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

Faking Good on Self-Reports Versus Informant-Reports of Emotional Intelligence

Research demonstrates that people can fake on self-rated emotional intelligence scales. As yet, no studies have investigated whether informants (where a knowledgeable informant rates a target's emotional intelligence) can also fake on emotional intelligence inventories. This study compares mean score differences for a simulated job selection versus a standard instructed set for both self-ratings and informant-ratings on the Trait Emotional Intelligence Questionnaire-Short Form (TEIQue-SF). In a 2 × 2 between-person design, participants (N = 81 community volunteers, 151 university students) completed the TEIQue-SF as either self-report or informant-report in one of two instruction conditions (answer honestly, job simulation). Both self-reports (d = 1.47) and informant-reports (d = 1.56) were significantly higher for job simulation than "answer honestly" instructions, indicating substantial faking. We conclude that people can fake emotional intelligence for both themselves (self-report) and on behalf of someone else (informant-report). We discuss the relevance of our findings for self- and informant-report assessment in applied contexts.

Association between dopamine receptor D2 Taq IA gene polymorphism (rs1800497) and personality traits

Objective

This study aimed to find a potential association between the DRD2 Taq1A gene polymorphism (rs1800497 C32806T) and personality traits.

Methods

In all, 249 youths were recruited for this study. The Short-form Revised Eysenck Personality Questionnaire was administered to assess personality traits. The participants were genotyped for the DRD2 Taq1A polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. Statistical analysis was carried out to find a possible association between the genotypes and aspects of personality traits assessed.

Results

The frequencies of the A1 and A2 alleles in our sampled population were 215 (43.2%) and 283 (56.8%), while the frequencies of A1A1, A1A2, and A2A2 were 67 (26.9%), 81 (32.5%), and 101 (40.6%), respectively. The study population was not in Hardy-Weinberg equilibrium (χ2 = 17.64, p < 0.001). The A2 allele was significantly associated with extraversion. Although this allele was also associated with neuroticism, psychoticism, and lie, the association was not significant.

Conclusion

The A2 allele of the DRD2 Taq1A polymorphism was found to be more associated with extraversion, as measured by the Short-form Revised Eysenck Personality Questionnaire.

Unraveling the Relation Between Personality and Well-Being in a Genetically Informative Design

In the current study, common and unique genetic and environmental influences on personality and a broad range of well-being measures were investigated. Data on the Big Five, life satisfaction, quality of life, self-rated health, loneliness, and depression from 14,253 twins and their siblings (age M: 31.82, SD: 14.41, range 16–97) from the Netherlands Twin Register were used in multivariate extended twin models. The best-fitting theoretical model indicated that genetic variance in personality and well-being traits can be decomposed into effects due to one general, common factor ( Mdn: 60%, range 15%–89%), due to personality-specific ( Mdn: 2%, range 0%–78%) and well-being-specific ( Mdn: 12%, range 4%–35%) factors, and trait-specific effects ( Mdn: 18%, range 0%–65%). Significant amounts of non-additive genetic influences on the traits’ (co)variances were found, while no evidence was found for quantitative or qualitative sex differences. Taken together, our study paints a fine-grained, complex picture of common and unique genetic and environmental effects on personality and well-being. Implications for the interpretation of shared variance, inflated phenotypic correlations between traits and future gene finding studies are discussed.

How similar are the conceptual and empirical structures of personality traits?

The congruity of the conceptual and empirical structures of personality traits was examined by comparing the structure of trait covariation ratings to the five‐factor structure of self‐reported traits. The covariation ratings were found to be highly reliable, and no evidence of systematic sex or age differences was found. Besides a rough similarity, there were replicable differences between the conceptual and empirical structures. Most importantly, Neuroticism and Extraversion had a weak negative correlation in self‐reports, but were judged to be almost bipolar opposites in covariation ratings; impulsiveness was judged to be a negative indicator of Conscientiousness in covariation ratings, but was equally strongly related to Neuroticism component in self‐ratings. These systematic differences demonstrate that the structure of self‐rated traits is not reducible to semantic similarities of traits descriptors. Copyright © 2006 John Wiley & Sons, Ltd.

Resilients, Overcontrollers, and Undercontrollers: The replicability of the three personality prototypes across informants

The study of patterns in personality structure reveals three replicable prototypes: Resilients, Overcontrollers, and Undercontrollers. The three prototypes were first identified in children using ratings based on the California Child Q‐set (see Block, 1971). Only recently, the three prototypes were replicated in self‐reports on questionnaires intended to assess the Big Five (see e.g. Asendorpf, Borkenau, Ostendorf, & van Aken, 2001). This paper addresses the question of whether the three prototypes are replicable across different data sources. Cluster structures in self‐, peer, and behaviour ratings, all based on the Big Five, were examined in a sample of 600 monozygotic and dizygotic twins ranging in age from 18 to 70 years. The three prototypes could be clearly identified in the self‐reports only, whereas in ratings by others only the Resilient prototype could be replicated. In both peer and behaviour ratings, the second and the third cluster reflected a Non‐desirable and an Average type. The analysis of cross‐data consistency revealed only moderate agreement in assignments of individual subjects to types. The findings suggest that personality types depend strongly on personality measures and informants. Copyright © 2003 John Wiley & Sons, Ltd.

Developmental trajectories to reduced activation of positive valence systems: A review of biological and environmental contributions

Reduced activation of positive valence systems (PVS), including blunted neural and physiological responses to pleasant stimuli and rewards, has been shown to prospectively predict the development of psychopathology. Yet, little is known about how reduced PVS activation emerges across development or what implications it has for prevention. We review genetic, temperament, parenting, and naturalistic and laboratory stress research on neural measures of PVS and outline developmentally-informed models of trajectories of PVS activation. PVS function is partly heritable and appears to reflect individual differences in early-emerging temperament traits. Although lab-induced stressors blunt PVS activation, effects of parenting and naturalistic stress on PVS are mixed and depend on the type of stressor, developmental timing, and interactions amongst risk factors. We propose that there may be multiple, dynamic developmental trajectories to reduced PVS activation in which combinations of genes, temperament, and exposure to severe, prolonged, or uncontrollable stress may exert direct and interactive effects on PVS function. Critically, these risk factors may alter PVS developmental trajectories and/or PVS sensitivity to proximal stressors. Distinct factors may converge such that PVS activation proceeds along a typical, accelerated, chronically low, or stress-reactive trajectory. Finally, we present directions for future research with translational implications.

Longitudinal associations between mothers' and fathers' anger/irritability expressiveness, harsh parenting, and adolescents' socioemotional functioning in nine countries

The present study examines parents' self-efficacy about anger regulation and irritability as predictors of harsh parenting and adolescent children's irritability (i.e., mediators), which in turn were examined as predictors of adolescents' externalizing and internalizing problems. Mothers, fathers, and adolescents (N = 1,298 families) from 12 cultural groups in 9 countries (China, Colombia, Italy, Jordan, Kenya, Philippines, Sweden, Thailand, and United States) were interviewed when children were about 13 years old and again 1 and 2 years later. Models were examined separately for mothers and fathers. Overall, cross-cultural similarities emerged in the associations of both mothers' and fathers' irritability, as well as of mothers' self-efficacy about anger regulation, with subsequent maternal harsh parenting and adolescent irritability, and in the associations of the latter variables with adolescents' internalizing and externalizing problems. The findings suggest that processes linking mothers' and fathers' emotion socialization and emotionality in diverse cultures to adolescent problem behaviors are somewhat similar. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Dispositional negativity, cognition, and anxiety disorders: An integrative translational neuroscience framework

When extreme, anxiety can become debilitating. Anxiety disorders, which often first emerge early in development, are common and challenging to treat, yet the underlying mechanisms have only recently begun to come into focus. Here, we review new insights into the nature and biological bases of dispositional negativity, a fundamental dimension of childhood temperament and adult personality and a prominent risk factor for the development of pediatric and adult anxiety disorders. Converging lines of epidemiological, neurobiological, and mechanistic evidence suggest that dispositional negativity increases the likelihood of psychopathology via specific neurocognitive mechanisms, including attentional biases to threat and deficits in executive control. Collectively, these observations provide an integrative translational framework for understanding the development and maintenance of anxiety disorders in adults and youth and set the stage for developing improved intervention strategies.

Genetic and Environmental Pathways Underlying Personality Traits and Perceived Stress: Concurrent and Longitudinal Twin Studies

The present study examined the genetic and environmental etiology underlying the Big Five personality traits and perceived stress, concurrently and longitudinally. In study 1, we used the twin sample from the National Longitudinal Study of Adolescent to Adult Health (Add Health IV) data. The results indicated that about 70% of the association between the Big Five personality traits and perceived stress was due to genetic influences. In study 2, we used the twin sample from the Midlife in the United States Survey (MIDUS I and II) to examine the genetic and environmental influences underlying the longitudinal relations between the Big Five personality traits and perceived stress. The results suggested that continuity in perceived stress was primarily accounted for by genetic influences, and changes in perceived stress were mainly due to nonshared environmental influences. The continuity in the association between the five personality traits and perceived stress was largely accounted for by genetic factors, and nonshared environmental factors made greater contributions to changes in the association between personality traits and perceived stress. Among the Big Five personality traits, the genetic components in conscientiousness and neuroticism made substantial contributions to the genetic link between personality traits and perceived stress across both studies.

Origins of adulthood personality: The role of adverse childhood experiences

We test whether adverse childhood experiences - exposure to parental maltreatment and its indirect effect on health - are associated with age 30 personality traits. We use rich longitudinal data from a large, representative cohort of young US Americans and exploit differences across siblings to control for the confounding influences of shared environmental and genetic factors. We find that maltreatment experiences are significantly and robustly associated with neuroticism, conscientiousness, and openness to experience, but not with agreeableness and extraversion. High levels of neuroticism are linked to sexual abuse and neglect; low levels of conscientiousness and openness to experience are linked to parental neglect. The associations are partially explained by the indirect effects of maltreatment on adolescence physical and mental health. Maltreatment experiences, in combination with their health effects, explain a substantial fraction of the relationship between adulthood conscientiousness and earnings or human capital. Our findings provide a possible explanation for why personality traits are important predictors of adulthood labor market outcomes.

Causal Unity of Broader Traits is an Illusion

Mõttus alerts us to the widespread predictive heterogeneity of different indicators of the same trait. This heterogeneity violates the assumption that traits have causal unity in their developmental antecedents and effects on outcomes. I would go a step further: broader traits are useful units for description and prediction but not for explaining personality development and personality effects. In most cases, the measured trait indicators are closer to relevant causal mechanisms, and within a network perspective on personality, broader traits as entities with causal potential can be dismissed completely. Copyright © 2016 European Association of Personality Psychology

Psychology as the Science of Self-Reports and Finger Movements: Whatever Happened to Actual Behavior?

Psychology calls itself the science of behavior, and the American Psychological Association's current "Decade of Behavior" was intended to increase awareness and appreciation of this aspect of the science. Yet some psychological subdisciplines have never directly studied behavior, and studies on behavior are dwindling rapidly in other subdisciplines. We discuss the eclipse of behavior in personality and social psychology, in which direct observation of behavior has been increasingly supplanted by introspective self-reports, hypothetical scenarios, and questionnaire ratings. We advocate a renewed commitment to including direct observation of behavior whenever possible and in at least a healthy minority of research projects.

The Little Six Personality Dimensions From Early Childhood to Early Adulthood: Mean-Level Age and Gender Differences in Parents' Reports

The present research pursues three major goals. First, we develop scales to measure the Little Six youth personality dimensions: Extraversion, Agreeableness, Conscientiousness, Neuroticism, Openness to Experience, and Activity. Second, we examine mean-level age and gender differences in the Little Six from early childhood into early adulthood. Third, we examine the development of more specific nuance traits. We analyze parent reports, made using the common-language California Child Q-Set (CCQ), for a cross-sectional sample of 16,000 target children ranging from 3 to 20 years old. We construct CCQ-Little Six scales that reliably measure each Little Six dimension. Using these scales, we find (a) curvilinear, U-shaped age trends for Agreeableness, Conscientiousness, and Openness, with declines followed by subsequent inclines; (b) monotonic, negative age trends for Extraversion and Activity; (c) higher levels of Conscientiousness and Agreeableness among girls than boys, as well as higher levels of Activity among boys than girls; and (d) gender-specific age trends for Neuroticism, with girls scoring higher than boys by mid-adolescence. Finally, we find that several nuance traits show distinctive developmental trends that differ from their superordinate Little Six dimension. These results highlight childhood and adolescence as key periods of personality development.

Psychometric Comparison of Self- and Informant-Reports of Personality

Self-reports are the most relied on assessment method in psychology. In the area of personality, informant-reports are a reasonable alternative assessment strategy. However, agreement between self- and informant-reports of personality is only moderately good. A portion of the observed discrepancies between self- and informant-reports of personality may come from differences in psychometric measurement across raters. That is, it is unknown whether the constructs assessed via self- and informant-reports are psychometrically identical. We examined four key personality scales--Well-Being, Social Closeness, Stress Reaction, and Harm Avoidance--in male and female dyads who provided self- and informant-reports for their partner. Similarities in self- and informant-reports of personality were evaluated by testing measurement invariance. Overall, models supported configural, metric, and scalar invariance for each of the four personality dimensions. These results suggest that the same psychometric constructs are assessed via self- and informant-reports of these personality dimensions. Informant-reports can be used in studies to avoid biases from relying solely on self-reports.

Structure of observed temperament in middle childhood

Although much is known about the structure of adult temperament and personality, significantly less is known about the structure of child temperament. We examined the structure of child temperament in 205 seven-year-olds using observational measures. Exploratory factor analysis identified factors representing positive emotionality/sociability, disinhibition/anger, fear/behavioral inhibition, and sadness. The predictive validity of these dimensions was evaluated by examining their associations with children's internalizing and externalizing symptoms: positive emotionality/sociability showed positive associations with ADHD symptoms, disinhibition/anger showed positive associations with externalizing symptoms, fear/behavioral inhibition showed negative associations with ADHD and CD symptoms, and sadness showed positive associations with both internalizing and externalizing problems. These associations were consistent with extant literature on temperament and psychopathology, supporting the validity of the structure obtained.

Do Men Vary More than Women in Personality? A Study in 51 Cultures

Do men vary more than women in personality? Evolutionary, genetic, and cultural arguments suggest that hypothesis. In this study we tested it using 12,156 college student raters from 51 cultures who described a person they knew well on the 3rd-person version of the Revised NEO Personality Inventory. In most cultures, male targets varied more than female targets, and ratings by female informants varied more than ratings by male informants, which may explain why higher variances for men are not found in self-reports. Variances were higher in more developed, and effects of target sex were stronger in more individualistic societies. It seems that individualistic cultures enable a less restricted expression of personality, resulting in larger variances and particularly so among men.

Heritability and fitness correlates of personality in the Ache, a natural-fertility population in Paraguay

The current study assessed the heritability of personality in a traditional natural-fertility population, the Ache of eastern Paraguay. Self-reports (n = 110) and other-reports (n = 66) on the commonly used Big Five Personality Inventory (i.e., extraversion, agreeableness, conscientiousness, neuroticism, openness) were collected. Self-reports did not support the Five Factor Model developed with Western samples, and did not correlate with other-reports for three of the five measured personality factors. Heritability was assessed using factors that were consistent across self- and other-reports and factors assessed using other-reports that showed reliabilities similar to those found in Western samples. Analyses of these items in combination with a multi-generation pedigree (n = 2,132) revealed heritability estimates similar to those found in most Western samples, although we were not able to separately estimate the influence of the common environment on these traits. We also assessed relations between personality and reproductive success (RS), allowing for a test of several mechanisms that might be maintaining heritable variation in personality. Phenotypic analyses, based largely on other-reports, revealed that extraverted men had higher RS than other men, but no other dimensions of personality predicted RS in either sex. Mothers with more agreeable children had more children, and parents mated assortatively on personality. Of the evolutionary processes proposed to maintain variation in personality, assortative mating, selective neutrality, and temporal variation in selection pressures received the most support. However, the current study does not rule out other processes affecting the evolution and maintenance of individual differences in human personality.

Observed Personality in Childhood: Psychometric and Behavioral Genetic Evidence of Two Broad Personality Factors

We examined broad dimensions of children's personalities (total n = 1056; age = 3.5 to 12 years) based on observers' perceptions following a few hours of structured interaction. Siblings' behaviors during a two-hour cognitive assessment in the home were rated separately by two different observers. Exploratory and confirmatory factor analyses clearly revealed a two-factor solution in three different samples. There was correspondence between parent-rated temperament and the observer-rated factors. Cross-sectional analyses indicated lower Plasticity among older children and higher Stability among older children. Sex differences were negligible. Plasticity and Stability were correlated in the .2 to .3 range. Most of the sibling similarity in the Plasticity was due to additive genetic influences, whereas most sibling similarity in Stability was attributable to shared environmental influences. The findings implicate a biometric factor structure to childhood personality that fits well with emerging bio-social theories of personality development.

The role of the catechol-O-methyltransferase (COMT) gene in personality and related psychopathological disorders

This review provides a short overview of the most significant biologically oriented theories of human personality. Personality concepts of Eysenck, Gray and McNaughton, Cloninger and Panksepp will be introduced and the focal evidence for the heritability of personality will be summarized. In this context, a synopsis of a large number of COMT genetic association studies (with a focus on the COMT Val158Met polymorphism) in the framework of the introduced biologically oriented personality theories will be given. In line with the theory of a continuum model between healthy anxious behavior and related psychopathological behavior, the role of the COMT gene in anxiety disorders will be discussed. A final outlook considers new research strategies such as genetic imaging and epigenetics for a better understanding of human personality.

CoSMoS and TwinPaW: Initial Report on Two New German Twin Studies

After briefly recapitulating two earlier German twin studies (BiLSAT and GOSAT), we present two new German twin studies with a longitudinal perspective: CoSMoS and TwinPaW. The twin study on Cognitive ability, Self-reported Motivation and School performance (CoSMoS) aims to investigate predictors and influences of school performance in a genetically sensitive design, beginning with children in late elementary school. The Twin study on Personality And Wellbeing (TwinPaW) focuses on adult personality and its relation to physical health as well as health-related behavior in an adult sample of twins. Both studies are characterized by an effort to recruit new large twin samples through a novel recruitment procedure aimed at reducing self-selective sampling. In two German federal states, contact information on persons born on the same day and with the same name was retrieved from record sections. From the resulting pool of more than 36,000 addresses we contacted approximately 2000 parents of twins aged 9 and 10 for CoSMoS, as well as 2000 adult twin pairs for TwinPaW by telephone and mail. Personal contact by telephone proved to be more efficient with agreement rates of 63% in the children sample and 65% in the adult sample. In this article we briefly describe the rationale and the study aims of CoSMoS and TwinPaW as well as the characteristics of the sample we have recruited so far.

The Jena Twin Registry and the Jena Twin Study of Social Attitudes (JeTSSA)

The Jena Twin Registry focuses on identifying twins in eastern Germany. It is based in part on registers of multiple births and data from registration offices, and in part on a volunteer sample approached by media calls and twin clubs. The Jena Twin Study of Social Attitudes (JeTSSA) is the first study based on the Jena Twin Registry. In a sample of 226 monozygotic and 168 dizygotic adult twin pairs, self- and independent reports of significant others (peers, spouses, parents) are collected to estimate genetic and environmental effects on social attitudes and the covariation of genetic influences on personality traits and social attitudes. In addition, the effects of measured environmental variables on attitude formation are examined.

Genetic and environmental influences on impulsivity: a meta-analysis of twin, family and adoption studies

A meta-analysis of twin, family and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on impulsivity. The best fitting model for 41 key studies (58 independent samples from 14 month old infants to adults; N=27,147) included equal proportions of variance due to genetic (0.50) and non-shared environmental (0.50) influences, with genetic effects being both additive (0.38) and non-additive (0.12). Shared environmental effects were unimportant in explaining individual differences in impulsivity. Age, sex, and study design (twin vs. adoption) were all significant moderators of the magnitude of genetic and environmental influences on impulsivity. The relative contribution of genetic effects (broad sense heritability) and unique environmental effects were also found to be important throughout development from childhood to adulthood. Total genetic effects were found to be important for all ages, but appeared to be strongest in children. Analyses also demonstrated that genetic effects appeared to be stronger in males than in females. Method of assessment (laboratory tasks vs. questionnaires), however, was not a significant moderator of the genetic and environmental influences on impulsivity. These results provide a structured synthesis of existing behavior genetic studies on impulsivity by providing a clearer understanding of the relative genetic and environmental contributions in impulsive traits through various stages of development.

Genetic influences on alexithymia and their relationship with depressive symptoms

OBJECTIVE

The factors involved in the etiology of alexithymia are still unclear. While a few studies suggested substantial genetic influences on alexithymia, it remains to be determined if these influences are independent of genetic influences on other mental health variables correlated with alexithymia, such as depression. This study is aimed at confirming previous findings of a genetic contribution to alexithymia, examining whether there are genetic or environmental influences common to alexithymia facets, and investigating whether genetic influences on alexithymia are independent of genetic influences on depression.

METHODS

The 20-item Toronto Alexithymia Scale and a validated measure of depression were administered to a sample of 729 twins (45% males) aged 23-24 years drawn from the population-based Italian Twin Register. Genetic structural equation modeling was performed with the Mx program.

RESULTS

Genetic factors accounted for 42% of individual differences in alexithymia. Unshared environmental factors explained the remaining proportion of variance. There was a substantial (0.65) genetic correlation between alexithymia and depression. The inclusion of depression as a covariate in the genetic models reduced the heritability estimate for alexithymia to 33%.

CONCLUSIONS

Despite some limitations, this study corroborates the notion that genetic factors contribute substantially to individual differences in alexithymia, with unshared environmental factors also playing an important role. Also, it suggests a genetic link between alexithymia and depression.

The complexity of personality: advantages of a genetically sensitive multi-group design

Findings from many behavioral genetic studies utilizing the classical twin design suggest that genetic and non-shared environmental effects play a significant role in human personality traits. This study focuses on the methodological advantages of extending the sampling frame to include multiple dyads of relatives. We investigated the sensitivity of heritability estimates to the inclusion of sibling pairs, mother-child pairs and grandparent-grandchild pairs from the German Socio-Economic Panel Study in addition to a classical German twin sample consisting of monozygotic- and dizygotic twins. The resulting dataset contained 1.308 pairs, including 202 monozygotic and 147 dizygotic twin pairs, along with 419 sibling pairs, 438 mother-child dyads, and 102 grandparent-child dyads. This genetically sensitive multi-group design allowed the simultaneous testing of additive and non-additive genetic, common and specific environmental effects, including cultural transmission and twin-specific environmental influences. Using manifest and latent modeling of phenotypes (i.e., controlling for measurement error), we compare results from the extended sample with those from the twin sample alone and discuss implications for future research.

Environment, genes, and experience: lessons from behavior genetics

The article reviews the theoretical analysis of the problems inherent in studying the environment within behavior genetics across several periods in the development of environmental studies in behavior genetics and proposes some possible alternatives to traditional approaches to studying the environment in behavior genetics. The first period (from the end of the 1920s to the end of the 1970s), when the environment was not actually studied, is called pre-environmental; during this time, the basic principles and theoretical models of understanding environmental effects in behavior genetics were developed. The second period is characterized by the development of studies on environmental influences within the traditional behavior genetics paradigm; several approaches to studying the environment emerged in behavior genetics during this period, from the beginning of the 1980s until today. At the present time, the field is undergoing paradigmatic changes, concerned with methodology, theory, and mathematical models of genotype-environment interplay; this might be the beginning of a third period of development of environmental studies in behavior genetics. In another part, the methodological problems related to environmental studies in behavior genetics are discussed. Although the methodology used in differential psychology is applicable for assessment of differences between individuals, it is insufficient to explain the sources of these differences. In addition, we stress that psychoanalytic studies of twins and their experiences, initiated in the 1930s and continued episodically until the 1980s, could bring an interesting methodology and contribute to the explanation of puzzling findings from environmental studies of behavior genetics. Finally, we will conclude with implications from the results of environmental studies in behavior genetics, including methodological issues.

Personality development: continuity and change over the life course

The development of personality across the human life course may be observed from three different standpoints: the person as actor (behaving), agent (striving), and author (narrating). Evident even in infancy, broad differences in social action patterns foreshadow the long-term developmental elaboration of early temperament into adult dispositional traits. Research on personal strivings and other motivational constructs provides a second perspective on personality, one that becomes psychologically salient in childhood with the consolidation of an agentic self and the articulation of more-or-less stable goals. Layered over traits and goals, internalized life stories begin to emerge in adolescence and young adulthood, as the person authors a narrative identity to make meaning out of life. The review traces the development of traits, goals, and life stories from infancy through late adulthood and ends by considering their interplay at five developmental milestones: age 2, the transition to adolescence, emerging adulthood, midlife, and old age.

Variation in DRD2 dopamine gene predicts Extraverted personality

Quantitative geneticists estimate the heritability of Extraverted personality to be around 40-60%. Theory and research which links Extraversion with variation in dopaminergic function suggests that dopaminergic genes should be a start-point for molecular genetic investigations of this trait. Recent endeavours in this area have met with some encouragement but also setbacks. In this study, we investigate the relationship between Extraversion and the DRD2 TaqIA/ANKK1 polymorphism in 224 university students. Presence of at least one copy of the A1 allele was associated with significantly higher Extraversion. The robustness of this finding was confirmed through bootstrap analysis. Findings are discussed in relation to the broader literature, in particular, methodological issues which may have obscured this finding in previous research.

Applications of generalizability theory to clinical child and adolescent psychology research

Using generalizability theory to evaluate the reliability of child and adolescent measures enables researchers to enhance precision of measurement and consequently increase confidence in research findings. With an observer-rated measure of child self-regulation, we illustrate how multiple sources of error variance (e.g., raters, items) affect the dependability (replicability) of scores and demonstrate methods for enhancing dependability of observer ratings. Using ratings of 181 children, we illustrate the use of two-facet (i.e., raters and items as sources of error) and three-facet (i.e., raters, items and occasions) analyses to optimize design features of future studies using this measure. In addition, we show how generalizability theory provides a useful conceptual framework for thinking about determinants of scores on acquaintance (e.g., teacher or parent) ratings, as well as observer ratings, and sheds light on the strengths and limitations of both types of data for child and adolescent clinical research.

Genetic covariation among facets of openness to experience and general cognitive ability

Genetic and environmental sources of covariation among cognitive measures of verbal IQ, performance IQ (PIQ), academic achievement, 2-choice reaction time (CRT), inspection time (IT) and the 6 Openness facets of the NEO Personality Inventory-Revised (NEO PI-R) were examined. The number of twin and twin-sibling pairs ranged from 432 (182 MZ, 350 DZ/sibling) to 1023 (273 MZ, 750 DZ/sibling) for cognitive measures, and between 432 (90 MZ, 342 DZ/sibling) - 437 (91 MZ, 346 DZ/sibling) for Openness facets. Structural equation modeling best supported a model with a 3-factor additive genetic structure. A genetic general factor subsumed the 5 cognitive measures and 5 of the 6 Openness facets (Actions did not load significantly). A second additive genetic factor incorporated the 6 Openness facets, and a third additive genetic factor incorporated the 5 cognitive measures. Specific additive and dominance genetic effects were also evident, as were shared common and shared unique environmental influences, and specific unique environmental effects. The Openness facets of Ideas and Values evidenced the strongest phenotypic correlations with cognitive indices, particularly verbal measures. The genetic correlations among Openness facets and cognitive measures ranged from -.06 to .79. Results were interpreted as suggesting that Openness is related to general cognitive ability (g) through a genetic mechanism and that gengenders a minor but discernable disposition towards Openness for the majority of facets.

Genes, personality, and attachment in adults: a multivariate behavioral genetic analysis

Behavioral genetic methods were used to estimate genetic and environmental contributions to (a) attachment-related anxiety and avoidance and (b) the overlap between these attachment dimensions and the Big Five personality traits. Two major findings emerged from these analyses. First, individual differences in attachment-related anxiety and avoidance were heritable, and second, much of the overlap between adult attachment and the Big Five traits was due to shared genetic influences. Discussion focuses on the implications of these results for attachment theory and research and provides a speculative account of the interplay between temperamental dimensions and internal working models of relationships across the life span.

Ich mag dich und du mich (nicht)?

Zusammenfassung. Mit Zwillingen lassen sich nicht nur Fragestellungen zum Thema Erbe-Umwelt untersuchen. Sie sind auch ein aufschlussreicher Fall für die Identitätsentwicklung, wenn sie im Vergleich zu Nicht-Zwillingen über ihre Geschwisterbeziehung befragt werden. In der vorliegenden Studie geben 65 Zwillingspaare (24 Monozygote, 21 gleich- und 20 gegengeschlechtlich Dizygote) anhand des Braunschweiger Paaridentitätsfragebogens für Geschwister (BPIG) Auskunft über ihre Beziehung. Ihre Aussagen, die zu drei Messzeitpunkten erhoben wurden, werden mit denen von 22 gleich- und 20 gegengeschlechtlichen Geschwisterpaaren (Altersabstand max. 2 Jahre) verglichen. Zum ersten Messzeitpunkt sind die Kinder zwischen 9 und 13 Jahren alt (Durchschnittsalter 11.2, SD = 1.4), Folgeinterviews wurden ein bzw. zwei Jahre nach der ersten Erhebung durchgeführt. Im Zentrum der Auswertung der dyadischen und damit korrelierten Daten, die anhand von Übereinstimmungsmaßen und durch Mehrebenenanalysen für jeden Messzeitpunkt erfolgt, steht die (nicht) übereinstimmende Wahrnehmung der Beziehung beider Kinder (dyadische Ebene) sowie die individuelle Beurteilung verschiedener Beziehungsaspekte (individuelle Ebene). Überprüft wird, ob die Zugehörigkeit zu einer bestimmten Geschwisterkonstellation eine Vorhersage der Werte erlaubt und ob für die Gruppen unterschiedliche Entwicklungsverläufe während der Pubertät zu verzeichnen sind. Die Ergebnisse zeigen, dass vor allem monozygote Zwillinge signifikant höhere Übereinstimmungswerte erreichen, was allerdings nicht auf eine höhere emotionale Nähe zurückzuführen ist. Auswirkungen auf die Identitätsentwicklung und die Auswertungsverfahren werden diskutiert.

Assessing the Big Five

Abstract. A new measure of the Big Five personality constructs, the Openness Conscientiousness Extraversion Agreeableness Neuroticism Index Condensed (OCEANIC), was developed and validated. In Study 1 (N = 166), the convergent validity with the Big Five as assessed by the NEO-FFI was established. Study 2 (N = 3 808) served to investigate the structure of the instrument with stepwise exploratory factor analysis and confirmatory factor analysis. The incremental predictive validity with respect to objective university grades was examined in Study 3 (N = 145). The results show that a) the scales of the initial item pool converge with those of an established measure of the Big Five, b) the Big Five factor model fits the data both at the item and facet level and both for subsamples of students and workers, and c) consistent with previous research, the Conscientiousness factor of the OCEANIC predicts university grades beyond intelligence measures.

Deviant Peer Affiliation and Problem Behavior: A Test of Genetic and Environmental Influences

This study uses a multitrait, multimethod (MTMM) approach to investigate the genetic and environmental etiologies of childhood deviant peer affiliation (DPA) and problem behavior (PROB). The variability of genetic and environmental estimates by agent and method is also examined. A total of 77 monozygotic and 72 dizygotic twin pairs and each twin's close friend were assessed. The informants included parents, teachers, and twins, and the methods involved questionnaire reports and coder ratings of videotaped dyadic interactions between each twin and their close friend. Twin intraclass correlations and univariate models attributed DPA and PROB to genetic, and shared and nonshared environmental effects. Parameter estimates differed by rater and method, however. Results accentuate the imperative to attend to method effects inherent in MTMM behavioral geneticresearch.

5-HT 1A polymorphism and self-transcendence in mood disorders

Recently, an association between serotonin 1A receptor binding potential and self-transcendence scores at the temperament and character inventory (TCI) has been reported. We tested involvement of 5-HT(1A) gene in this trait, in a sample of 40 remitted mood disorder patients. Subjects with the 5-HT(1A)*C/C genotype showed significantly lower scores at the total self-transcendence and at the sub-scales of transpersonal identification and spiritual acceptance. Our preliminary results further support the involvement of the serotoninergic pattern in the self-transcendence character trait.