Personality Pathology and Interpersonal Dysfunction Within Family, Parent-Child, and Romantic Relationships: Monozygotic Co-Twin Control Analysis

• In Event: Poster Session 09
  In Poster Session: PS 09 Topic - Parenting & Parent-Child Relationships

Abstract

A new alternative model for personality disorders was added to the most recent version of the Diagnostic and Statistical Manual of Mental Disorder-Fifth Edition (DSM–5). In this model, individual variation in personality pathology is conceptualized using five higher-order maladaptive personality traits, Negative Affectivity, Detachment, Antagonism, Disinhibition, and Psychoticism. Maladaptive personality traits, measured using the Personality Inventory of DSM-5 (PID-5; Krueger Derringer, Markon, Watson, & Skodol, 2012), have been found to be generally associated with interpersonal dysfunction, particularly in the romantic relationship domain. However, more specific aspects of the nature of this dysfunction in other important relationship domains, such as the larger family and parent-child relationship, have yet to be examined. In the present study, we examined associations between adult maladaptive personality traits and functioning in the family, parent-child, and romantic relationship domains, assessed using multiple reporters, in a sample of twin mothers (N = 106; 100% monozygotic) and their 7- to 13-year-old children (N = 176). We expected that mother maladaptive personality traits would be generally associated with lower family cohesion, poorer parent-child relationship quality and lower mother romantic satisfaction. We also hypothesized that the mother report would yield stronger associations with the PID-5 traits compared to the child report. Results showed that greater mother Detachment and Psychoticism were associated with significantly lower family cohesion, as reported by both mothers and their children. Greater mother Disinhibition and Psychoticism was associated with significantly poorer-quality parent-child relationship, as reported by mothers, but not by their children. Greater mother Negative Affectivity, Detachment, Disinhibition, and Psychoticism, but not Antagonism, was associated with significantly lower romantic relationship satisfaction. Next, we extended beyond these usual cross-sectional correlational analyses by taking advantage of the “naturally” occurring quasi-experimental aspect of our twin sample (McGue, Osler, & Christensen, 2010; Rutter, 2007). We conducted co-twin control analyses to isolate potential twin difference effects on interpersonal functioning. The results of the co-twin analyses demonstrated several significant twin difference effects. Twin mothers with greater Detachment reported poorer-quality family cohesion than their co-twins will lower Detachment, consistent with a causal effect on functioning in the family relationship domain. Twin mothers with greater Detachment, Disinhibition, and Psychoticism reported lower romantic relationship satisfaction than their co-twins with lower Detachment, Disinhibition, and Psychoticism, consistent with causal effects on functioning in the romantic relationship domain. Taken together, these results suggest both general and specific negative associations between the five higher-order PID-5 traits and family, parent-child, and romantic relationship quality. Because the co-twin control analysis allows us to account for shared familial (genetic and environmental) factors that may act as liabilities towards interpersonal dysfunction, the results lend support to the conclusion that personality pathology may be causally associated with functioning in important domains, including in the family and romantic relationships.

Authors

• Allison Dai, University of Minnesota - Twin Cities
  Presenting Author

• Paul Caldo, University of Minnesota - Twin Cities
  Non-Presenting Author

• Kathleen M. Thomas, University of Minnesota - Twin Cities
  Non-Presenting Author

• Matt McGue, University of Minnesota
  Non-Presenting Author

• William G Iacono, University of Minnesota
  Non-Presenting Author

• SYLIA WILSON, University of Minnesota - Twin Cities
  Non-Presenting Author