A systematic review with a meta-analysis conducted by the Campbell Collaboration in 2006 examined the results of 55 impact evaluations of training programs for parents of children up to 5 years of age. This review concluded that such programs have a small to medium impact (d=0.35 on average) on the incidence of child behavior problems, and that there are benefits in terms of reducing antisocial behavior and juvenile delinquency among children of parents who participated in these programs. Furthermore, according to the authors, evidence indicates that these improvements are sustained in the long term, bringing lasting benefits to the lives of those children [1].
This same review was updated in 2016. This new version reaffirmed the conclusion that parent training programs are an effective strategy to prevent antisocial behavior and delinquency. In this case, the authors estimated a positive and statistically significant effect (d=0.37), which corresponded to a total of 32 individuals (out of 100) that committed a registered offense in the treatment group, while in the control group a total of 50 out of 100 individuals were recorded [2].
A third systematic review (from 2020) identified and analyzed three experimental or quasi-experimental studies that evaluated programs that include positive parenting activities combined with other content aimed at preventing intimate partner violence. The programs evaluated and analyzed by the authors of this systematic review are relatively long in duration (between 9 and 15 group sessions) and focus on promoting critical reflection and dialogue, as well as providing support to men who are transitioning to fatherhood. Two of the studies included in the review showed positive impacts, while another showed promising results in terms of reducing intimate partner violence [3].