Commercial high-rises may pack cities with people, but most towers are largely antisocial. Empty lobbies blank out street life, and elevators silence and isolate individuals. Thick concrete service cores relegate occupants to the perimeter, keeping people on one side of the building from people on the other. Floors stacked like pancakes stop communication between levels. Divided, striated, and contained, high-rises squeeze out the great architectural subject of modern architecture—space—eliminating the medium of social connectivity.