The association between county-level IQ and county-level crime rates

An impressive body of research has revealed that individual-level IQ scores are negatively associated with criminal and delinquent involvement. Recently, this line of research has been extended to show that state-level IQ scores are associated with state-level crime rates. The current study uses this literature as a springboard to examine the potential association between county-level IQ and county-level crime rates. Analysis of data drawn from the National Longitudinal Study of Adolescent Health revealed statistically significant and negative associations between county-level IQ and the property crime rate, the burglary rate, the larceny rate, the motor vehicle theft rate, the violent crime rate, the robbery rate, and the aggravated assault rate. Additional analyses revealed that these associations were not confounded by a measure of concentrated disadvantage that captures the effects of race, poverty, and other social disadvantages of the county. We discuss the implications of the results and note the limitations of the study.