Final answer:
The major course of change during the midcareer stage is the social task of generativity versus stagnation.
Step-by-step explanation:
In the midcareer stage, the major course of change is the social task of generativity versus stagnation. Generativity involves finding one's life's work and contributing to the development of others through activities such as volunteering, mentoring, and raising children. Those who do not master this task may experience stagnation, having little connection with others and little interest in productivity and self-improvement.