More barriers exist now than at the end of World War II, says designer Alexandra Auer. And when you erect one wall, you unwittingly create a second -- an "us" versus "them" partition in the mind that compromises our collective safety. With intriguing results from her social design project focused on two elementary schools separated by a fence, Auer encourages us to dismantle our biases and regain perspective on all the things we have in common.