A novel visual illusion paradigm provides evidence for a general factor of illusion sensitivity and personality correlates

Abstract

Visual illusions are a gateway to understand how we construct our experience of reality. Unfortunately, important questions remain open, such as the hypothesis of a common factor underlying the sensitivity to different types of illusions, as well as of personality correlates of illusion sensitivity. In this study, we used a novel parametric framework for visual illusions to generate 10 different classic illusions (Delboeuf, Ebbinghaus, Rod and Frame, Vertical-Horizontal, Zöllner, White, Müller-Lyer, Ponzo, Poggendorff, Contrast) varying in strength, embedded in a perceptual discrimination task. We tested the objective effect of the illusions on errors and response times, and extracted participant-level performance scores (n=250) for each illusion. Our results provide evidence in favour of a general factor underlying the sensitivity to different illusions (labelled Factor i). Moreover, we report a positive link between illusion sensitivity and personality traits such as Agreeableness, Honesty-Humility, and negative relationships with Psychoticism, Antagonism, Disinhibition, and Negative Affect.

Individual Differences in Visual Illusions: Graphical and Analytic Approaches For Finding Structure in Real-World Cases

“…In fact, cognitive abilities often yield positive correlations, a concept known as Spearman's positive manifold (Ritchie, 2015). In keeping with the trend found in studies of cognition, Makowski et al (2023) have indeed found a general factor underlying perceptual illusion. Moreover, they claim this general susceptibility factor is positively related to positive personality traits (such as agreeableness) and negatively related to dark-triad personality traits.…”

“…The first is that individual differences in visual illusions are at best weakly correlated (Cretenoud et al, 2019) and the proportion of variance accounted for any illusion on any other is surprisingly small. The second is that individual differences are related by a common factor which may even reflect personality differences (Makowski et al, 2023). We find support for both positions.…”

“…Moreover, because this variation is small and loads on all tasks, it may have little to do with illusions per se. An alternative is that the factor relates to how people engage in computer tasks or how conscientious they are (Makowski et al, 2023).…”