Supplementary data for the paper 'Acceptance of conditionally automated cars: Just one factor?'

Recent research suggests the existence of a general acceptance factor (GAF), similar to the “big one” in personality research or the general intelligence factor (<em>g</em>). The current study, written in the form of a short commentary, sought empirical support for the GAF by using data from a large multinational questionnaire of the L3Pilot project on the acceptance of conditionally automated cars (CACs). Our analysis provides clear support for a GAF of CACs, as this factor explained 55% of the variance among the questionnaire items. Criterion validity was established by demonstrating an inverted U-curve between GAF scores and respondents’ ages in 17 countries. It is recommended that researchers concerned with technology acceptance consider whether their acceptance constructs are sufficiently unique or merely part of a positive manifold.