Verhaltensgenetik

Behavioural genetics has provided ample evidence for the influence of genes on personality traits and psychological disorders. In this review, the methodological strategies of behavioural genetics are described and study results with special relevance for psychotherapists are highlighted.Moreover, some traditional myths and misunderstandings are discussed. In particular, two findings are underscored: While genetic factors substantially contribute to the development of personality traits, environmental influences shared by the members of a family appear to be virtually absent. In contrast, environmental factor specific to an individual seem to play an important role.Second, genes do not only have a direct impact on the development of psychological disorders, but also act in an indirect way by increasing the probability of exposure to stressful life events which in turn function as risk factors for psychological disorders. It is concluded that research should incorporate both genetic and environmental factors to be able to evaluate their relative impact and elucidate the interaction of nature and nurture.     

Beyond the heritability of life satisfaction – The roles of personality and twin-specific influences

In a behavior genetic design, we investigated individual differences in life satisfaction and its relation to personality with respect to both internal and external influences. We questioned the absence of shared environment and examined the specific contribution of additive and non-additive genetic influences. We also tested for twin-specific environmental influences in a total sample of 1308 dyads including identical and fraternal twins, siblings, mother–child and grandparent–child pairs. The results showed substantial shared environmental influences on life satisfaction that varied between twins and non-twins, supporting twin-specific environmental influences. Additive and non-additive genetic influences on life satisfaction were completely shared with personality. The remaining variance could be explained by unique non-shared environmental influences for life satisfaction independent of personality.     

Analysis of genetic influences on the consistency and variability of the Big Five across different stressful situations

Several studies have demonstrated that individual differences in personality traits, known as the Big Five, have a genetic component. These personality traits are considered important predictors of everyday behaviour. In addition to personality traits there are also factors in the environment that govern behaviour. This dual influence on behaviour is statistically reflected in a P × S interaction. This study examines the genetic and environmental influences on the interactions between a person and his daily life environment for the Big Five. Fifty‐seven identical twin pairs and 43 fraternal twin pairs participated in this study. Trait related behaviour was measured in 30 different situations with the aid of an SR inventory. The heritability coefficients for the main effect of P were in the normal range, varying between 0.35 for Agreeableness and 0.53 for Conscientiousness. The heritability coefficients for the P × S interactions were moderately high, explaining between 26% and 69% of the total P × S variance. The consequences of these results for general and behavioural genetic research on the Big Five will be discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

多巴胺相关基因甲基化、家庭环境与创造力的关系

“遗传与环境”的争论一直是创造力研究的核心问题, 但目前对于环境以及遗传与环境交互作用对创造力影响的分子生物机制还未有研究涉及。近年来, 随着表观遗传学的兴起, 揭示影响心理行为的表观遗传机制现已成为心理学研究的热点。作为环境与基因组之间的纽带, 表观遗传学研究为揭示环境以及遗传与环境交互作用对创造力影响的分子生物机制提供了机遇。本研究以多巴胺相关基因、家庭环境以及两者对于创造力的交互作用为切入点, 对影响创造力的表观遗传机制进行考察, 并在此基础之上, 对环境以及遗传与环境交互作用对创造力影响的分子生物机制进行探索。具体研究内容包括：(1)通过对多巴胺相关基因甲基化模式与创造力关系的系统考察, 筛选出甲基化模式与创造力有关的基因; (2)对筛选出的基因, 进一步考察其甲基化模式在家庭环境及其遗传多态性与家庭环境交互作用对创造力影响中的中介作用。本研究有助于揭示创造力的表观遗传机制, 深化关于遗传与环境对创造力影响的作用机制的理解。     

Personality Trait Change in Adulthood

ABSTRACT— Recent longitudinal and cross-sectional aging research has shown that personality traits continue to change in adulthood. In this article, we review the evidence for mean-level change in personality traits, as well as for individual differences in change across the life span. In terms of mean-level change, people show increased self-confidence, warmth, self-control, and emotional stability with age. These changes predominate in young adulthood (age 20–40). Moreover, mean-level change in personality traits occurs in middle and old age, showing that personality traits can change at any age. In terms of individual differences in personality change, people demonstrate unique patterns of development at all stages of the life course, and these patterns appear to be the result of specific life experiences that pertain to a person's stage of life.     

Genetic and environmental influences on person-situation interactions

Genetic and environmental influences on person-situation and person-mode of response interactions for anxiety and for dominance were investigated in an adult twin sample. For anxiety, evidence of significant genetic variance was found for the person-situation interaction and the person-mode of response interaction. For dominance, evidence of shared sibling-environmental influences was found for the person-situation interaction. Sex differences in the patterns of findings were also examined. The data indicate that the factors influencing personsituation interactions vary depending on the specific trait studied, and the results provide empirical support for the “interactionist” hypothesis that an individual's behavior can be characterized by meaningful patterns of behavior across situations. In addition, the study illustrates that behavior-genetic research can be designed to address important theoretical questions about the nature of personality.     

多巴胺、5-羟色胺通路相关基因及家庭环境对创造力的影响及其作用机制

创造力的遗传基础是近年来创造力研究领域的前沿和热点问题, 但仍尚处于起步阶段, 也未有研究系统探讨遗传与环境因素的交互作用对创造力的影响及其作用机制。本课题拟在中国汉族人群中考察多巴胺(DA)、5-羟色胺(5-HT)神经递质通路上的32个基因约700个多态性位点与创造力的关系, 并首次探讨家庭环境在遗传多态性与创造力关系中的调节作用。研究内容包括：(1)通过单基因、基于通路以及基因—基因交互作用的关联分析, 考察遗传多态性对创造力的影响, 揭示创造力的遗传基础; (2)通过基因—环境交互作用的关联分析, 考察家庭环境在遗传与创造力关系中的调节作用; (3)通过结构方程模型的比较分析, 揭示遗传与家庭环境在创造力两个方面(创造思维与创造人格)共享的与特异的作用机制。该项目成果能够从遗传与环境交互作用的角度阐明创造力个体差异的原因, 有助于构建基于创造力个体差异分析的理论模型, 对创造人才的鉴别和培养具有重要现实意义。     

Caught on camera: Cross-race interactions captured in daily life

The present study examined the prevalence of cross-race interactions occurring in daily life using wearable camera technology that captures photographs of a participants’ immediate environment and social interactions. Coders used appearance-based cues to identify the number of interaction partners captured in the photos who appeared to be White or a racial minority. We found that 29.6% of Whites’ social interactions were with racial minorities and 23.9% of racial minorities’ social interactions were with Whites. Furthermore, we examined whether personality and other individual differences correlated with being captured in more cross-race interactions. We found that Whites who used more emotion-focused coping and less emotional suppression were more likely to be captured engaging in cross-race interactions.     

Wendy Johnson: Award for Distinguished Scientific Early Career Contributions to Psychology

Presents Wendy Johnson, the 2011 winner of the American Psychological Association Award for Distinguished Scientific Early Career Contributions to Psychology. "For innovative research explicating the nature, origin, and consequences of individual differences in intelligence and personality. With methodological rigor and theoretical incisiveness, Wendy Johnson has addressed some of the most vexing questions in the psychology of individual differences. She has shown how genetic and environmental factors jointly influence many important life outcomes, explicated the structure of cognitive abilities, and demonstrated how cognitive ability and personality contribute to gender differences in academic achievement. Her consummate mastery of research methodology, genetics, personality theory, and human abilities has enabled her to advance an integrative program of research that is having a fundamental impact on the field." (PsycINFO Database Record (c) 2011 APA, all rights reserved).     

Personal vulnerability, life events, and depressive symptoms: a test of a specific interactional model

We tested Beck's (1983) hypothesis that depressive symptoms occur when an individual experiences a negative life event that specifically matches the individual's personal motivational vulnerability. Ninety-eight undergraduates completed measures of depression level, recent life events, and sociotropic and autonomous achievement motivations. Consistent with the theory, sociotropy was associated with depression level and also served as a moderator of the relations between depression and frequency of recent negative social events. However, sociotropy also demonstrated nonpredicted interactive effects with negative events categorized a priori as autonomy related. Autonomy was unrelated to depression and showed no evidence of being a vulnerability to any type of life event. The findings generally support the value of examining the role in depression of interactions between personality characteristics and life events, although they do not support the specific matching predictions.     

Personality Change in Middle Adulthood: With Focus on Differential Susceptibility

Abstract

Little attention has been paid to middle adulthood in research on personality stability and change. In addition, previous research on individual differences in personality change has not fully explained its variability. This study focused on the differential susceptibility model, which suggests that individual susceptibility interacts with environmental factors and produces variability in outcomes, and investigated individual differences in personality change with a middle adult sample. A total of 1051 Japanese middle adults (M?=?41.61?years; SD = 5.31; range 30–50?years; 534 females) participated in this two-wave short-term longitudinal study. Latent change score model analyses revealed substantial mean-level declines in Agreeableness and Honesty–Humility. Moreover, the results showed that the influences of some life events on personality change are moderated for better and for worse by individual susceptibility to one’s environment. These findings suggest that the trends of personality development may differ between Western and non-Western countries and that differential susceptibility model may play an important role in deriving individual differences in personality stability and change.     

The juvenile transition: A developmental switch point in human life history

This paper presents a new perspective on the transition from early to middle childhood (i.e., human juvenility), investigated in an integrative evolutionary framework. Juvenility is a crucial life history stage, when social learning and interaction with peers become central developmental functions; here it is argued that the “juvenile transition” is a developmental switch point in the human life history, when both sex-related and individual differences in reproductive strategies are expressed after the assessment period provided by early childhood. Adrenarche, the secretion of adrenal androgens starting at the beginning of middle childhood, is proposed as the endocrine mechanism mediating the juvenile transition. It is argued that, in connection with the stress system, adrenal androgens enable adaptive plasticity in the development of reproductive strategies through integration of environmental and genetic factors. Finally, evidence is reviewed of both sex-related and individual differences arising during the juvenile transition, in the domains of attachment and aggression. Juvenility plays a central role in the ontogeny of behavior and personality; this paper contributes to defining its place within an integrated model of human development.     

Unravelling the Interplay Between Genetic and Environmental Contributions in the Unfolding of Personality Differences from Early Adolescence to Young Adulthood

In two studies, we examined the genetic and environmental sources of the unfolding of personality trait differences from childhood to emerging adulthood. Using self‐reports from over 3000 representative German twin pairs of three birth cohorts, we could replicate previous findings on the primary role of genetic sources accounting for the unfolding of inter‐individual differences in personality traits and stabilizing trait differences during adolescence. More specifically, the genetic variance increased between early (ages 10–12 years) and late (ages 16–18 years) adolescence and stabilized between late adolescence and young adulthood (ages 21–25 years). This trend could be confirmed in a second three‐wave longitudinal study of adolescents' personality self‐reports and parent ratings from about 1400 Norwegian twin families (average ages between 15 and 20 years). Moreover, the longitudinal study provided evidence for increasing genetic differences being primarily due to accumulation of novel genetic influences instead of an amplification of initial genetic variation. This is in line with cumulative interaction effects between twins' correlated genetic makeups and environmental circumstances shared by adolescent twins reared together. In other words, nature × nurture interactions rather than transactions can account for increases in genetic variance and thus personality variance during adolescence. © 2019 European Association of Personality Psychology     

An Interactionist Perspective on Genetic and Environmental Contributions to Personality

It is now well established that nature and nurture are both important contributors to variation in human personality. As a result, the field of personality behavior genetics is moving beyond simply estimating the magnitude of genetic and environmental influences on various personality constructs. Recent methodological advances provide for the study of how these different sources of influence interact in the development of personality. Specifically, newer biometrical moderation models allow for group‐specific estimates of heritability and environmental influences on personality (a form of gene–environment interaction). In the current paper, we review selected recent research using these models. Furthermore, we explore how moderation might also be important in understanding links between specific genes and personality. Accounting for the contingencies between genes and environment will be an important catalyst for the molecular genetic study of personality, as unmoderated ‘main effect’ types of gene → personality associations have been elusive.     

Genetic and Environmental Contributions to Individual Differences: The Three Major Dimensions of Personality

ABSTRACT This article deals with the contribution of genetic and environmental factors to individual differences in the three major dimensions of personality (Psychoticism, Extraversion, and Neuroticism) Twin studies indicate, and family studies confirm within limits, the strong genetic determination of these and many other personality factors, additive genetic variance accounting for roughly half the total phenotypic variance On the environmental side, shared family environment plays little or no part, all environmental effects being within-family Assortative mating, important in the formation of social attitudes, has little impact on personality Dominance may be important for Extraversion Epistasis (emergenesis) may account for the comparative low values of dizygotic (DZ) twins' correlations Evidence for differential heritability of traits is present, but not very strong It is concluded that behavioral genetics forms a vital part of the psychological understanding of the causes of individual differences in personality     

The nature (and nurture) of personality disorders

Personality disorders have a long history in the literature but a short scientific history. The point prevalence of personality disorders is 10%, but the lifetime prevalence is probably 30–40%. Genetic factors contribute to around 40–50% of the variation in the development of personality disorders. The effect of shared environment is very small or non‐existent. Some researchers have tried to promote gene‐environment interaction. However, in reality, the studies investigated gene‐situation interaction, as the “environment” may in reality be partly of a genetic nature. Thus, we are dealing with an unknown part of gene‐gene interaction. Gene‐experience (not gene‐environment) correlations are the rule in human life. Personality disorders co‐occur (are comorbid) with symptom disorders (Axis I) and correlate with common personality dimensions. Possibly, the concept of personality disorder could merge with dysfunctional personality types. But it is likely that the concept will survive on its own.     

A Matter of Context: A Meta‐Analytic Investigation of the Relative Validity of Contextualized and Noncontextualized Personality Measures

The empirical evidence that has accumulated in support of the notion that personality is a valid predictor of employee performance is vast, yet debate on the matter continues. This study investigates frame‐of‐reference effects as they relate to the validity of self‐report measures of personality. Specifically, we compare the validities of general, noncontextualized personality measures and work‐specific, contextualized measures. The findings suggest that personality measures are a more valid predictor of performance when the scale items or instructions are framed specifically so as to reference work‐specific behaviors. We found that the validities for noncontextualized measures of personality ranged from .02 to .22, with a mean validity of .11. The validities for contextualized measures ranged from .14 to .30, with a mean of .24 . Additional moderator analyses were conducted in an effort to examine several alternate explanations for these validity differences. Specifically, we examined differences between the developmental purpose (general use vs. workplace use) and reliabilities of each type of personality measure. We also compared the validities from published studies to those from unpublished studies. Results suggest that these moderators did not have an impact on the validity differences between noncontextualized and contextualized measures.     

Adolescent personality moderates genetic and environmental influences on relationships with parents

In contrast with early theories of socialization that emphasized the role of parents in shaping their children's personalities, recent empirical evidence suggests an evocative relationship between adolescent personality traits and the quality of the parent-adolescent relationship. Research using behavior genetic methods suggests that the association between personality and parenting is genetically mediated, such that the genetic effects on adolescent personality traits overlap with the genetic effects on parenting behavior. In the current study, the authors examined whether the etiology of this relationship might change depending on the adolescent's personality. Biometrical moderation models were used to test for gene- environment interaction and correlation between personality traits and measures of conflict, regard, and involvement with parents in a sample of 2,452 adolescents (M age = 17.79 years). They found significant moderation of both positive and negative qualities of the parent-adolescent relationship, such that the genetic and environmental variance in relationship quality varied as functions of the adolescent's levels of personality. These findings support the importance of adolescent personality in the development of the quality of the parent-adolescent relationship.