The Role of Executive Functioning and Borderline Personality Disorder Symptomatology in the Relationship Between Identity Formation and Interpersonal Functioning

Abstract

Identity formation is the core developmental task of adolescence, although not all adolescents face this task in the same way. Adolescents with an informational identity style tend to actively seek out self-relevant information, adolescents with a normative identity style tend to passively adopt values from significant others, and those with a diffuse-avoidant identity style postpone identity formation. Research suggests these identity styles differ with respect to interpersonal functioning, with the informational – and to a lesser extent normative – identity style associated with increased psychological well-being and diffuse-avoidant identity style associated with psychological maladjustment (e.g., Borderline Personality Disorder [BPD]). However, there have been no investigations into potential moderators of the relation between identity style and interpersonal problems. The current study examined how interpersonal functioning, executive functioning, and BPD symptomatology varied as a function of identity style as well as the roles of (a) executive functioning, both basic executive functions (e.g., attention, memory) and fluid intelligence (abstract reasoning, problem-solving, planning) and (b) BPD symptomatology in moderating the relation between identity style and interpersonal functioning. The study was completed in two phases. Participants in Phase I (N = 1936) completed self-report measures of the aforementioned constructs. A sub-sample of participants (n = 71) with high or low BPD symptomatology also completed neurocognitive assessments of fluid intelligence and basic executive functions (Phase II). Results indicated identity style groups differed on interpersonal functioning, BPD symptomatology, and basic executive functioning but not fluid intelligence. The high and low BPD symptom groups also differed on interpersonal functioning but not fluid intelligence. Results also indicate a diffuse-avoidant identity style (vs. informational or normative) predicted greater interpersonal problems. Additionally, basic executive functioning moderated this relationship such that it was strengthened for the informational identity style at low (vs. diffuse-avoidant or normative) and average (vs. diffuse-avoidant) basic executive functioning ability. BPD symptomatology also moderated this relationship such that it was strengthened for normative identity style (vs. diffuse-avoidant) at low and average BPD symptomatology. Fluid intelligence did not moderate this relationship. The current study provides further evidence for the differential relationship between the identity styles and interpersonal functioning and suggests that BPD symptomatology and basic executive functioning, but not fluid intelligence, moderates this relationship. Treatment considerations and directions for future research are also discussed.