Final answer:
Clifford Shaw and Henry McKay from the University of Chicago discovered through Social Disorganization Theory that the high level of criminality in certain neighborhoods was due to socio-economic conditions and population instability rather than ethnic composition, emphasizing the importance of the social environment.
Step-by-step explanation:
Social Disorganization Theory and Crime
The individuals who found that certain neighborhoods maintained a high level of criminality over many decades despite changes in ethnic composition were researchers from the University of Chicago associated with the Chicago School. Clifford Shaw and Henry McKay were particularly influential in developing what is known as Social Disorganization Theory. This theory exposes the relationship between a neighborhood's socio-economic status, population stability, and crime rates, rather than ethnic composition alone. Shaw and McKay observed that certain neighborhoods harbored high crime rates across time, which could not be solely attributed to the ethnicity of the residents. Instead, they found that the social environment or cultural ecology of these areas, marked by poverty, ethnic heterogeneity, and rapid residential turnover, led to weak social ties and limited social control, fostering an environment conducive to crime.
Thus, it is not ethnicity itself that predicts crime rates but the nature of the neighborhood conditions. Stable, prosperous neighborhoods were seen to have lower delinquency rates, which contrasts with areas with high levels of poverty, residential mobility, and ethnic heterogeneity. The latter's conditions prevent the formation of a strong community social control, which is crucial in mitigating criminal behavior. Social Disorganization Theory has had wide-ranging implications and applications, including in law enforcement strategies such as the New York City Police Department's CompStat program.