The manipulation of stimulus significance, by instructions from the experimenter, may be taken as an example of verbal conditioning. Consideration of such a mechanism suggested that personality effects previously found in conditioning studies should be apparent in instructional manipulations of significance in a study of the orienting response (OR) to words. Because of recent changes in dimensioning of the personality structure, some of the items originally used to define Eysenck's extraversion (E) dimension are now used to assess the new dimension of psychoticism (P), suggesting that at least some of the established effects of E upon conditioning may be associated now with P. Hence the P scale was focused on in this study. Words differing on the evaluative dimension of the semantic differential were presented in three blocks, the first under indifferent instructions, the second under instructions to rate the words for their affective impact, and the third under indifferent instructions again. These blocks correspond to baseline, conditioning, and extinction conditions respectively. Electrodermal activity indicated enhanced conditioning, together with greater carry-over effects in the extinction phase, for low-P compared with high-P subjects. The results indicate the importance of personality effects in studies of stimulus significance and illustrate the value of the verbal conditioning mechanism in this area of the OR field. They also suggest the need to re-examine previously obtained E-effects in conditioning studies in light of changing personality tests. © 1988 Springer.