Do people have control over the decisions they make? Psychometric properties of the Italian version of the free will and scientific determinism questionnaire (FAD-plus-I)

Abstract

AbstractThe FAD-Plus is a multidimensional measure of lay Beliefs in Free Will, Fatalistic Determinism, Scientific Determinism, and Unpredictability. This study had four aims: First, to test the factor structure of the Italian translation of the FAD-Plus in a sample of adults from the community, using structural equation modeling. Second, to test the reliability of the four scales. Third, to investigate gender invariance in item thresholds and factor loadings. Fourth, to analyze the criterion-related validity of the measure. Participants were 328 adults from the community, specifically 173 females and 155 males aged 18–56 years. Results showed that the proposed bifactor model tested by means of exploratory structural equation modeling fitted the data well (CFI = 1.000, RMSEA = 0.000, SRMR = 0.045), and that all the scales were reliable (Omega = .91–.98). Gender invariance was established, with no significant differences in fit indices between females and males. Beliefs in Free Will correlated positively and lowly to moderately with Aggressiveness (rs = .12), Extraversion (.25), Self- (.40) and Other-Representations of adult attachment (.43). Beliefs in Fatalistic Determinism correlated positively and lowly with Other-Representations (rs = .11), whereas its correlations with Aggressiveness, Extraversion, and Neuroticism were close to zero. In conclusion, these findings provide researchers and practitioners with evidence on a reliable and valid measure of Beliefs in free will and determinism in the Italian context, considered as predictors of individuals’ autonomy, effective coping, and prosocial behavior, of foremost importance for prevention and intervention in the community, particularly in occupational, legal, and clinical settings.