The genetic and environmental relationship between Cloninger‘s dimensions of temperament and characterIntroductionObjectiveMethodSubjectsMeasuresStatistical analysisAnalysis of raw ordinal dataGenetic analysisMultivariate analysesResultsTests of threshold homogeneityPolychoric correlationsTwin pair correlationsCorrelation contrastsUnivariate analysisMultivariate analysisDiscussionUnivariateMultivariateAcknowledgementsReferencesThe genetic and environmental relationship betweenCloninger’s dimensions of temperament and characterNathan A. Gillespiea,*, C. Robert Cloningerb, Andrew C. Heathc,Nicholas G. MartinaaQueensland Institute of Medical Research, Brisbane, AustraliabCentre for Psychobiology of Personality, Washington University, St Louis, Missouri, USAcMissouri Alcohol Research Centre, Department of Psychiatry, Washington University School of Medicine,St Louis, Missouri, USAReceived 11 March 2002; received in revised form 18 November 2002; accepted 30 December 2002AbstractThe purpose of this study was to determine whether Cloninger’s revised 7-factor model of personalityshowed incremental validity over his four dimensions of temperament. A sample of 2517 Australian twinsaged over 50 between 1993 and 1995 returned completed self-reported measures of Self-directedness,Cooperativeness, and Self-transcendence from Cloninger’s Temperament and Character Inventory. Manyof these twins had participated in a 1988 study containing Cloninger’s temperament measures of HarmAvoidance, Novelty Seeking, Reward Dependence and Persistence. Contrary to theoretical expectations,univariate analyses revealed that familial aggregation for the character dimensions could be entirelyexplained by additive gene action alone. Although temperament explained 26, 37 and 10% of additivegenetic variance in Self-directedness, Cooperativeness and Self-transcendence, respectively, seven geneticfactors were required to explain the genetic variance among the TPQ dimensions, and almost all of thenon-shared environmental variance was unique to each dimension of character. Our results indicate thatthe inclusion of all seven dimensions in a taxonomy of personality is warranted.# 2003 Elsevier Ltd. All rights reserved.Keywords: Personality; Cloninger; Temperament; Character; Genes; Twins1. IntroductionCloninger’s theory of personality is based on a synthesis of information from family studies,studies of longitudinal development, and psychometric studies of personality structure, as well as0191-8869/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.doi:10.1016/S0191-8869(03)00042-4Personality and Individual Differences 35 (2003) 1931–1946www.elsevier.com/locate/paid* Corresponding author at: Genetic Epidemiology Unit, Queensland Institute of Medical Research, Post Office, RoyalBrisbane Hospital, 300 Herston Road, Herston, Qld 4029, Australia. Tel.: +61-7-3362-0228; fax: +61-7-3362-0101.E-mail address: [email protected] (N.A. Gillespie).neuropharmacologic and neuroanatomical studies of behavioral conditioning and learning inman and animals (Cloninger, 1987). His revised biosocial model of personality posits sevendomains of personality as measured by the Temperament and Character Inventory (TCI)(Cloninger, 1994): four temperament (Harm Avoidance, Novelty Seeking, Reward Dependenceand Persistence) and three character domains (Self-Directedness, Cooperativeness, and Self-Transcendence) (Cloninger, 1994).Originally, the model included only three dimensions of temperament; Harm Avoidance,Novelty Seeking, and Reward Dependence as measured by the 100 item self-report Tri-Dimen-sional Personality Questionnaire (TPQ) (Cloninger, 1986). The Persistence items in RewardDependence were later separated and recognised as a fourth, separately inherited dimension ofpersonality (Cloninger, 1994; Stallings, Hewitt, Cloninger, Heath, & Eaves, 1996). Temperamentwas conceptualised as corresponding to heritable biases in memory processing involved in pre-semantic perceptual processing and encoding of concrete visuospatial structural information andaffective valence. These processes were hypothesized to be functionally organized as indepen-dently varying brain systems aligned to specific monoaminergic cell bodies which in turn areresponsible for autonomic responses involved in the activation, maintenance and inhibition ofbehaviour (such as differences in classical conditioning, operant conditioning and non-associativelearning, i.e. sensitization and habituation) (Cloninger, 1994). These dimensions were intended toprovide differential diagnosis within personality disorder (PD) populations, with combinations ofextreme variants in the four basic dimensions corresponding to traditional PD taxonomy (Clo-ninger, 1987). Cloninger has subsequently argued that a major limitation of temperament profilesis that they are not diagnosis specific because variation in these continuous trait measures doesnot distinguish clinical from non-clinical populations. Additional aspects of personality weretherefore required to enable such distinctions.Accordingly, the model was revised (Cloninger, Svrakic, & Przybeck, 1993) to include threedimensions of character: Self-directedness, Cooperativeness and Self-transcendence. Thesedimensions were based on a synthesis of information about social and cognitive development anddescriptions of personality development in humanistic and transpersonal psychology (Cloninger,1994; Cloninger et al., 1993). Specifically, the scales were designed to measure conceptual memorybiases involved in the processing or conversion of sensory input into abstract symbols whichtranslate into concepts of personal, social and universal identity. Self-directedness measuresindividual self-acceptance, Cooperativeness measures acceptance of other people, while Self-transcendence captures the degree to which an individual feels a part of nature and the universe atlarge. These dimensions were derived from factor analyses of childhood personality inventories(Sigvardsson, Bohman, & Cloninger, 1987) as well as from investigation of items from the NEOPersonality Inventory, Multidimensional Personality Questionnaire, Profile of Mood States, andMinnesota Multiphasic Psychological Inventory which identified additional dimensions of per-sonality uncorrelated with Cloninger’s temperament dimensions. According to the model, indi-viduals with mature personalities are described as self-reliant, cooperative, and