A dormitory. Miniature from a manuscript in French of the "Decameron" by Giovanni Boccaccio (1313-1375), Italian writer, illuminated by the Master of Mansel. 1450 . Arsenal Library, Paris, France (Photo by Leemage/Corbis via Getty Images)

The Hot New Millennial Housing Trend Is a Repeat of the Middle Ages

For most of human history, people were hunter-gatherers. They lived in large camps, depending on one another for food, childcare, and everything else—all without walls, doors, or picket fences. In comparison, the number of people living in most households in today’s developed countries is quite small. According to the Census Bureau, fewer than three people lived in the average American household in …