Konrad Lorenz (kôn´rät lôr´ĕnts), 1903–89, Austrian zoologist and ethologist. He received medical training at the Univ. of Vienna and spent two years at the medical school of Columbia Univ. He received a Ph.D. (1936) in zoology from the Univ. of Munich and subsequently taught at Vienna and Königsberg. For his work in establishing the science of ethology, particularly his studies concerning the organization of individual and group behavior patterns, Lorenz was awarded the Nobel Prize for Physiology or Medicine in 1973. He derived his insights into behavior from studying fish and birds, most extensively the greylag goose. With Oscar Heinroth, he discovered imprinting, an especially rapid and relatively irreversible learning process that occurs early in the individual's life. A central concept complementary to imprinting is the innate release mechanism, whereby organisms are genetically predisposed to be especially responsive to certain stimuli. Some of his views are expressed in the popular book On Aggression (tr. 1966). His assertion that aggressive impulses are to a degree innate, and the analogies he draws between human and animal behavior, have engendered considerable controversy. After World War II, a Max Planck Institute was established for Lorenz's group of students and coworkers in ethology. Lorenz is a foreign member of the Royal Society of London.