The FAD–Plus: Measuring Lay Beliefs Regarding Free Will and Related Constructs

Abstract

We describe the development of FAD–Plus, a 27-item measure of lay beliefs in free will and 3 closely related constructs: scientific determinism, fatalistic determinism, and unpredictability. Previously published measures included only a subset of these variables and tended to assume an a priori pattern of relations among these 4 beliefs. In Study 1, exploratory factor analyses suggested relatively independent factors. This independence was sustained in Study 2, using a confirmatory analysis. Each of the 4 subscales (Free Will, Scientific Determinism, Fatalistic Determinism, and Unpredictability) showed acceptable internal consistencies. Study 2 also mapped out associations with the Big Five personality traits and showed that believing in free will is not synonymous with having an internal locus of control. Study 3 replicated the instrument's structure and subscale reliabilities in a community sample. Preliminary applications are described.

Notes

¹The “FAD” portion of the label was retained to be consistent with its predecessor FAD–4: The “Plus” was added to signify that the instrument measures more than free will and determinism.

²Another alternative was to use the same content as the pro-trait items but negate them with qualifiers such as not and never. It is well known, however, that negations are less reliable and less valid because they are processed less effectively than affirmations (Holden et al., 1985; Paulhus & Vazire, 2007).

³As Lee and Ashton (2007) pointed out, interpretability is an essential criterion.

⁴Unless otherwise indicated, all significance tests are two-tailed.

⁵A more detailed account of the evolution of the FAD–Plus from its unpublished predecessor, the FAD–4, can be found online at www.psych.ubc.ca/~dpaulhus/FAD_info/.