The way we bump into each other in a crowd isn't about being polite or social—it’s actually just following simple, random rules of physics.
April 2, 2026
Original Paper
Simple spatial processes can generate heterogeneous contact distributions in face-to-face interactions
arXiv · 2604.00652
The Takeaway
We often assume the frequency of our face-to-face meetings depends on who we like or know. This study shows that just the physical way people move through space—following simple targeting and mixing rules—naturally creates the same complex social networks seen in real-world data.
From the abstract
Face-to-face interactions reveal recurring patterns, suggesting the possibility of shared underlying mechanisms. More specifically, inter-contact durations, contact durations and number of contacts per edge share similar heavy-tail distributions in many empirical settings. A common intuition is that face-to-face interactions may be influenced by spatial constraints, and that the observed complex behaviors could arise from such physical limitations. Our models explore the impact of this constrain