The Eysenck personality scales: stability and change after therapy.

Eysenck has linked personality theory with the aetiology and treatment of abnormal behaviour (Eysenck, 1970). At least four levels of explanation link hypothetical neurophysiological mechanisms to self-report measures of personality, laboratory task performance and observed social habits and attitudes (Eysenck, 1960). The phenomena of neurotic breakdown and recovery provide one natural test of predictions from personality theory with respect to neuroticism (N) and extraversion (E). Taking phobias as an example, it is predicted that persons with a high score on N (a low threshold for emotional activation) develop phobic reactions more readily, and the more introverted the person, the more quickly and strongly are the phobic reactions acquired and lastingly maintained (Eysenck and Rachman, 1965, p. 36).In a prospective study of university students. Kelvin et al. (1965) were unable to find a relationship between initial N score and psychological distress up to 2.5 years later. Rather, the N scale appeared to reflect current mental status, increasing when distress was reported. E scores also dropped in a group of students who happened to be referred to a psychiatrist. Similarly, in a 3-year follow-up of patients who had attended a psychiatrist. Ingham (1966) found that change in clinical status was reflected in a change of N, with the score of the improved group returning to the population mean. Initial personality did not predict change in clinical status. It was also found in a number of analyses that improvement was related to an increase in extraversion.The present study was designed to replicate Ingham's experiment on a more homogeneous group of neurotic patients—all phobic—who had received fantasy or in vivo exposure treatment (Marks, 1974). This treatment can be compared to an extinction procedure, i.e. the non-reinforced presentation of the CS, and should therefore provide a good testing ground of personality theory. Eysenck's theory predicts that the speed and success of treatment will be related to initial E and N scores. In particular, the speed of extinction of the neurotic fear should be related to extraversion; the more extraverted the patient the more rapidly should the fear extinguish.