Perhaps the most oustanding characteristic of humanity’s continuing experiment with large-scale collective living is the almost incredible social heterogeneity it seems to encourage. New York City, as one would readily find in the nation’s larger urban areas, contains within its boundaries numbers of well-defined ethnic or social enclaves, clusters of similar businesses, and areas so densely occupied that they appear to be endlessly submerged under a stream of humanity. The difference, the flavor of each of these is so striking as to be apparent to even the most casual observer. There are areas in Manhattan which are in themselves microcosms of what twentieth century America is, or could be. The Upper West Side of Manhattan, the setting of the study’s research, is one of these.