Final answer:
Psychodynamic therapy is the approach that asserts that unresolved emotional reactivity to one's family must be addressed to achieve a mature and unique personality.
Step-by-step explanation:
The approach that asserts that unresolved emotional reactivity to one's family must be addressed to achieve a mature and unique personality is Psychodynamic therapy.
Psychodynamic therapy is a therapeutic approach that focuses on understanding unconscious processes and childhood experiences that shape an individual's personality and behavior. By addressing unresolved emotional issues related to one's family dynamics, psychodynamic therapy aims to promote personal growth and development.