Rosenzweig was born on September 12, 1922, in Rochester, New York, to Jews of Eastern European origin,[1] in which his bilingual parents (his lawyer father and homemaker mother spoke both English and German) helped foster an interest in language and learning.

[2] Following the completion of his studies in 1944, he enlisted in the United States Navy, initially serving as a radar technician at the Anacostia Naval Station.

[3] His thesis showed that the connections between the cochlea and the cerebral cortex could be monitored using electrodes placed on the scalp, without requiring cranial surgery.

[2] Rosenzweg was hired by the University of California, Berkeley in 1949 as an assistant professorship in physiological psychology, and remained on its faculty until he retired in 1991.

Mark Rosenzweig with his colleagues David Krech, Edward Bennett and Marian Diamond started this research in the late 1950s by comparing single rats in normal cages, and those placed in ones with toys, ladders, tunnels, running wheels in groups.