To help his staff of young architects understand the needs of those for whom they design housing, David Dillard sends them on “sleepovers.” They put on pajamas and spend 24 hours in a senior living center in the same conditions as people in their 80s and 90s. They wear earplugs to simulate hearing loss, tape their fingers together to limit manual dexterity, and exchange eyeglasses to replicate vision problems. Dillard says, “The biggest benefit is [that] when I send 27-year-olds out, they come back with a heart 10 times as big. They meet people and understand their plights” (Rodney Brooks,…