In the early 1940s, sociologists Clifford Shaw and Henry McKay conducted research on criminal behaviour in the city of Chicago. What came out of their work became known as “Social Disorganisation Theory” (SDT), and the school known as the “Chicago school” (not to be confused with the “Chicago school” of economics).
The overarching thesis to the SDT is that criminals, specifically juvenile delinquents, are not abnormal people. They are not “deviant” relative to their environment. In fact, they are quite rational, responding normally and rationally to an abnormal and irrational social environment. Therefore, the Chicago school of criminology is based around analysing the environment of certain types of juvenile criminals, according to the Center for Spatially Integrated Social Science.
The basic findings of Shaw and McKay were based entirely on the idea of social ecology: people act within an environment that shapes them as well as being shaped by them. This means, in their findings, that criminality is based around a specific neighbourhood, regardless of who might live there at any specific time. Once criminality becomes part of the culture of the area, it becomes a tradition that gets handed down from generation to generation. Hence, it is the place, not the people, who matter.
According to Shaw and McKay, the basic cause of criminality is the lack of a specific area or neighbourhood, to either create or accept a set of common values that would integrate the social whole. The basic causes of this main cause are equally simple. Areas that cannot articulate common values are areas that have a high level of residential instability, have a light level of heterogeneity in language, race and/or ethnicity, and are poor. Diversity is a great evil in this approach to crime, since it prevents the creation of a unified region. Rapid industrialisation and change is sometimes considered another cause.
Researchers who accept the basic thesis of SDT must focus on the history of the area they are studying. They must analyse the social and ethnic nature of the area's history. Integration of different ethnic groups and races is generally a bad thing, since it does not create neighbourhoods but enclaves. According to Austin Peay, enclaves do not create a common culture, but might in fact become productive of general crime.
Ethnicity is not a factor in crime, but a mixture of ethnic groups is. Poverty is not a cause of crime, but it has trouble dealing with crime due to a lack of resources available to combat it. Common neighbourhood values are essential in controlling crime as is basic ethnic, cultural and linguistic unity. But once an area suffers from the basic causal elements of crime, there is no going back. The area becomes contaminated with a defective culture that creates defective children. They are defective in that they respond rationally to an irrational society, which itself, makes them irrational.