Some personality traits converge gradually by long-term partnership through the lifecourse--genetic and environmental structure of Cloninger's temperament and character dimensions.
Temperament and Character Inventory (TCI) is a comprehensive personality inventory that is widely used in behavioral genetics. The original theory suggested that temperament traits were under genetic influences, whereas character traits were gradually built by an interaction between temperaments and environment until early adulthood. This study attempted to evaluate TCI by examining the genetic and environmental contributions to personality with particular attention to spousal effects. From 687 families, a total of 3459 Korean adult individuals completed the survey. Among them, there were 542 Monozygotic (MZ) twin pairs and 122 Dizygotic twin pairs. Intraclass correlation coefficients (ICCs) and heritability were calculated to examine the genetic and shared environmental contributions to personality. Moderate genetic contributions (0.17-0.43) were found for all TCI traits along with the evidence of shared environment (0.11-0.31) for harm avoidance (HA) and all characters. The ICCs of TCI in MZ pairs ranged 0.36-0.46. Spouses' had little resemblance for temperament, whereas for character dimensions, spouses (0.27-0.38) were more similar than first degree relatives (0.10-0.29). Resemblance between spouses increased with duration of marriage for most characters and HA. When the growing similarities between spouses were compared with their MZ cotwins' for subgroup of 81 trios, self-directedness (SD) of character showed even more similarities toward their spouses than cotwins as partnership duration increased (r = 0.32). Our findings with regard to change in SD into late adulthood support the psychobiological theory of temperament and character, which suggests that both personality domains have distinct developmental trajectories despite equally large genetic influences.
Complex Disease & Genome Epidemiology Branch, Department of Epidemiology, School of Public Health, Seoul National University, Korea. Electronic address: sarahyang@snu.ac.kr.
Sarah
S
Yang
Complex Disease & Genome Epidemiology Branch, Department of Epidemiology, School of Public Health, Seoul National University, Korea; Institute of Environment and Health, Seoul National University, Korea. Electronic address: jsung@snu.ac.kr.
Joohon
J
Sung
Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea. Electronic address: jihaekim@skku.edu.
Ji-Hae
JH
Kim
Department of Family Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea. Electronic address: yunmisong@skku.edu.
Yun-Mi
YM
Song
Department of Family Medicine, Busan Paik Hospital, Inje University College of Medicine, Korea. Electronic address: fmlky@inje.ac.kr.
Kayoung
K
Lee
Department of Biochemistry, School of Medicine, Ewha Womans University, Korea. Electronic address: 147942@hanmail.net.
Han-Na
HN
Kim
Department of Biochemistry, School of Medicine, Ewha Womans University, Korea. Electronic address: hyung@ewha.ac.kr.
Hyung-Lae
HL
Kim
Departments of Psychiatry, Genetics, & Psychology, Washington University, St. Louis, MO, USA. Electronic address: clon@wustl.edu.
C Robert
CR
Cloninger
D000328:Adult; D002605:Character; D004777:Environment; D005260:Female; D059647:Gene-Environment Interaction; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010551:Personality / Q000235:genetics*; D010555:Personality Inventory; D013694:Temperament; D014427:Twins
Heritability; Personality; Temperament and character inventory; Twin-family study