Final answer:
Interacting personalities
Step-by-step explanation:
The aspect of family dynamics that primarily involves the study of different personalities within a family unit is Interacting personalities. Interactionists recognize how family status roles are socially constructed and how they influence social behavior. Family members are like actors who come together to act out their parts in constructing a family. For example, the role of a 'good father' has evolved over time to include not just financial security but also emotional well-being and intellectual growth of the children.