Granger was educated at Hotchkiss School, graduating in 1925, and Yale University, graduating in 1929.
[1] He was a member of the Skull and Bones secret society.
[2] Costikyan was with the New York Trust Company from 1929 to 1959, and became a partner of Brown Brothers Harriman in 1969.
[3] He was Vice President of the Chemical Bank of New York, from 1959 to 1962; and Senior Vice President of the First Bank Stock Corporation of Minneapolis, from 1962 to 1969.
[4][5] Costikyan also served as Chairman of the First Bank System of Minneapolis.