Couples are less likely to physically collide with others than friends are Shutterstock/Shawn.ccf
Couples are less likely to physically bump into other people when walking in busy public spaces than pairs of acquaintances or work colleagues are. However, adding a child into the mix makes the group more likely to have a collision.
When developing mathematical models for how people move in crowds, researchers often borrow techniques from particle physics. But there is one particularly important way that two people in a crowded corridor can differ from a pair of particles – …
