Native of Menzelen near Xanten in Lower Rhein, he was admitted to a minor seminary (secondary school) of the Divine Word Missionaries (SVD) in Steyl in 1901. After joining the SVD, he continued his education in the Missionary Major Seminary (St. Gabriel’s House) in Mödling near Vienna (1905–11) and was ordained priest there in 1911 (with M. Gusinde and P. Schebesta, among others). Illness made him abandon further biblical studies which he had started in Rome. Back at St. Gabriel, he was assigned to the editorial staff of the journal Anthropos and began a new study in the fields related to his new assignment (ethnology, Indology, linguistics) at the University of Vienna. He successfully completed it, defending his thesis “The Ethnological Economic Research. A Historical-Critical Study” (1917). He accompanied Martin Gusinde on his third trip to Tierra del Fuego (1922). Back at St. Gabriel, he was appointed the editor of Anthropos, a task which he carried on for several years (1923-31) along his teaching and organisational activities at the University of Vienna. When Anthropos Institute was launched (1931), Koppers was designated as its vice-director. He obtained his post-doctoral degree (Habilitation) at the Department of General Anthropology, University of Vienna and later (1935) the professorial title and position. He organised and led the Institute of Ethnology at the University of Vienna (1929). Expelled from the University’s teaching staff after Austria was annexed by Nazi Germany (March 1938), he left for a research trip to India. A threat of internment by the British (due to the outbreak of the Second World War) made him return to Europe. He settled at the new seat of Anthropos Institute in Posieux, Switzerland, and stayed there (although unwillingly) until the end of the war. In 1945, he was reinstated to his position at the University of Vienna and taught there until his retirement in 1957. He died at St. Gabriel’ House in Mödlig in 1961.
He was a diligent scholar but his lectures were deeply rooted in cultural theory and strongly theoretically oriented. He proved to be a good organiser, though, and successfully maintained contacts with various international sponsoring organisations.