Dyk was born Ruth Belcher on March 25, 1901, in Portland, Maine."Dyk, Ruth (1901–2000)." Dictionary of Women Worldwide: 25,000 Women Through the Ages, edited by Anne Commire and Deborah Klezmer, vol. 1, Yorkin Publications, 2007, p. 567. Gale eBooks. Accessed 11 Oct. 2021. Her parents were Arthur Fuller Belcher, a lawyer who died when Ruth was three, and Annie Manson Belcher, who was one of the first women to attend Tufts Medical School, though the school forced her out when she married. Ruth grew up in Newton Center, Massachusetts, where Ruth and her mother marched together in Boston for women's suffrage. Dyk was later featured in Ken Burns' documentary of suffragists, Not for Ourselves Alone. Dyk attended Wellesley College as an undergraduate, graduating in 1923,Wellesley College, The Wellesley Legenda (1923 yearbook): 165. and Simmons College, earning MA in economics. She also studied at University of Wisconsin and University of California at Berkeley.
