Final answer:
Oprah Winfrey was primarily socialized by her family members, especially her grandmother and later her father, who were key influencers in her early development and later in her adolescence.
Step-by-step explanation:
The most important socializing agents for Oprah during her development were her family members. Initially, it was her grandmother who played a significant role in socializing her by teaching her to read at an early age of 3, which is indicative of early nurturing found in familial settings. As her circumstances changed, other family members, particularly her father, became key socializing agents, imparting strict behavioral expectations that led to a semblance of stability and academic success during Oprah's tumultuous adolescence.
Family is often the first and the most impactful agent of socialization, as highlighted in Oprah's life by her interactions with her grandmother, mother, and father. Her grandmother's involvement during her early years in rural Mississippi and her father's discipline when she moved to Nashville are exemplary of the strong influences family can have. This aligns with the sociological perspective that family shapes a person's initial worldview and is foundational for early development.