3. Research in the Field of Original Nature
Valuable materials for the study of human nature have been accumulated in archaeology, ethnology, and folklore. William G. Sumner, in his book Folkways, worked through the ethnological data and made it available for sociological use. By classification and comparison of the customs of primitive peoples he showed that cultural differences were based on variations in folkways and mores in adaptation to the environment, rather than upon fundamental differences in human nature.
The interests of research have resulted in a division of labor between the fields of original and acquired nature in man. The examination of original tendencies has been quite properly connected with the study of inheritance. For the history of research in this field, the student is referred to treatises upon genetics and evolution and to the works of Lamarck, Darwin, DeVries, Weismann, and Mendel. Recent discoveries in regard to the mechanism of biological inheritance have led to the organization of a new applied science, "eugenics." The new science proposes a social program for the improvement of the racial traits based upon the investigations of breeding and physical inheritance. Research in eugenics has been fostered by the Galton Laboratory in England, and by the Eugenics Record Office at Cold Spring Harbor in the United States. Interest has centered in the study of the inheritance of feeble-mindedness. Studies of feeble-minded families and groups, as The Kallikak Family by Goddard, The Jukes by Dugdale, and The Tribe of Ishmael by M'Culloch, have shown how mental defect enters as a factor into industrial inefficiency, poverty, prostitution, and crime.
4. The Investigation of Human Personality
The trend of research in human nature has been toward the study of personality. Scientific inquiry into the problems of personality was stimulated by the observation of abnormal behavior such as hysteria, loss of memory, etc., where the cause was not organic and, therefore, presumably psychic. A school of French psychiatrists and psychologists represented by Charcot, Janet, and Ribot have made signal contributions to an understanding of the maladies of personality. Investigation in this field, invaluable for an understanding of the person, has been made in the study of dual and multiple personality. The work of Freud, Jung, Adler, and others in psychoanalysis has thrown light upon the rôle of mental conflict, repression, and the wishes in the growth of personality.
In sociology, personality is studied, not only from the subjective standpoint of its organization, but even more in its objective aspects and with reference to the rôle of the person in the group. One of the earliest classifications of "kinds of conduct" has been ascribed by tradition to a disciple of Aristotle, Theophrastus, who styled himself "a student of human nature." The Characters of Theophrastus is composed of sketches—humorous and acute, if superficial—of types such as "the flatterer," "the boor," "the coward," "the garrulous man." They are as true to modern life as to the age of Alexander. Chief among the modern imitators of Theophrastus is La Bruyère, who published in 1688 Les caractères, ou les mœurs de ce siècle, a series of essays on the manners of his time, illustrated by portraits of his contemporaries.
Autobiography and biography provide source material for the study both of the subjective life and of the social rôle of the person. Three great autobiographies which have inspired the writing of personal narratives are themselves representative of the different types: Caesar's Commentaries, with his detached impersonal description of his great exploits; the Confessions of St. Augustine, with his intimate self-analysis and intense self-reproach, and the less well-known De Vita Propria Liber by Cardan. This latter is a serious attempt at scientific self-examination. Recently, attention has been directed to the accumulation of autobiographical and biographical materials which are interpreted from the point of view of psychiatry and psychoanalysis. The study Der Fall Otto Weininger by Dr. Ferdinand Probst is a representative monograph of this type. The outstanding example of this method and its use for sociological interpretation is "Life Record of an Immigrant" contained in the third volume of Thomas and Znaniecki, The Polish Peasant. In connection with the Recreation Survey of the Cleveland Foundation and the Americanization Studies of the Carnegie Corporation, the life-history has been developed as part of the technique of investigation.
5. The Measurement of Individual Differences
With the growing sense of the importance of individual differences in human nature, attempts at their measurement have been essayed. Tests for physical and mental traits have now reached a stage of accuracy and precision. The study of temperamental and social characteristics is still in the preliminary stage.
The field of the measurement of physical traits is dignified by the name "anthropometry." In the nineteenth century high hopes were widely held of the significance of measurements of the cranium and of physiognomy for an understanding of the mental and moral nature of the person. The lead into phrenology sponsored by Gall and Spurzheim proved to be a blind trail. The so-called "scientific school of criminology" founded by Cesare Lombroso upon the identification of the criminal type by certain abnormalities of physiognomy and physique was undermined by the controlled study made by Charles Goring. At the present time the consensus of expert opinion is that only for a small group may gross abnormalities of physical development be associated with abnormal mental and emotional reactions.