A Behavioral Genetic Analysis of Callous-Unemotional Traits and Big Five Personality in Adolescence APPROVED BY SUPERVISING COMMITTEE:

Callous-unemotional (CU) traits, such as lacking empathy and emotional insensitivity, predict the onset, severity and persistence of antisocial behavior. CU traits are heritable, and genetic influences on CU traits contribute to antisocial behavior. This study examines genetic overlap between CU traits and general domains of personality. We measured CU traits using the Inventory of Callous and Unemotional Traits (ICU) and Big Five personality using the Big Five Inventory (BFI) in a sample of adolescent twins from the Texas Twin Project. Results indicate that genetic influences on the Big Five personality dimensions account for the entirety of genetic influences on CU traits. This finding suggests that the BFI and ICU measure the same genetic trait dimensions. Nevertheless, Item Response Theory results indicate that the ICU is more sensitive when measuring clinically relevant personality variation at the lower extremes of personality trait continua, particularly low agreeableness and low conscientiousness. Results of the current study suggest that understanding the development of normal personality may inform an understanding of the genetic underpinnings of callous and unemotional behavior.