Biography

Mary Dinsmore Salter Ainsworth was born in Glendale, Ohio, in 1913, the oldest of three daughters of Charles and Mary Salter. Ainsworth showed a talent for academics early in life, reportedly learning to read at the age of three. The Salters valued education; both Charles and Mary were graduates of Dickinson College in Pennsylvania. Ainsworth recalls the weekly visits the family took to the library and the high academic expectations her parents had for all three of their girls to attend college.

Charles Morgan Salter was employed by a Cincinnati-based manufacturing firm, and when Ainsworth was five the family moved to Toronto after his company relocated him to a branch office. Her father eventually became branch President of Aluminum Goods, Ltd., and in 1931 Ainsworth and her parents became naturalized Canadian citizens.

Mary Main, a behavioral psychologist and student of Ainsworth's,...