Paoli, Pennsylvania, is a small town with a local suburban hospital. Patients at Paoli Memorial recover in a row of rooms facing a small courtyard. In the early 1980s, a researcher visited the hospital and gathered information about patients who had undergone gallbladder surgery between 1972 and 1981. Gallbladder surgery is routine and generally uncomplicated, but most patients in the 1970s recovered for a week or two before they returned home. Some took longer to recover than others, and the researcher wondered whether subtle differences between the hospital rooms might explain this discrepancy. Some of the rooms on one side of the hospital faced onto a brick wall, whereas others slightly farther down the corridor faced onto a small stand of deciduous trees. Apart from their differing views, the rooms were identical... Read the full article here.