Dieter Claessens (2 August 1921, Berlin – 30 March 1997, Berlin) was a German sociologist and anthropologist.
Returning as POW from the Soviet Union Dieter Claessens studied sociology, anthropology, and psychology in Berlin, where he got his doctorate (Dr. phil.) from the Freie Universität in 1957. He took his sociological post-doctoral degree (Habilitation) from the University of Münster, where he was called to a Chair of Sociology in 1962. 1966 he returned as professor to the Free University, and retired there 1986, continuing his research work until his death in Berlin, 1997.
He got his reputation especially for his pionieering work on the sociological dimension of both ontogenesisFamilie und Wertsystem. Eine Studie zur zweiten sozio-kulturellen Geburt des Menschen, 4. ed. 1978 and phylogenesis.Das Konkrete und das Abstrakte, 1980
Status als entwicklungssoziologischer Begriff, 1965
(with Arno Klönne, Armin Tschoepe) Sozialkunde der Bundesrepublik Deutschland]], 1965 (many editions)