Coincidences often appear to us as remarkable, uncanny, or inexplicable moments—two people meeting unexpectedly in a faraway place, an idea recurring through unrelated channels, a chain of events that aligns just so. But when examined through the lens of network science, many such events can be seen not as pure chance, but as outcomes of underlying structures—patterns of connection and flow that shape the way we live, think, and meet.
Network science is the study of how elements—people, ideas, events, or systems—connect to each other. These elements, called nodes, are linked by edges that represent relationships or interactions. Though deceptively simple in form, networks can reveal how complexity arises from structure: how certain nodes become more influential, how clusters form, how information spreads, and how paths emerge between distant points. When applied to the question of coincidence, network science reframes the uncanny as something emergent, not accidental.
Small Worlds and Short Paths
One of the most widely known concepts in network science is the small-world phenomenon, popularised by Stanley Milgram’s experiment suggesting that any two people are connected by roughly six steps of acquaintance.[1] This principle underpins the idea that coincidences—especially those involving people—may be statistically probable in a highly connected world. The small-world network balances two features: clustering (tight-knit communities) and short global distances (just a few hops between any two clusters). It explains why a stranger in Tokyo might know your friend from university in Melbourne: not because the world is magical, but because it is structured to be traversable.
Weak Ties and Hidden Paths
Sociologist Mark Granovetter’s work on the strength of weak ties shows that it is often our acquaintances—not our close friends—who bring us new information, job opportunities, or unexpected introductions.[2] Strong ties provide emotional closeness but little novelty; weak ties bridge us to new clusters. Coincidences often emerge along these edges—not because the link is strong, but because the connection spans distance within the network.
These weak ties create invisible paths that suddenly light up in moments of coincidence. When two people from vastly different backgrounds discover a shared acquaintance or interest, they are not discovering a miracle—they are discovering the structure beneath their social surface.
Clustering, Bridges, and Crossroads
Networks are not flat. They form clusters—neighbourhoods of high connectivity—based on geography, profession, language, culture, or interest. But what makes a network dynamic and surprising are the bridges between clusters. These are often individuals who inhabit multiple worlds—engineers who dance flamenco, artists who serve on tech boards, migrants who speak three languages.
Coincidences often happen at these intersections, where people or ideas from different clusters converge. These are the crossroads of emergence, where serendipity has a higher likelihood not because of randomness, but because of structural opportunity.
Centrality and Exposure
In any network, some nodes are more central—meaning more connections flow through them. These nodes are not necessarily the most popular or powerful; rather, they may act as hubs or connectors between communities. Central nodes are more likely to be involved in events that appear coincidental, simply because they are statistically more exposed to encounters, ideas, or opportunities moving through the system.
This offers a gentle lesson: if you wish to increase your exposure to the unexpected, you may not need to wait for fate—you may only need to move closer to the centre of the web.
Network Science and the Logic of Coincidence
What network science makes clear is that many coincidences are not extraordinary at all—they are the visible surface of hidden architecture. A chance meeting, a phrase overheard in two different cities, a shared connection that closes a loop—all of these are reflections of how networks behave:
They contain shortcuts between distant nodes.
They feature weak ties that introduce novelty.
They exhibit clustering and bridging, allowing information and people to travel across domains.
They generate patterns that feel spontaneous but are shaped by structure.
Coincidence, in this sense, is often a matter of perspective: it is what happens when a pattern becomes briefly visible.
Practical Implications
If coincidence is a product of network structure, then it follows that we can design our lives to be more open to the favourable collisions that such structure makes possible. This doesn't mean engineering chance, but rather increasing the surface area for serendipity:
Cultivate and maintain weak ties—they are bridges to other worlds.
Place yourself at intersections of communities, disciplines, and cultures.
Be active in small-world environments—cities, festivals, networks of curiosity.
Share your interests and questions publicly—this invites others in the network to connect dots you haven’t seen.
Coincidence then becomes not a rare anomaly, but a signal that you are well-placed in the fabric of connection.
[1] Milgram, S. (1967). “The Small-World Problem.” Psychology Today, 1(1), 61–67.
[2] Granovetter, M. (1973). “The Strength of Weak Ties.” American Journal of Sociology, 78(6), 1360–1380.
Research credit: Developed with support from ChatGPT Deep Research by OpenAI.
Starting Friday, 1st August 2025, I’ll begin sharing a series of major coincidence stories—each paired with a full interpretation using the frameworks introduced in Part 1: Understanding Coincidence.
If you’d like to learn more about Coincidences, the writing project behind these stories, start with the Preface and About.