Hefner was born into a Methodist family, to Glenn Hefner, an accountant, and Grace (Swanson) Hefner, a teacher, on April 9, 1926 in Chicago, Illinois. He was raised in Woodlawn, Chicago. Hefner served in the US Army (1944 - 1946). He attended the Art Institute of Chicago (1946), the University of Illinois at Urbana-Champaign, earning a BA in Psychology (1949), and Northwestern University, 1949.