Informal reasoning is critical in forming the foundation for individual discernment of what makes a good decision in order to pursue a life that one has reason to value. In psychological literature, the research on children’s development of this skill has been sparse. As most children begin to learn these skills from daily interactions with their parents in the family, in this study a structural equation model was developed with regards to the development of informal reasoning as influenced by parenting dimensions, home communication patterns and socioeconomic status (SES). Past research has consistently demonstrated an inequality in educational achievement in relations to SES, especially in the German context of successful schooling. Present results suggest that parents of lower SES display higher control, which leads to a more conformity-oriented family communication pattern, thus hampering a child’s development of informal reasoning. However, responsiveness of parents increases with the level of SES and contributes to more conversation-oriented practices. These results provoke us to consider the continual far-reaching influence of SES beyond formal education as mediated by parenting. Understanding the influence of these developmental variables on reasoning is significant in helping educators to provide the optimal conditions for a possible disadvantaged child.