primary trading partners in global trade.

Figure 2. Countries  connected to their primary trading partner, 2020.

(Credit: Visual Capitalist)

How do networks shape knowledge, cooperation, and influence?

Humans don’t just learn through direct experience. We share knowledge across generations and cultures through networks. Ancient trade routes spread technologies, scientists collaborate globally, and social movements like Fridays for Future (Figure 3) use networks to amplify their message.

Strong networks make cooperation easier. Shared beliefs, trust, and norms don’t emerge in isolation—they develop through interaction. A discovery in one place spreads, is refined, and then influences new communities.

But knowledge and influence don’t spread evenly. Some people are central hubs, reaching many other people directly. Others work at the edges of networks, connecting diverse groups and introducing new ideas. Both roles shape how movements and innovations grow.

A photograph of students protesting

Figure 3. The Fridays for Future student protests are an example of how networks contribute to shared ideas and movements for change.

(Credit: licensed from AdobeStock)

Connections, influence, and social tipping points

Imagine each person in your class is asked to choose two people to sit next to. A 1930s study did this with children and mapped their choices (Figure 4). Some students were chosen by many, forming central nodes (white, large). Others had fewer or no connections (blue).

This study shows how network centrality affects influence (Figure 5). Well-connected people—like influencers—spread ideas faster. But trust matters too. A recommendation from a friend carries more weight than one from a stranger.

An illustration of lines between students who indicated they wanted to sit next to one another

Figure 4. Who wants to sit next to whom in the classroom network? Lighter circles represent students most chosen by peers, dark blue circles represent those not chosen by anyone.

(Credit: Martin Grandjean, adapted from Jacob Moreno’s sociogram, CC BY-SA 4.0)

But centrality alone doesn’t explain how influence spreads. Network density, or how closely connected people are, also plays a role. In a high-density network (Figure 6a), where most people know and interact with each other, news and ideas move quickly. In contrast, in a low-density network (Figure 6b), where only a few connections exist between groups, information takes longer to spread and may not reach everyone.

Centrality and density are important, but some of the biggest changes to systems actually come from the edges. Small shifts in norms, if spread widely, can trigger social tipping points—moments when a new behaviour or belief spreads rapidly through society. For example, ideas about climate responsibility, once seen as fringe concerns, are now influencing business and government decisions worldwide.

Figure 5. Network structure with high centrality.

Figure 6. Two network structures, a) with high density and b) with low density

The strength of weak ties and the power of the periphery

Close friends (strong ties) provide support and trust. But weak ties—acquaintances or distant colleagues—bring new information and opportunities (Figure 7).

Social scientists found that people are more likely to find jobs through weak ties rather than close friends. Why? Strong ties mostly connect people who already know the same things, while weak ties bridge different groups, introducing fresh ideas.

The power of the periphery extends this idea. People at the edges of networks often drive innovation and change. Unlike those in the center, who reinforce existing structures, peripheral thinkers engage with diverse groups and experiment with new approaches.

Two network diagrams, one showing strong ties from a central point and a second one showing two clusters with bridging nodes.

Figure 7. Strong ties connect you deeply to a small group, but weak ties link you to new networks, expanding your access to information and opportunities.

Scientific breakthroughs often emerge from small research teams working at disciplinary margins. Many social movements start at the periphery, where marginalised voices introduce radical ideas that later shape mainstream thinking.

These shifts can lead to social tipping points—moments when a small but growing trend suddenly becomes unstoppable. A local regenerative business model, for example, may start as an experiment but, if widely adopted, can transform an industry.

Why is the structure of the relationships in networks important?

Network structure determines how fast information spreads, who holds power, and how resilient systems are to change.

Figure 9. Example of an organisation that is structured hierarchically. This hierarchy has three levels: a top level, a middle (management) level and a bottom level. 

Figure 10. An example of a modular network with three bridging nodes.

Why do network models matter for regenerative economies?

Network structures shape who has access to knowledge, resources, and decision-making. In today’s degenerative economic systems, wealth and influence concentrate in central hubs, leaving many disconnected from essential opportunities.

To transition to regenerative economies, we need strong, cooperative networks that distribute wealth, income, influence and opportunities more evenly to support resilience. Change moves through networks—starting in smaller clusters and gaining momentum as ideas spread. Bridging nodes—people and organizations connecting different communities—expand new economic models from local initiatives to global movements.

Some existing network structures already support regeneration:

Understanding how network structures and social tipping points interact helps us design economies that restore rather than exploit. By strengthening the bridges between communities, we can accelerate the spread of regenerative ideas and practices, ensuring they scale beyond isolated efforts to transform entire systems.

Activity S.7

Concept: Systems

Skills: Thinking skills (transfer and critical thinking)

Time: Varies, depending on option

Type: Individual, pairs or small groups

Option 1: Has your school reached a social tipping point on smartphones?

Time: 30 minutes, or longer if you invite a member of the school administration



Option 2: What’s the role of the fringe in social movements?

Time: 30 minutes

Read the following article about the controversy over the role and effectiveness of radical protest actions for social movements. The article has multiple links to more detailed explanations of various arguments and social movement theories, if you are interested.


Throwing soup at the problem: are radical climate protests helping or hurting the cause?


Option 3: Identifying the system model

Time: 20-25 minutes

Figure 11 is the circular flow of income model. It is often used to represent the economy, though it ignores critical information about the embeddedness of the economy in social and ecological systems (Section 1.1.2).

Illustration of the circular flow of income model

Figure 11. The circular flow of income, a commonly-used basic model of the economy

(Credit: Irconomics)

Option 4: Identifying the system model

Time: 40 minutes

The diagram in Figure 12 comes from the 2025 report from the World Economic Forum. The information about the risks was taken from surveys of business leaders. Here the colour and size of the nodes/parts have meaning, as do the thickness of the lines. The colours indicate different categories of risks: economic, environmental, social, geopolitical, and technological. Large nodes indicate a risk factor with an influence on many other risk factors. Thick lines indicate a strong relative relationship between the nodes.

Diagram of interconnected risks from WEF's Global Risks Report

Figure 12. The World Economic Forum’s 2025 Global Risks report model, showing the interconnected global risks.

(Credit: World Economic Forum, Global Risks Report 2025)

Checking for understanding

Further exploration

Sources

Cabrera, D., & Cabrera, L. (2018). Systems thinking made simple: New hope for solving wicked problems (2nd ed.). Odyssean Press.

Centola, D. (2021). Change: How to make big things happen. Little, Brown Spark.

Christian, D. (2018). Origin story: A big history of everything. Allen Lane.

Elsner, M., Atkinson, G., & Zahidi, S. (2025). Global risks report 2025. World Economic Forum. https://www.weforum.org/publications/global-risks-report-2025/digest/

Grandjean, M. (2015, March 16). Social network analysis and visualization: Moreno’s sociograms revisited. Martin Grandjean. https://www.martingrandjean.ch/social-network-analysis-visualization-morenos-sociograms-revisited

Granovetter, M. S. (1973). The strength of weak ties. American Journal of Sociology, 78(6), 1360-1380. https://doi.org/10.1086/225469

Harari, Y. N. (2015). Sapiens: A brief history of humankind. Harper Perennial.

Huang, C.-Y., Sun, C.-T., & Lin, H.-C. (2005). Influence of local information on social simulations in small-world network models. Journal of Artificial Societies and Social Simulation, 8(4). https://www.jasss.org/8/4/8.html

Sundell, A. (2022, February 11). Visualizing countries grouped by their largest trading partner (1960–2020). Visual Capitalist. https://www.visualcapitalist.com/cp/biggest-trade-partner-of-each-country-1960-2020/

Terminology (in order of appearance)

Coming soon!