Mack was initially a student and later a close confidant of and collaborator with Sigmund Freud and was responsible for much of the fleshing out of Freudian theory.
Brunswick pioneered the psychoanalytic treatment of psychoses, and the study of emotional development between young children and their mothers, and the importance of this relationship in creating mental illness.
She graduated from Radcliffe College in 1918 under the tutelage of Elmer Ernest Southard, an eminent Harvard scholar, who initiated her interest in psychology.
Rejected by Harvard University because of her gender, Brunswick went to Tufts Medical School, where she finally received her M. D. cum laude in 1922.
Ruth had fallen in love with a man five years younger than herself, and got married a second time in March 1928 to Mark Brunswick, an American composer.
This rivalry was exacerbated when Freud gave Brunswick access to one of his most illustrious patients, the "Wolf-man", which Anna was also expecting to have.
Brunswick pioneered the psychoanalytic treatment of psychoses, and the study of emotional development between young children and their mothers, and the importance of this relationship in the genesis of mental illness.