IQ and delinquency: A direct test of the differential detection hypothesis.

A number of studies have reported that juvenile delinquency is negatively related to IQ scores. The IQ/delinquency relation has been questioned on the basis of the differential detection confound, which attributes the apparent relaton to biased likelihood of detection, and thus inclusion in research, of low-IQ delinquents. A direct test of the differential detection hypothesis was conducted by comparing the mean IQ scores of two groups of delinquent subjects from the same birth cohort. Group 1 had been detected in delinquent acts by police. Group 2 was not known to police, but was equivalent to Group 1 on amount and seriousness of self-reported delinquency. The two groups did not differ significantly on IQ, but both groups scored significantly below nondelinquent cohort members. Results were inconsistent with the prediction of group differences posed by the differential detection hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)