While it may seem like recidivism has a clear definition, there have actually been a number of different definitions of recidivism over time. Generally, recidivism means reoffending after being released from a punishment or treatment program. However, measures of recidivism cannot really account for all recidivism because recidivism is measured in various ways such as convictions for additional crimes, self-reporting rates, etc., but none of these measures is going to accurately capture all instances of recidivism. One highly-researched area of recidivism is sex offenders and sex-based offenses. Most lay people believe that sex offenders cannot be rehabilitated and that they will inevitably reoffend. Therefore, it should come as no surprise that a significant portion of research on recidivism focuses on sex offenders.
One research-based aspect of recidivism is whether specialized psychological treatment can reduce recidivism rates. Gannon et al. examined this question in 2019. They used meta-analysis to examine 70 studies that looked at the impact of specific treatments with recidivism rates. This allowed them to include over 55,000 individual subjects in their study. They found that offense-specific types of treatment were effective in reducing specific types of recidivist behaviors. However, they also found that treatment programs, especially those that had consistent input and guidance from therapists for the duration of the program, were effective at helping reduce overall recidivism. In other words, not only were the subjects less likely to engage in those identified and targeted behaviors, but also less likely to engage in overall undesirable/illegal behaviors. However, a key to the success of these programs was that the treatment programs be adequately staffed, and staffing is a consistent problem in rehabilitation programs, especially those offered in jail or through probation/parole post-conviction programs.