Robert Yerkes made significant contributions to modern psychology in many ways, impacting many different areas of the discipline. Of these contributions, three have had the most influence on modern psychology today. The first major contribution and certainly the one which had his greatest impact in psychology focuses on Yerkes' research which he carried out in the very first American primate laboratory which he himself founded. Another major influence Yerkes had on psychology today was his work on intelligence testing of American military recruits during World War I. Finally, the last influence discussed was his development of the Yerkes-Dodson law and its impact on how we understand the relationship between arousal and performance today. After years at Yale, in 1930 Yerkes was finally able to study primates in a laboratory that was previously unprecedented in the United States. In this laboratory located in Orange Park, Florida, he was able to conduct numerous primate research studies that addressed many different areas of the field of psychology, such as sensory function, habit formation, and problem solving. problems (Dewsbury, 2000). Dewsbury (2000) argues that Yerkes' research projects, focusing on these aspects of psychology and further extending the realm of animal experimentation, were his major contributions to modern psychology, and that Yerkes was able to lay the foundations for similar searches. carried out and which can still be seen today. Other contributions to modern psychology for which Yerkes is responsible include the development of a new form of comparative psychology which he used in his research, as well as its creation...... middle of article.. ....said of Habit-Training. Mr. Bar-Eli. Editor and D. Smith. Publisher (ed.). In Essential Readings in Sport and Exercise Psychology.13-22. Champaign, IL: Human Kinetics. Elliot, R. M. (1956). Robert Mearns Yerkes: 1876-1956. The American Journal of Psychology, 69:3. 487-494.Shultz, DP and Shultz, SE (2011). A History of Modern Psychology. United States: Cengage Learning. Triplet, RG (1982). The relationship between Clark L. Hull's hypnosis research and his theory of later learning: the continuity of his life's work. Journal of the History of the Behavioral Sciences, 18. 22-31.Yerkes, Robert M. and Yerkes, A.W. (1936). Nature and conditions of the avoidance (fear) response in chimpanzees. Journal of Comparative Psychology, 21, 53-66. Yerks, R. M. (1932). Robert Mearns Yerkes. In A History of Psychology in Autobiography, Vol II. C. Murchison (ed.). Worcester, MA: Clark University Press.