Dino Study: Daily Intervention-based Research on Nurturing Opportunities in Young Children

The goal of this clinical trial is to evaluate the effectiveness of the Incredible Years Dinosaur Program in children aged 4 to 8 years with conduct problems. The main questions it aims to answer are: * Does participation in the Dinosaur Child Program lead to greater improvements in children's emotional, social, and cognitive functioning, and reductions in externalizing behavior compared to a waitlist control group? * Does the intervention reduce emotional variability and daily behavior problems as captured through daily diary assessments? * Does the intervention improve daily parent-child dynamics, including reduced emotional escalation and more shared positive affect? Researchers will compare children in the intervention group to those in the waitlist control group to see if the program leads to better emotional regulation, fewer behavior problems, and improved parent-child interactions. Participants will: * Be randomly assigned to either the intervention or waitlist control group (1:1) Receive 18 weekly small-group sessions (if in the intervention condition) using the Incredible Years Dinosaur Program * Complete daily diaries with their parent using the m-Path app during a 20-week period (baseline, intervention, follow-up) * Complete standardized pre- and post-intervention assessments via parent, teacher, and child reports

Inclusion Criteria: * Children aged 4 to 8 years * At least one parent or primary caregiver willing and able to participate in the study and complete daily diary assessments * Sufficient Dutch language proficiency in child and parent to complete questionnaires and daily diary reports * Parental indication that the child shows elevated or (sub)clinical levels of conduct problems in daily life (e.g., frequent defiance, aggression, or rule- breaking behavior Exclusion Criteria: * Intellectual disability in the child (IQ \< 70) * Child lives primarily in a different household during weekdays (e.g., institutional care, full-time co-parenting arrangement) * Parent/child does not have sufficient Dutch language proficiency