Final answer:
A son acting on his mother's behalf is her legal representative or attorney-in-fact. This reflects historical practices where family roles and legal responsibilities varied between sons and daughters, with sons often bearing more legal responsibilities towards family matters.
Step-by-step explanation:
If a son has the legal right to act on his mother's behalf, the son is his mother's legal representative or attorney-in-fact when this authority is designated through a legal document like a power of attorney. In such a relationship, the son is legally empowered to make decisions and take action in the best interest of his mother, especially in cases where she may not be able to do so herself due to incapacity or other reasons.
The concept of children taking legal responsibility for their parents has historical roots, with laws and practices varying from one culture to another. For instance, in Roman law, if a son died before his mother, she could dispose of his property, as seen in Han practice and law, where a son after a father's death might inherit debt and property, thereby upholding the family's reputation and prosperity.
Treating sons and daughters differently has a long history, with sons often having more responsibilities toward family property and reputation, whereas daughters might handle domestic responsibilities or have dowries that remain their property. These differences are rooted in cultural norms and legal frameworks that have provided distinct roles for sons and daughters throughout history.