What Works For Sexual Offenders?

What Works For Sexual Offenders? PDF Version (20KB)

Research summary
Vol. 14 No. 2
March 2009


Do the principles of effective intervention for general offenders also apply to treatments for sexual offenders?


Although there is general agreement that certain forms of intervention can effectively reduce the recidivism rates of general offenders, there is less agreement about the effectiveness of treatment for sexual offenders. Sex offenders are often considered to have unique characteristics (e.g., sexual deviance), which may be particularly hard to change or manage.

For general offenders, the interventions that have proved to be the most successful are those that follow the principles of risk, need and responsivity (RNR). The risk principle states that the most resources should be directed to the offenders with the highest risk of recidivism, with little or no interventions for the lowest risk offenders. The need principle directs intervention toward factors related to recidivism risk (criminogenic needs), and the responsivity principle tells treatment providers to adapt interventions to the personal learning style of the offenders.

The validity of the RNR principles for general offenders has been documented in a large number of studies and reviews. Previous reviews of the sexual offender treatment studies have noted different results for different treatments. The current review examined the extent to which this variation in treatment outcome can be explained by adherence to the RNR principles.


A thorough review of the sexual offender treatment literature was conducted, identifying 23 studies that met basic criteria for research quality. The effectiveness of treatment was measured by comparing the recidivism rates of treated and untreated offenders. Each treatment was then coded by an independent, impartial rater as to the extent to which it adhered to the RNR principles.


Across all treatments, the recidivism rates for the treated offenders was lower than the rates for the comparison groups for both sexual recidivism (11% versus 19%, sample size of 6,746) and general recidivism (32% versus 48%, sample size of 4,801).

The treatments that were most effective were those that adhered to the RNR principles of effective corrections. On average, the treatments that followed all three principles showed recidivism rates that were less than half the recidivism rates for the comparison groups. In contrast, the recidivism rates for treatments that followed none of the RNR principles had no effect on recidivism.

Policy implications

  1. As with general offenders, appropriate human service intervention should be a part of the correctional management of sexual offenders.
  2. Sexual offender treatment programs should be reviewed to determine their adherence to the risk, need and responsivity principles of effective correctional treatment.
  3. Further research is needed to determine the extent to which sexual offenders have unique criminogenic needs, and to determine the amount of treatment required to reduce recidivism for  offenders at different risk levels.


For further information

R. Karl Hanson, Ph.D.
Corrections Research
Public Safety Canada
340 Laurier Avenue West
Ottawa, Ontario
K1A 0P8
Tel (613) 991-2840
Fax (613) 990-8295
e-mail Karl.Hanson@ps-sp.gc.ca

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