In 1951, ER answered this question in a Look article entitled "The Seven People Who Shaped My Life." Most of her response focused on her personal life; therefore, she credited her parents, her aunt Pussie (Mrs. W. Forbes Hall Morgan), her teacher Marie Souvestre, FDR, her mother-in-law, Sara Delano Roosevelt, and Louis Howe, the Roosevelts' political mentor and the architect of FDR's political career, as having the strongest influence on her personality and character.

As ER moved into the political arena, she formed close friendships with women who tutored her in organizational development and political strategy. Women's Trade Union League leader Rose Schneiderman introduced ER to immigrant communities, women workers, and organized labor. English professor Esther Lape brought ER into the Women's International League for Peace and Freedom and encouraged her efforts on behalf of the League of Nations and the Bok Peace Prize. New York State Democratic Party activists Marion Dickerman and Nancy Cook brought ER into the postsuffrage woman's movement and the state party hierarchy. Associated Press reporter Lorena Hickok played a key role in shaping ER's journalism career and also served as strategist and confidante. National Council of Negro Women President and National Youth Administration (NYA) official Mary McLeod Bethune and NAACP Executive Secretary Walter White helped ER address racism and champion civil rights.

ER also developed close relationships with a variety of reform-minded men. Financier Bernard Baruch appreciated ER's political savvy and for decades remained her close advisor on international finance and domestic economics. Social worker Harry Hopkins encouraged her commitment to progressive social policy and, as New Deal administrator, helped ER cut through bureaucratic red tape. She treasured her friendship with Joe Lash, whom she first met in 1939 when he was a leader of the American Youth Congress, for more than twenty years. Lastly, she formed an especially close bond with David Gurewitsch, the physician she met in 1944 when he treated Joe Lash's wife, Trude.