Trinkaus was born on 23 May 1918 at his childhood home in Rockville Center, New York, to Franciska Magdalena Krüger and Charles Edward Trinkaus. In his autobiography, Trinkaus described his early childhood as one typical of “respectable, middle-class, white-collar, Protestant” families during those years (Trinkaus 2003, 3). His parents were both republicans and devout Methodists, as was Trinkaus until he became an atheist during his late teenage years. Trinkaus claimed that his proximity to the Atlantic Ocean as a child, along with its estuaries and salt marshes, provided many occasions to explore his natural surroundings and to swim and fish, contributing to his life-long interest in biology. Before he entered college at Wesleyan University in Middletown, Connecticut, Trinkaus attended public school, where he recalled fond memories of his first exposure to the study of natural history and biology, as well as his talent and love for drama.