The aim of this research is to study the relationship between altruism and the development of the family business by creating new units. The information, collected through semi-structured interviews with managers who are owners of five cases of family businesses, was the subject of a thematic content analysis. This study shows that the creation of new family units is to ensure the well-being of family members by avoiding conflicts. This addresses the concern of parents about the future of their successors and to ensure the evolution of the family and its development within the framework of a patrimonial logic. For the successors with different profiles, the development takes place through diversification.