This survey indicates the present status of attempts to define and measure differences in original and human nature. A knowledge of individual differences is important in every field of social control. It is significant that these tests have been devised to meet problems of policies and of administration in medicine, in industry, in education, and in penal and reformatory institutions. Job analysis, personnel administration, ungraded rooms, classes for exceptional children, vocational guidance, indicate fields made possible by the development of tests for measuring individual differences. SELECTED BIBLIOGRAPHY I. ORIGINAL NATURE A. _Racial Inheritance_ (1) Thomson, J. Arthur. _Heredity._ London and New York, 1908. (2) Washburn, Margaret F. _The Animal Mind._ New York, 1908. (3) Morgan, C. Lloyd. _Habit and Instinct._ London and New York, 1896. (4) ----. _Instinct and Experience._ New York, 1912. (5) Loeb, Jacques. _Comparative Physiology of the Brain and Comparative Psychology._ New York, 1900. (6) ----. _Forced Movements._ Philadelphia and London, 1918. (7) Jennings, H. S. _Behavior of the Lower Organisms._ New York, 1906. (8) Watson, John. _Behavior: an Introduction to Comparative Psychology._ New York, 1914. (9) Thorndike, E. L. _The Original Nature of Man._ Vol. I of "Educational Psychology." New York, 1913. (10) Paton, Stewart. _Human Behavior._ In relation to the study of educational, social, and ethical problems. New York, 1921. (11) Faris, Ellsworth. "Are Instincts Data or Hypotheses?" _American Journal of Sociology_, XXVII (Sept., 1921.) B. _Heredity and Eugenics_ 1. Systematic Treatises: (1) Castle, W. E., Coulter, J. M., Davenport, C. B., East, E. M., and Tower, W. L. _Heredity and Eugenics._ Chicago, 1912. (2) Davenport, C. B. _Heredity in Relation to Eugenics._ New York, 1911. (3) Goddard, Henry H. _Feeble-mindedness._ New York, 1914. 2. Inherited Inferiority of Families and Communities: (1) Dugdale, Richard L. _The Jukes._ New York, 1877. (2) M'Culloch, O. C. _The Tribe of Ishmael._ A study in social degradation. National Conference of Charities and Correction, 1888, 154-59; 1889, 265; 1890, 435-37. (3) Goddard, Henry H. _The Kallikak Family._ New York, 1912. (4) Winship, A. E. _Jukes-Edwards._ A study in education and heredity. Harrisburg, Pa., 1900. (5) Estabrook, A. H., and Davenport, C. B. _The Nam Family._ A study in cacogenics. Cold Spring Harbor, N.Y., 1912. (6) Danielson, F. H., and Davenport, C. B. _The Hill Folk._ Report on a rural community of hereditary defectives. Cold Spring Harbor, N.Y., 1912. (7) Kite, Elizabeth S. "The Pineys," _Survey_, XXXI (October 4, 1913), 7-13. 38-40. (8) Gesell, A. L. "The Village of a Thousand Souls," _American Magazine_, LXXVI (October, 1913), 11-13. (9) Kostir, Mary S. _The Family of Sam Sixty._ Columbus, 1916. (10) Finlayson, Anna W. _The Dack Family._ A study on hereditary lack of emotional control. Cold Spring Harbor, N. Y., 1916. II. HUMAN NATURE