How Expanding Social Circles in the Smartphone Era Are Deepening Global Polarization

In today’s hyperconnected age, people have more friends, followers, and digital acquaintances than at any other point in history. Yet paradoxically, societies around the world are showing signs of deepening division. According to new research from the Complexity Science Hub Vienna, the expansion of our close social circles—from an average of two to roughly five friends between 2008 and 2010—may be a key driver of this growing polarization. The study suggests that the very networks meant to bring us closer are, in subtle ways, pushing us apart.

The Study Linking Friendship Networks to Polarization

Researchers at the Complexity Science Hub Vienna, led by Stefan Thurner, examined social network data from the late 2000s—a period marked by the explosive rise of smartphones and the early dominance of platforms like Facebook and Twitter. They discovered a striking trend: as people’s friend networks grew, ideological tolerance declined. Larger social circles seemed to make it easier for individuals to withdraw from uncomfortable conversations, forming clusters of like-minded peers.

In smaller circles, friendship often required compromise and patience. But as social networks expanded, people could afford to disengage from those who challenged their views. The study identifies this as a measurable contributor to modern polarization, showing how the density of a social network can reduce exposure to differing perspectives.

The Smartphone Era and the Social Expansion Effect

Between 2008 and 2010, smartphones transformed how we interacted. Platforms like Facebook, Twitter, and later Instagram created environments where maintaining dozens—or even hundreds—of connections became effortless. This newfound accessibility didn’t lead to a greater exchange of ideas, however. Instead, it encouraged algorithmic sorting and self-selection.

The “social expansion effect” describes how broad networks can produce more homogenous clusters. As individuals expand their friend groups, they also amplify selective engagement—choosing whom to interact with and whom to ignore. The result is a digital landscape filled with echo chambers, where the illusion of diversity masks the reality of narrow ideological exposure.

Why More Friends Can Mean Less Tolerance

The study’s findings are rooted in social psychology. As people’s social circles grow, each individual relationship holds less emotional weight. When disagreements arise, it becomes easier to detach rather than resolve conflict. This behavioral pattern, which the researchers describe as “tolerance erosion,” weakens the interpersonal skills that once held communities together.

Network theory supports this phenomenon. Humans can only maintain a limited number of meaningful relationships—often referred to as “Dunbar’s number,” typically around 150. When technology stretches that number artificially, it can create cognitive overload and social fatigue. In that context, maintaining harmony by avoiding disagreement becomes the default. In a world of countless voices, walking away from the one that challenges us feels simpler than engaging.

Democracy’s Dependence on Small-Circle Communication

The implications extend beyond personal relationships. Democratic societies rely on civil discourse—a willingness to engage across ideological lines. Historically, smaller communities and intimate friend groups forced individuals to navigate differing opinions. But as polarization grows and tolerance diminishes, that foundation of coexistence begins to erode.

The Complexity Science Hub Vienna study echoes warnings from organizations like the Pew Research Center and MIT Media Lab: polarization is not merely cultural but structural. The design of modern communication networks fosters separation. When social circles become echo chambers, democratic cohesion weakens. Public dialogue becomes more adversarial, and consensus more elusive.

Can We Rebuild Tolerance in a Networked World?

If larger networks breed fragmentation, the path forward may lie in depth rather than breadth. Building fewer, more meaningful connections can counteract the isolating tendencies of modern platforms. Digital empathy—actively engaging with differing opinions online—can also help restore balance.

Some technology companies and civic initiatives are exploring solutions. Algorithmic transparency, for example, aims to reduce the invisibility of bias in online feeds. Educational programs focused on media literacy and dialogue training can strengthen tolerance across generations. Restoring social cohesion in a networked world requires not fewer connections, but more intentional ones.