Monday, September 13, 2010

Paradoxical finding on juvenile sex offender risk

Leading tools cannot distinguish among delinquent boys

New tools designed to predict sex offender recidivism risk among juveniles continue to generate controversy and confusion. Some studies find that they work a bit better than the flip of a coin, and some find that they don't. Now, a new study out of Canada adds a paradoxical twist to the mix.

On two leading instruments, generally delinquent juveniles with a prior sex offense scored higher in risk than juveniles who had committed only sex offenses. And, true to this prediction, about 13 percent of these delinquent boys went on to commit another sex offense during the 6.6-year followup period, compared with just 7 percent of the boys with only sex offenses.

But, while they did moderately well at predicting risk among the non-delinquent juveniles, neither tool could reliably predict which among the delinquent, higher-risk youngsters would go on to reoffend sexually. The two instruments were the Juvenile Sex Offender Assessment Protocol-II (J-SOAP-II) and the Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR).

A number of factors contribute to the difficulties in accurately predicting risk, especially among juveniles. These include:
  • Adolescent immaturity -- most juvenile offending is time-limited, and will spontaneously cease over time.
  • Low base rates -- it is hard to accurately predict events that have a low likelihood of occurring. In the current study, for example, only 9.4 percent of the youths were charged with another sex offense during the followup period.
  • Situational and random influences -- A lot of offending, especially among juveniles, is due to situational and environmental factors rather than personality variables, and these are extraordinarily hard to predict. (See this PSYBLOG post for a social psychology experiment demonstrating the underappreciated influence of situational variables.)
It all gets back to the larger problem I discussed in last week's report on the British metaanalysis of violence risk prediction tools: Maybe we will never find the Holy Grail. Maybe we've reached the summit of the mountain, and it’s time to step back.

The new study, by Gordana Rajlic and Heather M. Gretton of the Youth Forensic Psychiatric Services in Burnaby, British Columbia, is "An Examination of Two Sexual Recidivism Risk Measures in Adolescent Offenders: The Moderating Effect of Offender Type." It was published in the latest issue of Criminal Justice and Behavior and is available for free from Sage Publications for a limited time.

Related blog resources:

No comments:

Post a Comment

 
Real Time Web Analytics