There is one phase of psychopathology having such fundamental influence upon the integrity of the social structure that it alone would demand the development of a "psycho-clinic" namely, that of crime. Crime, we are prepared to admit, is a social-economic manifestation. Economic pressure, playing the game of self-interest too roughly, using ingenuity to avoid labor, short-circuiting the currents of profit, exploiting the feeble, is a sufficient temptation to human nature to make eternal vigilance and effective education the price of public safety. None the less the prevalence of crime is as intimately a question of maladjustment, neural inadequacy, and psychopathic trends. All that society demands is crime insurance. The nature of the criminal instincts is a matter for psychological diagnosis; treatment must follow psychological guidance. As a remedial measure the present system has failed. Crime shades into delinquency, and delinquency into minor maladjustments. Crime is so largely a juvenile phenomenon, a question of management of unruly urges, that it stands as a constant menace to the security of the maturing process. Criminal psychology1 covers every aspect of society's dealings with offenders. As a clinical problem, 1 See Gross, H.,"Criminal Psychology," Little, Brown & Company, Boston, 1911.it is that of the management of low-grade individuals with weak resistances and strong temptations. The influence of the approaches of modern psychology appears at every phase of the social provisions for the guidance and treatment of criminals. The modification of criminal procedure presumably will proceed slowly as a consequence of the heavy cost and inefficiency of established methods. The institution of juvenile courts, which provide for intimate case histories and examinations of the offenders under the guidance of a psychiatrist who sits with and advises the judge, the establishment of institutions like the Judge Baker Foundation in Boston for the study of delinquency, form practical evidence of the growing confidence in the psychological approach to the problems of crime.1

By such route we reach an extension of the psychological disciplines in a significant direction, that of the social structures which men have instituted to express and satisfy their mental needs. The data of social psychology are ancient, their interpretation modern. Sociology grew to an independent estate by staking a claim at the frontiers of several sciences where their boundaries failed to meet. Psychology thus includes not only mental processes but mental products.

With his characteristic insight Freud recognized early that if the mechanisms whose issues he was then tracing in the neurotic field had any claim to universal significance, that claim must be justified by discovering the issues of similar motivations in the cultural products of mankind. In the same spirit of a psychoanalytic explorer, he found complex expressions in wit and humor, in art and literature, that could be translated into the Freudian formulae. Wit was letting the cat out of the bag, or a self-betrayal; art 1 See Healey, W.,"Mental Conflicts and Misconduct," Little, Brown & Company, Boston, 1917. and literature disclosed Narcissistic trends. Narcissus, like Oedipus, grew out of the unconscious artistic following of clues deeply imbedded in the psychic nature; Greek and Roman fantasies achieved a renaissance in psycho-neuroses.But even more directly pertinent is the tracing of these trends in the anthropological institutions of totem and taboo, the protections and prohibitions by which the primitive mind had safeguarded its unconscious recognition of psychic values, culturally expressed. Freud's contributions to psycho-anthropology are incidental. The anthropologists, from Tylor to Levy-Bruhl and Boas and Radin, and from Spencer to Frazer and Crawley and Malinowski and Briffault, have laid the foundations for a psychology of primitive mentality that has important consequences in the interpretation of human cultures, low and high, simple and evolved. To cap this edifice with the social psychology of our own economic, political, and social management, was the completing stage. Meanwhile the folklore movement had gathered inexhaustible material for tracing the story of mind in its popular expressions. The psychology of the crowd, from Le Bon to Trotter and Conway and Martin (who applies the Freudian concepts), sets forth alike the products of gregariousness and of the collective integration in which communities have their being. Social psychology has become a specialty of large proportions; it, too, dates from the application of evolutionary concepts to the social structure. It would have been impossible without the collateral contributions of the several developments that came in the wake of the renaissance of psychology in a brief half century. It brings evolution once more to the forefront.

Applied psychology may be briefly surveyed. Its fons et origo lies in the modern pragmatic attitude, which asserts that if psychology is an actual working clue to the life of the mind, individually and collectively, it must leave the academic confines of a specialty or the narrow loyalties of a "pure" science - an ideal still cherished in early experimental days - and launch out upon the world of human relations and practical enterprises. Psychology must"work" and be put to work.

Distinctive in this development is the story of mental testing - distinctive because it arises from so central a problem as the nature of intelligence and was guided by so practical an aim as to provide a measuring scale applicable to a great variety of uses. It arose from the desirability of detecting the subnormal children, incapable of following the program of the schools fitted to normal requirements. It has come to be an instrument employed in education, in psychiatry, in the case histories of the dependent and delinquent classes, and in industrial occupations. Intelligence is a flexible term; it has its basis in the general level of development, the neuronic adequacy and finer organization of the higher brain centers, and in the development of these highly specialized structures. We are not musical and mechanical and acrobatic and graceful and socially adaptable and apt at analysis and deep reflection, by virtue of quite the same patterns of development, the same supply and organization of engrams. And that basic fact itself gives rise to an engaging division of modern psychology of which Sir Francis Galton is the founder - "The Psychology of Individual Differences."1