A multi-faceted approach to the study of the relationship between self-esteem and the self-prioritization effect

A key aspect of self-referential processing is that self-related stimuli tend to receive preferential processing in several cognitive domains. The so-called matching task has been introduced to quantify this bias by means of arbitrary self-other associations, aimed to minimize potential confounds related to stimulus familiarity. In this paradigm, participants learn associations between neutral shapes and social labels (e.g., self vs. stranger) and then perform a perceptual matching task. The self-prioritization effect (SPE) refers to the observation that participants are faster and more accurate in self-matching trials compared to matching trials concerning the "other". Whether individual differences in implicit and explicit self-esteem can modulate the magnitude of the SPE is still a matter of debate. The present study aimed to address this question. Using a longitudinal design to assess the temporal stability of the effects, participants completed the Self-Esteem Implicit Association Test and the Name Letter Test as measures of implicit self-esteem, and the Rosenberg Self-Esteem Scale (RSES) as a measure of explicit self-esteem, alongside the matching task. The results confirmed the reliability of the SPE over time. Furthermore, unlike measures of implicit self-esteem, explicit self-esteem showed significant positive correlations with the SPE, with RSES scores being able to predict the magnitude of the SPE. Importantly, these associations were observed both within the same testing session and between sessions. These findings suggest that explicit self-evaluation is associated with the magnitude of self-prioritization. The possible implications of this pattern for theoretical accounts of self-referential processing are discussed.