What 13 Million Reddit Connections Can Teach Us About Serendipity and Growth

A 2022 study I wish I’d found sooner shows how the diversity and depth of our networks - not their size - shape prosperity and innovation.

Every so often, you stumble on a piece of research that makes you think, “I wish I’d found this sooner.”

For me, that moment came recently when I discovered a 2022 paper by Luca Maria Aiello, Sagar Joglekar, and Daniele Quercia in Scientific Reports. It’s one of those rare studies that doesn’t just confirm a long-held intuition - it measures it.

What made me smile was discovering that I even share several connections with the authors - a reminder that we all live inside the very networks we study.

Their work analysed more than 13 million connections between people on Reddit, across all fifty US states, to see how patterns of social interaction related to regional economic development. What they found was both elegant and profound. It wasn’t the number of connections that mattered most, nor how frequently people interacted. Instead, it was the diversity and quality of those ties - what they call multidimensional tie strength - that best predicted prosperity.

In regions where online relationships combined strong local support with broad, knowledge-sharing bridges to other communities, economic performance was markedly higher. Where ties were either too inward-looking or too diffuse, the opposite was true.

At one level, this might seem obvious: we all benefit from being part of a supportive local network while also having access to new ideas from further afield. Yet this study gives that intuition mathematical weight. The researchers modelled ten psychological dimensions of relationships - from trust and emotional closeness to information exchange - and found that when considered together, they explained twice as much of the variation in economic outcomes as simple measures of contact frequency. In other words, relationships are not one-dimensional pipes; they are rich, layered systems through which knowledge, confidence, and opportunity circulate.

I wish I’d known about this when writing Serendipity: It Doesn’t Happen by Accident, because it provides striking empirical support for one of the book’s central arguments: that innovation and progress depend on networks that blend difference and trust - what I’ve called “structured serendipity.” Serendipity doesn’t emerge from chaos alone, nor from rigid hierarchy. It thrives at the boundary between the two - what Stuart Kauffman described as the edge of chaos - where ideas can collide, combine, and evolve within a framework that still holds them together.

Aiello and his colleagues’ findings illustrate this perfectly. The regions that prosper most are those that manage to be locally cohesive but globally connected. They are the social equivalent of Building 20 at MIT, where physicists, linguists, and radar engineers collided in corridors and invented entire disciplines. They are what Birmingham’s Lunar Society achieved in the eighteenth century - an ecosystem of close collaboration and wide curiosity. And they are what I’ve seen time and again in the Cambridge cluster: networks that are open enough to let new ideas in, but grounded enough to turn them into reality.

What makes this study particularly interesting is its method. By analysing the language of millions of online exchanges, the authors were able to infer how relationships functioned - who provided support, who shared information, who bridged between groups. This kind of data-driven sociology would have been impossible even a decade ago. It suggests we are getting closer to being able to measure something that has always seemed elusive: the conditions that make serendipity possible.

Of course, one should be cautious. Reddit users are not a perfect mirror of society, and correlation is not causation. But the principle stands. Prosperity and innovation depend not just on how connected we are, but on the balance of our connections. Too much bonding without bridging leads to stagnation; too much bridging without trust leads to fragility.

That balance - between strength and openness, between the familiar and the surprising - is what I believe defines truly innovative societies and organisations. It’s why the best ideas rarely emerge from committees or command structures, but from networks of motivated people who bump into each other, share knowledge, and build on one another’s insights.

So while I regret not spotting this paper sooner, I’m also pleased. There’s something rather fitting about discovering it by chance. After all, it’s a small act of serendipity in itself - one that reinforces exactly what the research describes: the power of unexpected connections to change how we see the world.

It’s also a reminder that serendipity doesn’t end when a book is published. It continues through the new ideas, data, and connections that find us afterwards - often when we least expect them.

Reference: Aiello, L. M., Joglekar, S., & Quercia, D. (2022). Multidimensional tie strength and economic development.Scientific Reports, 12(1), 11819. https://doi.org/10.1038/s41598-022-15758-7