The Selfishness Questionnaire: Egocentric, Adaptive, and Pathological Forms of Selfishness.

Despite its importance in society, there is virtually no standardized research on the personality trait of selfishness, in part due to the absence of an assessment instrument. The central aim of this study was to develop a brief (2-3 min) self-report personality measure of selfishness with three main subtypes: egocentric, adaptive, and pathological. Questionnaires were administered to an undergraduate sample, with replicability and generalizability tested on a community population. A confirmatory factor analysis supported the existence of the three hypothesized forms of selfishness. Good internal reliability, test-retest reliability, convergent validity, discriminant validity, factorial validity, incremental validity, and criterion validity were documented. Selfishness was associated with reduced levels of mindfulness and more utilitarian decision making, whereas Tibetan Buddhist monks were less selfish than controls. Findings from the student sample were replicated in the community sample. To our knowledge, this is the first systematic examination of the personality construct of selfishness and the first instrument to assess selfishness and its variants.