Definitions for yerkesˈyɜr kiz
Random House Webster's College Dictionary
Charles Tyson, 1837–1905, U.S. financier.
Robert Mearns, 1876–1956, U.S. psychologist and psychobiologist.
Yerkes, Robert M. Yerkes, Robert Mearns Yerkes(noun)
United States psychologist who studied the intelligence of primates (1876-1956)