IntroductionGrandparenting is a prevalent form of early childcare in rural China, yet its long-term effects on adolescent development remain controversial. This study investigates whether early childhood grandparenting, compared with parental care, influences deviant behaviors among rural junior high school students and explores the mediating mechanisms and heterogeneous effects.MethodsUsing data from the China Education Panel Survey, this study analyzed a sample of 4,746 rural junior high stude