Primary and secondary suggestibility; an experimental and statistical study.

Introduction.—The concept of 'suggestibility' is of obvious importance to social as well as to abnormal psychology; it has long been used as an explanatory concept in both these spheres. Yet the evidence regarding the question as to whether or not we have the right to speak of 'suggestibility' at all, i.e., whether this term covers a simple, unitary mental trait, or whether it would be more accurate to speak of' suggestibilities,' is very far from complete. The question of generality or specificity is still unsettled. Averling and Hargreaves, in discussing their experimental findings, "consider that . . . the most probable explanation of [the] results is . . . the existence of a general factor of suggestibility, combined with group factors common to two or more tests" (3, p. 73). Similarly, Otis (24) believes in the existence of a general trait of 'ability to resist suggestion,' a belief also based on experimental evidence. Brown (9), on the other hand, found little evidence of such generality in his pioneer studies, and Estabrooks (11) also had to report that the majority of correlations found by him were around zero. Allport (1) believes that suggestibility is a trait which may characterize a few people consistently, but that it is not otherwise a 'unitary' trait, while Britt (8) also is sceptical with regard to the existence of a general trait of this nature. Many investigators believe in the existence of different types of suggestibility, and many schemes of such typological division have been worked out by Prideaux (25) and later writers. Thus, Hull distinguishes prestige and non-prestige suggestion, identifying the first-named with that found in his Body-Sway test, and the latter with the Binet Progressive Weights and Progressive Lines tests (19). Murphy et al. discuss three common pyschological principles underlying many 'suggestion' tests (23). Bird (6) speaks of direct and indirect suggestibility. In a factorial study of eight tests of suggestibility, Eysenck (12) found no evidence of a general factor running through all the tests 1 With the support of the Rockefeller Foundation. We are also indebted to the Superintendent of Mill Hill Emergency Hospital for permission to use the clinical material there.