Neighborhoods.

We grow up in boxes, go to school in boxes, and move around in boxes from box to box to hang with people we don't really know or trust because it's economically expedient. We know people because we work with them or have a shared interest.

It used to be different. People are wired for community. We are meant to live and work with people we know and trust forever.

Modern architecture and urban design support efficient movement between strangers, which is unhealthy because it isolates us. Housing and workplaces should be smaller and optimized for smaller groups of people who can trust each other because they naturally run into each other.