Self-enhancement and devaluation of others during belief formation are linked to narcissistic traits

Background: Narcissistic personality traits are associated with the tendency to maintain a grandiose self-image through self-enhancement and devaluation of others. Using computational modeling, we investigated how narcissistic traits and the experience of pride are linked to how individuals form beliefs about themselves and others. Methods: Healthy individuals and individuals with psychiatric diagnoses varying in narcissistic traits (N = 97) completed a learning task in which self-serving biases emerged implicitly through trial-by-trial belief updating in response to manipulated feedback. Computational modeling quantified how participants updated beliefs about their own and another person's abilities in response to better- and worse-than-expected performance feedback. Results: Higher narcissistic traits were associated with reduced learning from worse-than-expected self-related feedback, consistent with self-enhancement as a mechanism for maintaining a grandiose self-image. Individuals with higher narcissistic traits also reported greater pride following better-than-expected self-related feedback, which mediated the association between narcissistic traits and positive self-related learning. Furthermore, higher narcissistic traits were, mediated via pride, linked to increased learning from worse-than-expected feedback about the other person, suggesting that devaluing others relative to oneself may serve as a secondary pathway for maintaining a grandiose self-image. Discussion: These findings identify computational and affective mechanisms through which narcissistic traits are linked to self- and other-related belief formation. Reduced integration of negative self-related feedback together with enhanced pride following positive feedback may support grandiose self-beliefs, while enhanced learning from negative information about others suggests that individuals with higher narcissistic traits implicitly construct themselves as superior through both self-enhancement and devaluation of others during interpersonal belief formation.