Wright, Zara2019-03-132019-03-132016-12https://hdl.handle.net/11299/202065University of Minnesota M.A. thesis. 2016. Major: Psychology. Advisor: Robert Krueger. 1 computer file (PDF); 47 pages.The Diagnostic and Statistical Manual for Mental Disorders, 5th Edition (DSM-5) proposes an alternative model for personality disorders, a key element of which is pathological traits. These traits can be operationalized by the Personality Inventory for the DSM-5 (PID-5). Although there has been extensive research on genetic and environmental influences on normative personality, the heritability of the DSM-5 traits, and maladaptive personality in general, remains understudied. The present study addresses this gap in the literature by assessing traits indexed by the PID-5 and the International Personality Item Pool NEO (IPIP-NEO) in adult twins (N = 1,812 individuals). Research aims included 1) replicating past findings of heritability of normative personality as measured by the IPIP-NEO as a benchmark for studying maladaptive traits, 2) ascertaining univariate heritability estimates of maladaptive personality traits as measured by the PID-5, 3) establishing how much variation in maladaptive personality can be attributed to the same genetic components affecting variation in normative personality, and 4) determining residual variance in maladaptive personality after variance attributable to genetic and environmental components of normative personality has been removed. Results revealed that maladaptive personality traits reflect similar levels of heritability to that of normative personality. Further, maladaptive and normative personality traits that correlate at the phenotypic level also correlate at the genotypic level, indicating overlapping genetic components contribute to variance in both. Nevertheless, we also found evidence for genetic and environmental components unique to maladaptive personality traits, not shared with normative personality.enbehavior geneticsCholeskyheritabilitymaladaptive personalityNEOPID-5Thesis or Dissertation