EXPERIMENTS IN PERSONALITY

Experiments in Personality. Volume 1: Psychogenetics and Psychopharmacology. Volume 2: Psychodynamics and Psychodiagnostics. Edited by H. J. Eysenck, Ph.D. (Pp. 262 +xxii, illustrated; and pp. 333+viii illustrated. 40s. each.) London: Routledge and Kegan Paul. 1960. These two volumes contain further contributions to the impressive volume of work carried out by Professor Eysenck and his team in the department of psychology at the Institutes of Psychiatry, London University, over the past 15 years. These inquiries have sought to define the main dimensions of normal and abnormal personality by the application of factorial analysis to the results of personality tests. Three main factors emerged from these inquiries-a general factor of "neuroticism," a bipolar factor closely related to Jung's introversion-extraversion dichotomy, and a factor of "psychoticism. " After these preliminary statistical and taxonomic studies, Professor Eysenck moved forward to experimental inquiries into the psychophysiological basis of the dimensions he had isolated. Integrating his findings with the theories of Pavlov and Hull in relation to conditioning and learning, he proposed that introversion-extraversion was closely related to differences in conditionability between individuals; the introvert formed conditioned responses that were strong, that developed with speed, and that were resistant to extinction, while the responses of extraverts showed the converse of these features. Similar variations in the responsiveness of the autonomic system were held to be related to " neuroticism. " Eysenck further predicted that depressant drugs by their increase of cortical inhibition and decrease of cortical excitation would tend to produce extraverted behaviour patterns, while stimulant drugs would exert an opposite effect. The testing of these deductions has led to experimental work in relation to perception and learning and the effects of brain injury and drugs on psychological performance. In these volumes this work is carried a stage further with inquiries into the relationship between measures of learning, attention, and conditioning and introversion-extraversion and effects of depressant drugs upon perceptual discrimination, vigilance, reaction time, and palmar skin resistance. In an inquiry into thought disorder in psychotic patients, schizophrenics (as distinct from neurotics, depressives, and normals) were found to be over-inclusive in their thought, but no more " concrete " in thinking than other subjects with similar intelligence, nor any less retarded than depressives. There is a group of papers on canonical variate analysis, a statistical technique based upon different assumptions than factorial analysis, but which leads to essentially similar conclusions about personality structure. Ingenious use of it is made by the Eysencks for the development of a method of classification of drugs in terms of their effects on performance in psychological tests. Some of the findings in the experimental inquiries cnfirmed the predictions made. Thus, hysterics and -dysthymics behaved in most tests of attention, learning, and perceptual tasks " in a manner suggestive of, respectively, high and low levels of central inhibition. " One depressant drug decreased the number of conditioned responses but another failed to produce a significant effect. A number of the findings, moreover, failed to substantiate the initial postulates. Thus, the conditioning measures employed by Willett did not, on the whole, correlate with extraversion-introversion, nor was there the predicted correlation between perceptual tests and extraversion that might have suggested they were different aspects of the same process. Professor Eysenck's confidence in his theories seems unshaken by such discrepancies. He regards his theories as belonging to the " weak " category for which successful predictions provide support, whereas failures, which would have been disastrous for a " strong" theory, need not be taken too seriously. It is often wise as well as courageous, when working in a relatively unexplored field, not to allow a single " brute fact " to destroy a beautiful hypothesis. But it then needs a rare objectivity and discernment to avoid the danger of propping up a tottering theory with the aid of ad hoc explanations. In some respects Dr. Eysenck's views are not essentially different from those of the psychoanalysts he has criticized so vigorously and often. Thus, he holds that neuroses are neither innate nor due to subtle lesions, but the product of past experience. His view that both normal and abnormal behaviour may be described in terms of the same dimensions of personality would have been approved by Freud. Although such emphases have had the valuable effect of broadening the perspectives of clinical work and scientific inquiry in relation to mental disease, they are none the less one-sided, for they ignore the sharp discontinuities between health and disease, strongly suggesting the entry of new elements in neurotic as well as in psychotic disorders. It is these that constitute the psychiatrist's specific problem and are for him the focus of interest. The psychiatrist will look in vain in the description of the case material in these volumes for the operational definitions that governed the selection of patients or for information on whether they were in the early or late stages of an attack, in remission or relapse, subject to illnesses of long or short duration. Although Dr. Eysenck was right to push his particular approach as far as it would go in the field of abnormal psychology, his theories are without compelling quality or capable of affording to the psychiatrist, at any rate, the intellectual and aesthetic satisfactions so characteristic of fruitful new theories, even in their " weak " stage. One suspects, therefore, that it may ironically prove that Dr. Eysenck's studies have, like Freud's investigations, taught us more about those characteristics of psychiatric patients which they share with normal subjects than those in respect of which they differ from them. But his contributions, and those of his group, to the objective, scientific investigation of human behaviour are remarkable in their range and comprehensiveness and will probably prove lasting.