Parenting group composition does not impact program effects on children's conduct problems.

Many established parenting programs for children's conduct problems are delivered in groups. Various, and at times conflicting, beliefs exist about whether families fare better in groups with parents that are more similar to them, or in groups that are more diverse. We set out to test these beliefs empirically. We integrated data from four trials of the Incredible Years parenting program in the Netherlands, including 452 families (children age 2-10 years) participating in 44 parenting groups. We used multilevel regression to test whether families benefit more (or less) when they participate in a group with parents that are more similar to them in terms of ethnic background, educational level, and children's baseline conduct problems, Attention Deficit/Hyperactivity Disorder (ADHD) symptoms, and emotional problems. In addition, we tested whether relative group position effects were stronger for some families than for others (e.g., whether especially ethnic minority families benefit from groups that are more ethnically diverse). Families with more severe conduct problems benefited more, but they did not fare better (or worse) in groups where other families were more similar to them. Regarding the other group characteristics, families' relative group position did not predict parenting program effects on children's conduct problems. Our findings held across families with different sociodemographic backgrounds and different levels of children's ADHD symptoms and emotional problems. We found no evidence that parenting group composition impacts the effectiveness of the Incredible Years parenting program for children's conduct problems. (PsycInfo Database Record (c) 2021 APA, all rights reserved).