The world is entering a new era of cognitive science that allows us to understand human behavior better than ever before. In fact, the Organization for Economic Co-Operation and Development recently labelled the 21st century the “Age of Biology,” noting the growing impacts of the ongoing life-science revolution, which the group predicts will change economies, create new technologies, and broadly reshape our lives.For planning, this new age means we can record how people see and feel about their surroundings, not as machines, but as animals keen on connection and ruled by anxieties. Imagine being able to collect real-world, real-time data about emotional habits in the built environment and to definitively answer perennial questions such as why people enjoy walking through miles of a dense urban settings like Manhattan but consistently shun barren landscapes like Boston’s infamously empty City Hall Plaza.Today it’s possible. With affordable new tools, we can track subconscious predispositions and use metrics to explain the human response to an existing development or predict responses to a new development. Planning will become trackable and quantifiable in ways unimaginable in the 20th century.