Shaw and McKay's statistical methodology in Juvenile Delinquency and Urban Areas
can be read as a response to the methods and conclusions of constitutional theories.

        In their Juvenile Delinquency and Urban Areas (1942), Shaw & McKay applied the Concentric Zone Model developed by Park & Burgess to the study of juvenile delinquency. They examined arrest rates of juveniles throughout the city of Chicago during the years 1900-06, 1917-23, and 1927-33. These were years of high immigration, meaning that immigrant groups rapidly "migrated" from the inner city towards the suburbs, as the older and more established immigrant groups were pushed along by the arrival of poorer immigrant groups, who took their place in the center of the city. By comparing the rates from three different time periods, Shaw & McKay believed they could show whether delinquency was caused by particular immigrant groups or by the environment in which immigrants lived. That is:

• if high delinquency rates for particular immigrant groups remained high during their migration through the city’s different ecological environments, then delinquency could be associated with their distinctive constitutional or cultural features;
   
• if delinquency rates decreased as immigrants moved through different ecological environments, then delinquency could not be associated with the particular constitution of the immigrants, but must somehow be connected with their environment.

        Dividing three maps of Chicago into even grids, Shaw & McKay shaded each square darker or lighter to indicate its average arrest rate over the three time periods:

Comparing the maps, Shaw & McKay recognized that the pattern of delinquency rates not only remained constant over time, but also corresponded to the "natural urban areas" of Park & Burgess’ Concentric Zone Model. They came to the important conclusion that delinquency rates always remained high for a certain region of the city (ecological zone 2), no matter what immigrant group lived there. Therefore, delinquency was not "constitutional"—as Lombroso and his followers had argued —but must somehow be correlated with the particular ecological environment in which it occurs!  Shaw & McKay’s eventual explanation of this correlation is their "social disorganization theory."

For more information, see. . .
 

Shaw, Clifford R. The Jack Roller: A Delinquent Boy’s Own Story. Chicago: University of Chicago Press, 1930.

——————. The Natural History of a Delinquency Career. Chicago: University of Chicago Press, 1931.

Shaw, Clifford R. & Henry D. McKay. Juvenile Delinquency in Urban Areas. Chicago: University of Chicago Press, 1942.

Shaw, Clifford R., Henry D. McKay & James F. MacDonald. Brothers in Crime. Chicago: University of Chicago Press, 1938.
 

. . .or Other Works of the Later Chicago School