Applying the Mentalization Theory to the Dimensional Trait Model of Maladaptive Personality

The mentalization model posits interpersonal difficulties and maladaptive personality traits develop as a result of an insecure attachment pattern with one’s caregiver, as well as corresponding deficits in mentalizing (i.e., the ability to understand others’ and one’s own mental states). This model has been theorized as the basis for Cluster B personality disorders (PDs), and a large body of research has provided evidence supporting associations between insecure attachment, mentalizing, and Cluster B PDs. Nevertheless, developments in the personality field have indicated a dimensional representation of pathological traits is needed, particularly in accordance with the DSM-5’s alternative model of PDs. Despite evidence linking the mentalization model to PDs, this model has yet to be applied to dimensional maladaptive personality traits. This study sought to fill this gap and examine links between constructs of the mentalization model and maladaptive personality domains in a sample of 338 undergraduates. Five maladaptive personality domains were examined as dependent variables; attachment dependence, attachment avoidance, and overall mentalizing ability were entered as independent variables; and interaction terms between mentalizing and each attachment dimension were explored as moderators. Results indicated overall mentalizing moderated the relation between attachment avoidance and Negative Affectivity. Additionally, posthoc analyses revealed moderating effects of overall mentalizing on the relations between attachment avoidance and the Emotional Lability, Hostility, and Perseveration trait facets. These results support the mentalization model’s application to the alternative model of PDs, particularly in relation to the links between negative affectivity and Cluster B PDs, and encourage future research into dimensional personality