Genetic and environmental influences on observed personality: evidence from the German Observational Study of Adult Twins

Previous behavior-genetic research on adult personality relied primarily on self-reports or peer reports that may be subject to contrast effects, resulting in biased estimates of genetic and environmental influences. In the German Observational Study of Adult Twins (GOSAT), personality traits of 168 monozygotic (MZ) and 132 dizygotic (DZ) twin pairs were rated on 35 adjective scales, largely markers of the Big 5. The ratings were provided by 120 judges who never met the twins but observed videotaped behaviors of 1 twin of each pair in 1 of 15 different settings. The aggregated video-based trait ratings were highly reliable, and substantial correlations were obtained between MZ as well as DZ twins. Model-fit analyses suggested about 40% genetic, 25% shared environmental, and 35% nonshared environmental influence. Extraversion was the only trait that seemed not to be influenced by shared environment.     

Modeling Rater Disagreement for ADHD: Are Parents or Teachers Biased?

The present study is the first to utilize twin modeling to examine whether parent-teacher disagreement for ADHD ratings is due to parent or teacher bias, or due to raters observing different but valid ADHD behaviors. A joint analysis was conducted with 106 twin pairs, including twins selected for ADHD and control twin pairs. Total ADHD scores were analyzed using multiple rater models that estimate genetic and environmental contributions common to both raters and unique to each rater. Results suggest that 1) disagreement in ADHD ratings is strongly due to parents and teachers observing different ADHD behaviors, some of which is valid and some of which is due to bias, and 2) parents may be more biased than teachers in their ADHD ratings.     

Shared genes, shared experiences, and similarity of personality: data from 14,288 adult Finnish co-twins

Similarities for Extraversion (E) and Neuroticism (N) scale scores from the Eysenck Personality Inventory were evaluated in 7,144 adult twin pairs, drawn from the population-based Finnish Twin Cohort, as a function of the co-twins' genetic resemblance, gender, age, and the frequency of their social interaction with each other. To separate effects of shared genes from those of shared experience, we performed hierarchical multiple regressions of double-entry data matrices. Results establish the predictive significance of both genetic and experiential influences: Genetic effects remained significant when tested after the effects of social contact were first removed; conversely, for N scores, the effects of social contact remained significant when assessed after genetic influences were first removed. These findings establish genetic variance in major dimensions of adult personality but assign a significant role to common experience as well. The first finding constructively replicates reports by others; the second challenges the widespread assumption that shared experiences have a negligible impact on sibling similarity in adult personality.     

The structure of interpersonal traits: Wiggins's circumplex and the five-factor model

Using a sample of 315 adult men and women, self-reports on Wiggins's revised Interpersonal Adjective Scales were jointly factored with self-reports, peer ratings, and spouse ratings on the NEO Personality Inventory to examine the relations between the two models. Results suggest that the interpersonal circumplex is defined by the two dimensions of Extraversion and Agreeableness, and that the circular ordering of variables is not an artifact of response biases or cognitive schemata. Circumplex and dimensional models appear to complement each other in describing the structure of personality, and both may be useful to social psychologists in understanding interpersonal behavior.     

Can children provide coherent, stable, and valid self-reports on the big five dimensions? A longitudinal study from ages 5 to 7

Research on early childhood personality has been scarce. Self-reports of Big Five personality traits were measured longitudinally with the Berkeley Puppet Interview when children were 5, 6, and 7 years of age. For comparative purposes, Big Five self-reports were collected in a sample of college students. The children's self-reports showed levels of consistency and differentiation that approached those of the college age sample. Children's personality self-reports demonstrated significant correlations across the 1- and 2-year longitudinal intervals. Substantial and increasing convergence was found between children's self-reports of Extraversion, Agreeableness, and Conscientiousness and conceptually relevant behavior ratings provided by mothers, fathers, and teachers. Children's self-reports of Neuroticism were unrelated to adults' reports but did predict sadness and anxious behavior observed in the laboratory. The results provide the beginnings of an account of how the Big Five dimensions begin to be salient and emerge as coherent, stable, and valid self-perceptions in childhood.     

Sources of Variance in Personality Facets: A Multiple‐Rater Twin Study of Self‐Peer,Peer‐Peer,and Self‐Self (Dis)Agreement

ABSTRACT This study considered the validity of the personality structure based on the Five‐Factor Model using both self‐ and peer reports on twins' NEO‐PI‐R facets. Separating common from specific genetic variance in self‐ and peer reports, this study examined genetic substance of different trait levels and rater‐specific perspectives relating to personality judgments. Data of 919 twin pairs were analyzed using a multiple‐rater twin model to disentangle genetic and environmental effects on domain‐level trait, facet‐specific trait, and rater‐specific variance. About two thirds of both the domain‐level trait variance and the facet‐specific trait variance was attributable to genetic factors. This suggests that the more personality is measured accurately, the better these measures reflect the genetic structure. Specific variance in self‐ and peer reports also showed modest to substantial genetic influence. This may indicate not only genetically influenced self‐rater biases but also substance components specific for self‐ and peer raters' perspectives on traits actually measured.     

Rater bias in the EASI temperament scales: a twin study

Under trait theory, ratings may be modeled as a function of the temperament of the child and the bias of the rater. Two linear structural equation models are described, one for mutual self- and partner ratings, and one for multiple ratings of related individuals. Application of the first model to EASI temperament data collected from spouses rating each other shows moderate agreement between raters and little rating bias. Spouse pairs agree moderately when rating their twin children, but there is significantly rater bias, with greater bias for monozygotic than for dizygotic twins. MLE's of heritability are approximately .5 for all temperament scales with no common environmental variance. Results are discussed with reference to trait validity, the person-situation debate, halo effects, and stereotyping. Questionnaire development using ratings on family members permits increased rater agreement and reduced rater bias.     

Genetic and environmental influences on pre‐schizophrenic personality: MAXCOV‐HITMAX and LISREL analyses

Postulating that the predisposition to illness in Claridge's disease model of schizophrenia can be equated with the personality dimensions S or Insensitivity, (low) E or Extraversion, and N or Neuroticism, as measured by Van Kampen's 3DPT, and assuming that the mode of transmission of schizophrenia is basically polygenic, the genetic and environmental etiology of S, E, and N was assessed in a sample of 52 MZ and 76 DZ twin pairs and their parents by means of LISREL. Besides, in a sample of 2118 subjects MAXCOV–HITMAX analyses were conducted for these factors as well as for the personality dimension G or Orderliness, but now assessed by the 4DPT, in order to find out whether a discrete or quasi‐discrete variable might also underlie these dimensions, giving support to the possibility of dominance or epistasis. The results obtained in these investigations favoured a model for all three dimensions, allowing for both additive and non‐additive genetic effects in combination with non‐shared environmental influences. It was not possible to choose between a model involving dominance and a model involving epistatic genetic effects. With the use of scores corrected for sex and age, which were converted to normal scores, the proportion of variance explained by additive genetic factors was 20% for S, 40–41% for E, and 26–29% for N. Dominance or multiple‐gene epistasis accounted for 37–38% (S), 19–20% (E), and 30–31% (N), and unshared environmental influences for 42–43% (S), 41% (E), and 42–43% (N) respectively. Copyright © 1999 John Wiley & Sons, Ltd.     

Personality characteristics of research volunteers

We evaluated Big Five personality factor differences between research volunteers and nonvolunteers. In the first study, 158 military officers were asked to participate in a mail survey. The personality scores of the officers were available from an archival data set. In our second study, adult siblings from large families were invited to participate in extensive clinical epidemiological evaluations. The personality scores of volunteers (N = 55) and nonvolunteers from the same families (N = 29) were estimated from sibling ratings made by those who participated in the study. In both studies, respondents, compared to nonrespondents, were found to be significantly lower in Neuroticism and higher in Conscientiousness. The second study further indicated respondents as being higher in Extraversion and Agreeableness. Copyright © 2007 John Wiley & Sons, Ltd.     

Age,Gender, and Self-Esteem Differences in Adolescent Coping Styles

Abstract

A self-complete inventory was used to collect data concerning consumer cognition and activity among a sample of 211 young adults. Eysenck's (1958) short personality questionnaire was incorporated into the inventory, so that the respondents could be classified by both degree of extraversion-introversion (E) and stability-neuroticism (N). The results show that, although levels of E and N were not directly related to measures of spatial cognition among the sample consumers, a statistically significant relationship was found between N and actual spatial behavior, with stable consumers tending to use relatively fewer centers. Further analysis, however, revealed that the E dimension of personality was of significance when levels of actual center usage were considered as a proportion of the total universe of known opportunities. Moreover, when the sample was disaggregated by gender, it was found that extraverted-unstable men indulged in more extensive spatial behavior in relation to known opportunities than did other personality groups.     

Genetic and environmental structure of adjectives describing the domains of the Big Five Model of personality: A nationwide US twin study

We applied multivariate models specifying genetic and environmental influences on adjectives describing each of the five personality domains specified in the Big Five Model of personality (BFM; Extraversion, Neuroticism, Agreeableness, Conscientiousness, and Openness). We selected the specific models to partition the observed covariance among the adjectives describing each domain into genetic and environmental components in order to assess the etiologic basis for each domain's phenotypic coherence. The sample on which our analyses were based was part of the National Survey of Midlife Development in the United States (MIDUS). It consisted of 315 monozygotic and 275 same-sex dizygotic twin pairs. Results revealed both common and specific genetic and environmental influences for each domain, suggesting that all of the domains are etiologically complex. Models specifying the domains as latent phenotypic constructs fit more poorly than models suggesting more complex structures for all domains except Extraversion and Neuroticism. These results raise questions about the BFM as a coherent model of genetic and environmental influences on personality or, alternatively, about the etiological unity of latent phenotypic personality trait constructs beyond Extraversion and Neuroticism.     

Sex differences in genetic and environmental effects on aggression

The aim of the present study was to investigate the genetic and environmental factors influencing teacher and parental rated aggression in boys and girls, asking whether the magnitude of these effects is similar across rater and sex. The study is part of an ongoing nationwide twin‐family study of behavioral development and health habits carried out in Finland. The sample consisted of 1651 twin pairs (264 monozygotic male, 300 monozygotic female, 292 dizygotic male, 278 dizygotic female, and 517 dizygotic opposite‐sex twin pairs), representing subsets of five 11‐ to 12‐year‐old twin cohorts (b. 1983–1987). The data were collected using the teacher and parental rating forms of the Multidimensional Peer Nomination Inventory. Structural equation models of sex‐limitation assessed sex differences in genetic and environmental influences on aggression. The results suggested significant genetic, common environmental, and specific environmental effects on aggression in both boys and girls, but the best fitting model differed depending on the informant. For both ratings, boys showed lower levels of heritability and higher levels of common environment than girls. In addition, the teacher rating data also suggested the presence of either sex‐specific common environmental effects or sex‐specific genetic effects. Support is provided also for sibling contrast effects, either at the behavioral level or as a rater bias. Aggr. Behav. 29:55–68, 2003. © 2003 Wiley‐Liss, Inc.     

Joint factors in self-reports and ratings: Neuroticism,extraversion and openness to experience

Although most dimensional theories of personality assume that the same traits can be assessed in either ratings or self-reports, joint factor analyses of data from these two methods have seldom provided clear evidence in support of this position. Previous analyses have found a preponderance of within-method factors, or have had to transform variables or use unorthodox rotational procedures in order to control the effects of method variance. The present study argues that recent conceptual and technical advances should now make it possible to show joint factors at the second-order level using standard factor techniques. The NEO Inventory and NEO Rating Form, which measure 18 traits in the domains of Neuroticism, Extraversion and Openness to Experience, were administered to a sample of 281 men and women. Varimax rotation of three principal components clearly showed the hypothesized structure within and across self-reports and spouse ratings. Convergent and discriminant validity of the joint factors with the EPI scales was also shown. The results suggest that the effects of method variance can be minimized if well-qualified raters use psychometrically adequate instruments to provide ratings of clearly conceptualized traits. In addition, they provide strong evidence for the validity of the proposed three-domain model of personality.     

Basic value orientations and moral foundations: Convergent or discriminant constructs?

This study examined the structural and genetic links between value orientations, based on the theory of basic values, and moral concerns, based on moral foundations theory. We hypothesized both structural and genetic convergence of Conservation (versus openness to change) with Binding foundations and of Self-transcendence (versus self-enhancement) with Individualizing foundations. We analyzed self- and informant ratings from 924 participants with extended multitrait-multirater modeling and ran twin model analyses on self-ratings from 555 twin pairs. For Conservation and Binding foundations, we found partial convergence across different rater perspectives and a substantial genetic overlap, but also distinct genetic factors. Self-transcendence and Individualizing foundations were found to be structurally divergent, but genetically linked. We discuss the conceptual and measurement-related implications of the findings.     

Personality in adulthood: a six-year longitudinal study of self-reports and spouse ratings on the NEO Personality Inventory

Previous longitudinal studies of personality in adulthood have been limited in the range of traits examined, have chiefly made use of self-reports, and have frequently included only men. In this study, self-reports (N = 983) and spouse ratings (N = 167) were gathered on the NEO Personality Inventory (Costa & McCrae, 1985b), which measures all five of the major dimensions of normal personality. Cross-sectional and longitudinal analyses on data from men and women aged 21 to 96 years showed evidence of small declines in Activity, Positive Emotions, and openness to Actions that might be attributed to maturation, but none of these effects was replicated in sequential analyses. The 20 other scales examined showed no consistent pattern of maturational effects. In contrast, retest stability was quite high for all five dimensions in self-reports and for the three dimensions measured at both times in spouse ratings. Comparable levels of stability were seen for men and women and for younger and older subjects. The data support the position that personality is stable after age 30.     

Happiness is a personal(ity) thing: the genetics of personality and well-being in a representative sample.

Subjective well-being is known to be related to personality traits. However, to date, nobody has examined whether personality and subjective well-being share a common genetic structure. We used a representative sample of 973 twin pairs to test the hypothesis that heritable differences in subjective well-being are entirely accounted for by the genetic architecture of the Five-Factor Model's personality domains. Results supported this model. Subjective well-being was accounted for by unique genetic influences from Neuroticism, Extraversion, and Conscientiousness, and by a common genetic factor that influenced all five personality domains in the directions of low Neuroticism and high Extraversion, Openness, Agreeableness, and Conscientiousness. These findings indicate that subjective well-being is linked to personality by common genes and that personality may form an "affective reserve" relevant to set-point maintenance and changes in set point over time.     

Acquaintanceship and self/observer agreement in personality judgment

Self/observer agreement on HEXACO-PI-R scale scores was examined as a function of observers’ subjective ratings of acquaintanceship. For each participant (N = 2199), personality self-reports were obtained along with observer reports from a friend. Each factor-level scale displayed a different pattern of upward accuracy (agreement) trends in personality judgment. Self/observer agreement for Extraversion, Emotionality, and Openness was noticeably stronger at lower acquaintanceship than that for Conscientiousness, Agreeableness, and Honesty-Humility. Conscientiousness showed a steep upward accuracy trend across acquaintanceship levels, reaching a level of accuracy comparable to that of Extraversion and Emotionality. Self/observer agreement for Honesty-Humility and Agreeableness showed slower upward trends than that of Conscientiousness. In several cases, facet-level traits within the same broad factor differed in their accuracy trends.     

Rater biases in genetically informative research designs: comment on Bartels, Boomsma, Hudziak, van Beijsterveldt, and van den Oord (2007)

Rater biases are of interest to behavior genetic researchers, who often use ratings data as a basis for studying heritability. Inclusion of multiple raters for each sibling pair (M. Bartels, D. I. Boomsma, J. J. Hudziak, T. C. E. M. van Beijsterveldt, & E. J. C. G. van den Oord, see record 2007-18729-006) is a promising strategy for controlling bias variance and may yield information about sources of bias in heritability studies. D. A. Kenny's (2004) PERSON model is presented as a framework for understanding determinants of rating reliability and validity. Empirical findings on rater bias in other contexts provide a starting point for addressing the impact of rater-unique perceptions in heritability studies. However, heritability studies use distinctive rating designs that may accentuate some sources of bias, such as rater communication and contrast effects, which warrant further study.     

What is the central feature of extraversion? Social attention versus reward sensitivity

R. E. Lucas, E. Diener, A. Grob, E. M. Suh, and L. Shao (2000) recently argued that the core of the personality dimension of Extraversion is not sociability but a construct called reward sensitivity. This article accepts their argument that the mere preference for social interaction is not the central element of Extraversion. However, it claims that the real core of the Extraversion factor is the tendency to behave in ways that attract social attention. Data from a sample of 200 respondents were used to test the 2 hypotheses with comparisons of measures of reward sensitivity and social attention in terms of their saturation with the common variance of Extraversion measures. The results clearly showed that social attention, not reward sensitivity, represents the central feature of Extraversion.     

“… And How About Now?”: Effects of Item Redundancy on Contextualized Self‐Reports of Personality

A common method of studying cross-situational variation in personality involves asking people to describe their behavior in several different contexts. Although this approach is intuitively appealing, it introduces a great deal of redundancy into the measurement process and may affect the interpretation of contextualized self-reports. Specifically, when participants are asked the same questions repeatedly in a single questionnaire, they may be compelled to focus on how their behavior is different. We tested this hypothesis by experimentally manipulating the number of contexts that were included in a measure of role-related personality. In 2 experiments (Study 1 N=377, Study 2 N=524), we found that multiple-role questionnaires produced greater variation in trait levels across roles, larger differences between general and role-specific ratings, and weaker correlations between general and role-specific ratings than single-role questionnaires. These findings illustrate how the measurement process can have an effect on the variability of responses to contextualized self-reports.