Genetic and environmental explanations of juvenile violence in advantaged and disadvantaged environments

This study tests the proposition derived from behavioral genetic theory that genetics and environmental variables have different effects across different environments. I examine the effects of intellectual imbalance [performance IQ (P) significantly greater than verbal IQ (V)] a variable assumed to be heritable to some extent, and love deprivation, a composite variable consisting of various indices of parental abuse and neglect, on violent delinquency within different socioeconomic status (SES) environments. The findings are consistent with behavioral genetic theory, in that love deprivation could not explain any unique variance in violent delinquency after P > V explained all that it could in the advantaged environment (49.5%), and P > V could not explain any unique variance in the disadvantaged environment after love deprivation explained all that it could (28.8%). It was also found that love deprivation explains a highly significant 30.5% of the variance in P > V among SES-disadvantaged subjects, thus supporting those who posit that environmental disadvantages contribute significantly to intellectual imbalance. © 1992 Wiley-Liss, Inc.     

What kind of kind is intelligence?

The model of human intelligence that is most widely adopted derives from psychometrics and behavioral genetics. This standard approach conceives intelligence as a general cognitive ability that is genetically highly heritable and describable using quantitative traits analysis. The paper analyzes intelligence within the debate on natural kinds and contends that the general intelligence conceptualization does not carve psychological nature at its joints. Moreover, I argue that this model assumes an essentialist perspective. As an alternative, I consider an HPC theory of intelligence and evaluate how it deals with essentialism and with intuitions coming from cognitive science. Finally, I highlight some concerns about the HPC model as well, and conclude by suggesting that it is unnecessary to treat intelligence as a kind in any sense.     

The Behavioral Genetics of Religiousness

Behavioral geneticists have sought to characterize the genetic and environmental contributions to individual differences in religiousness. Behavioral genetic methodology is described and twin and adoption studies of religiousness are reviewed. It is concluded that familial resemblance for religiousness is due largely to shared environmental factors in childhood and adolescence, but to genetic factors in adulthood. Additional evidence shows that there is a genetic correlation between religiousness and antisocial and altruistic behavior. Claims for the discovery of a “God gene” are premature and unlikely, as any genetic influence is likely to represent the aggregate effect of many genetic factors.     

Behavioral Genetics, Health, and Aging

A recurring observation from studies of health in the elderly is the pervasiveness of individual differences. For many health-related endpoints, total variation appears to increase across age group; however, few longitudinal studies have reported whether these age differences reflect true age-related changes. There are a growing number of twin studies of aging that provide some insight, at least cross-sectionally, into the nature of individual differences in health. Increases in total variance most often reflect increases in environmental sources of variance. Covariation among traits reflects both genetic and environmental mediation, dependent on the sex of the sample and the measures of interest. Co-twin control approaches have been successful in exploring the role of environmental influences as risk factors for poor health. The most serious limitation to these studies is the lack of longitudinal information to disentangle survival and selection effects from aging.     

The extraversion continuum in evolutionary perspective: A review of recent theory and evidence

We review research on the ultimate and proximate origins of variation along the extraversion continuum. After describing the cost-benefit tradeoffs that may have maintained variation in extraversion over human evolution, we consider the evidence bearing on multiple distinct evolutionary hypotheses regarding the causal underpinnings of such variation. On the basis of the reviewed evidence, we argue that fluctuating selection on specific polymorphic genotypes is unlikely to explain the origins of individual differences in extraversion. Rather, adaptively patterned variation in extraversion is likely orchestrated primarily by facultative adaptations designed to calibrate behavioral strategies to cues available in ontogeny. For example, emerging research supports the hypothesis that extraversion may be “reactively heritable” by virtue of its calibration to heritable condition-dependent phenotypic features – which in turn helps explain extraversion’s genetic variance, as well as its consistent positive association with reproductive success. Finally, evidence suggests that some of the inter-individual variance in extraversion is fundamentally noisy, arising as a side effect of mutation–selection balance or pleiotropic polymorphisms maintained via pathogen–host coevolution. If correct, these conclusions indicate that future research should focus on elucidating the facultative adaptations designed to regulate the production of behaviors falling on the extraversion continuum.     

遗传因素在风险决策加工中的作用

风险决策是指个体对不同选项及其概率进行权衡之后做出决定的过程。它是一个复杂的加工过程, 需要平衡奖赏选项的诱惑和损失选项的忧虑。风险决策能力是人脑最重要的高级功能之一。在现实生活中, 风险决策能力具有非常大的个体差异, 而遗传和环境各自都在其中起着关键的作用。在这篇文章中, 我们首先综述近年来风险决策研究领域中探讨遗传影响风险决策加工的研究, 包括双生子研究与分子遗传学研究。在介绍分子遗传学研究时, 按照基因所属神经递质系统, 分别介绍了多巴胺递质系统相关基因(如COMT、DAT等)、五羟色胺递质系统相关基因(如SLC6A4、TPH1等)和其他基因(如BDNF)对风险决策能力个体差异的影响。随后, 我们探讨了环境对风险决策个体差异的影响, 以及基因-环境交互作用对风险决策个体差异的影响。接下来, 我们介绍了将脑的结构与功能作为内表型来考察基因和环境对风险决策个体差异的影响的最新进展。在文章的最后, 我们指出今后对风险决策个体差异的研究应该同时考虑遗传和环境, 并考察脑的结构和功能在其中的中介作用。     

Personality in the age of industry: Structure,heritability, and correlates of personality in middle childhood from the perspective of parents,teachers, and children

Middle childhood is a crucial juncture in the lifespan where children work toward achieving a sense of competence foundational for future development. However, middle childhood has historically been underrepresented in the personality literature. The current study provides a comprehensive examination of personality in middle childhood using a large (N = 2510), longitudinal sample of 10- to 12-year-old twins. The structure, heritability, and correlates of personality in this period were investigated using personality ratings of parents, teachers, and children. Results showed that personality in middle childhood has a coherent structure, is heritable, and is relevant for developmentally salient outcomes such as externalizing behavior, substance use, and academic engagement. Results emphasize the importance of investigating personality in middle childhood across multiple informants.     

Genetic and environmental stability differs in reactive and proactive aggression

The aim of this study was to examine stability and change in genetic and environmental influences on reactive (impulsive and affective) and proactive (planned and instrumental) aggression from childhood to early adolescence. The sample was drawn from an ongoing longitudinal twin study of risk factors for antisocial behavior at the University of Southern California (USC). The twins were measured on two occasions: ages 9–10 years (N=1,241) and 11–14 years (N=874). Reactive and proactive aggressive behaviors were rated by parents. The stability in reactive aggression was due to genetic and nonshared environmental influences, whereas the continuity in proactive aggression was primarily genetically mediated. Change in both reactive and proactive aggression between the two occasions was mainly explained by nonshared environmental influences, although some evidence for new genetic variance at the second occasion was found for both forms of aggression. These results suggest that proactive and reactive aggression differ in their genetic and environmental stability, and provide further evidence for some distinction between reactive and proactive forms of aggression. Aggr. Behav. 35:437–452, 2009. © 2009 Wiley‐Liss, Inc.     

Genetic and environmental influences on executive functions and intelligence in middle childhood

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated. In twin studies, latent variables for EFs and IQ display moderate to high heritability estimates; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9- to 10-year-olds, including 749 twin pairs) in the Adolescent Brain Cognitive Development (ABCD) Study to examine the phenotypic and genetic relations between EFs and IQ in childhood. We identified two EF factors—Common EF and Updating-Specific—which were both related to IQ (rs = 0.64–0.81). Common EF and IQ were heritable (53%–67%), and their genetic correlation (rG = 0.86) was not significantly different than 1. These results suggest that EFs and IQ are phenotypically but not genetically separable in middle childhood, meaning that this phenotypic separability may be influenced by environmental factors.     

性格优点:创造美好生活的心理资本

性格优点是通过个体的认知、情感和行为而反映出来的一组积极人格特质,它是积极心理学的核心研究领域。研究表明性格优点存在跨文化的普遍性,并且性格优点与优良表现、主观幸福感以及创伤后成长呈显著的正相关。同时,研究表明遗传、年龄、性别以及个体的宗教信仰可能会影响个体性格优点的发展及其表现。文章对性格优点未来的研究方向及其应用进行了探讨。