Immune power personality is a term coined by H. Dreher to describe 7 personality traits which had previously been found in empirical research to be associated with better functioning of some aspects of the immune system. These traits included the ACE (attend-connect-express) factor, the capacity to confide, assertiveness, healthy helping, the affiliative trust, hardiness, self-complexity. The objective of this study was to operationalize the concept of the immune power personality in the form of a psychometrical questionnaire.

Literature analysis was applied to elicit the psychological contents of the immune power personality traits. For each trait, initial pools (from 36 to 50) of items were generated. Four consecutive studies were carried out in order to select psychometrically most suitable items for the final version of the instrument.

Item properties were calculated and, at each stage of the study, items with insufficient psychometric properties were eliminated to yield, finally, 6 items for each trait. As some traits were found to be highly correlated with social desirability, the control subscale was developed and introduced into the instrument in order to control the effect of excessively positive self-presentation. Reliability coefficients for each trait were found to be high. Exploratory factor analysis yielded a six-factor solution for the questionnaire, with the vast majority of the items loading highest on the pre-assumed subscales. The items measuring the ACE trait were diffused within other factors.

Immune Power Personality Questionnaire seems a promising psychometric tool which may enhance future research on the personality-health relationships.