Parenting styles are crucial in the process of forming social emotions in children. They are also vital for creating effective family policies in order to improve a child’s early development. As such, it is important to acknowledge the enduring association of parenting styles across generations, as well as their impact on early child development. In this study, the question as to whether the warm and hostile parenting styles of a parent/grandparent mediate the relationships between the emotional warmth and rejection parenting styles of a grandparent/great grandparent, as well as the subsequent social–emotional development of a grandson/great grandson and/or a granddaughter/great granddaughter, was examined. Cross-sectional assessment data from 194 primary caregivers of children between 6 and 36 months were analyzed using mediation analyses. In addition, moderated mediation models were used to test heterogeneity effects. This study found evidence that the warm and hostile parenting styles of a parent/grandparent mediated the associations between the emotional warmth and rejection parenting styles of a grandparent/great grandparent, as well as the subsequent socio-emotional development of a grandchild/great grandchild. Parents/grandparents tend to use a warm parenting style when the child is a boy, thereby resulting in fewer socio-emotional problems. This study provides empirical evidence for the purposes of preventive services to improve caregivers’ parenting styles in the early stages of a child’s development. Researchers and family practitioners should continue to support families with intervention or therapeutic techniques in order to mitigate potential lasting consequences.