Ramona Mercer developed the Maternal Role Attainment Theory in the 1970s based on her experience as a nurse and research on mothers. The theory proposes that a mother acquires competence in her maternal role over time through a process of attachment to her infant, learning caretaking skills, and finding satisfaction in her role. Mercer identified numerous factors like age, social support, infant health and cues that can influence a woman's attainment of the maternal role. She refined the theory over her career and emphasized nursing's important role in supporting women's transition to motherhood.