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Decades of research have shown that about half of individual differences in personality traits is heritable. Recent studies have reported that heritability is not fixed, but instead decreases across the life span. However, findings are inconsistent and it is yet unclear whether these trends are because of a waning importance of heritable tendencies, attributable to cumulative experiential influences with age, or because of nonlinear patterns suggesting Gene × Environment interplay. We combined four twin samples (N = 7,026) from Croatia, Finland, Germany, and the United Kingdom, and we examined age trends in genetic and environmental variance in the six HEXACO personality traits: Honesty-Humility, Emotionality, Extraversion, Agreeableness, Conscientiousness, and Openness. The cross-national sample ranges in age from 14 to 90 years, allowing analyses of linear and nonlinear age differences in genetic and environmental components of trait variance, after controlling for gender and national differences. The amount of genetic variance in Extraversion, Agreeableness, and Openness followed a reversed U-shaped pattern across age, showed a declining trend for Honesty-Humility and Conscientiousness, and was stable for Emotionality. For most traits, findings provided evidence for an increasing relative importance of life experiences contributing to personality differences across the life span. The findings are discussed against the background of Gene × Environment transactions and interactions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Accurate recognition of others' emotions is an important skill for successful social interaction. Unsurprisingly, it has been an enduring topic of interest, and notable individual differences have been observed. Despite this focus, the underlying functional architecture of this ability has not been thoroughly investigated, particularly concerning emotion recognition across different sensory domains and stimulus modalities. Using a structural equation modelling approach, Study 1 (N = 284) established the structure of emotion recognition ability across three expressive domains – face, body and voice – and observed strong evidence for a superordinate ‘supramodal’ emotion recognition factor, over and above domain-specific factors. Additionally, we observed a significant moderate negative association between this superordinate factor and alexithymia. In Study 2 (N = 218), findings indicated that supramodal emotion recognition ability and face identity recognition are two related but independent constructs. In Study 3 (N = 249), we examined links from both supramodal emotion recognition and face identity recognition to broader cognitive ability, and observed that general intelligence was a significant predictor of supramodal emotion recognition ability. In contrast, there was no association between intelligence and face identity recognition ability. Across three independent samples, then, our findings offer strong support for an emotion recognition ability factor existing across visual and auditory domains encompassing social signals conveyed by face, body and voice, and outline its associations to broader cognitive and affective traits.

A number of studies have reported that higher intelligence is associated with socially liberal attitudes. Less clear, however, is whether this link extends to economic attitudes, although there are indications that higher intelligence is associated with economically conservative attitudes. Here in two large, longitudinal UK cohorts (each N > 7100) we assessed whether childhood intelligence predicted adulthood economic attitudes. In both cohorts we saw that higher levels of childhood (age 10–11) intelligence were related to higher levels of economic conservatism in adulthood (age 30–33). These effects were robust to the inclusion of potential confounders (sex, parental social class, childhood conduct problems). Moreover, this pathway was at least partially mediated by educational attainment and achieved social class/income. These findings confirm the importance of intelligence as an important phenotype for understanding the origins of economic attitudes. Implications for self-interest and rational-interest theories are discussed.

Twin studies of in-group favoritism have reported roughly equal influences of genetic and environmental factors. All, however, have solely relied on cross-sectional approaches, leaving open the question of whether genetic and environmental factors have similar roles on stability and change for in-group favoritism across time. While in-group favoritism is commonly perceived to reflect environmental influences, stable environmental effects are rare for psychological traits, thus suggesting that genetic influences may play the major role in the stability of favoritism. Here, we used addressed this issue using a 10-year (two waves) longitudinal twin design. In-group favoritism showed high rank-order stability ( r = .67). Seventy four percent of this rank-order stability was attributable to genes. A broadly similar pattern was observed for race, ethnic, and religious favoritism. By contrast, changes in favoritism almost entirely reflected nonshared environmental influences. These findings indicate that environmental influences underpin change in favoritism, while the stability of favoritism mostly reflects genetic influences.

BackgroundAlthough behavioural problems (e.g. anxiety, conduct, hyperactivity, peer problems) are known to be heritable both in early childhood and in adolescence, limited work has examined prediction across these ages, and none using a genetically informative sample.MethodWe examined, first, whether parental ratings of behavioural problems (indexed by the Strengths and Difficulties questionnaire) at ages 4, 7, 9, 12, and 16 years were stable across these ages. Second, we examined the extent to which stability reflected genetic or environmental effects through multivariate quantitative genetic analysis on data from a large (n > 3000) population (UK) sample of monozygotic and dizygotic twins.ResultsBehavioural problems in early childhood (age 4 years) showed significant associations with the corresponding behavioural problem at all subsequent ages. Moreover, stable genetic influences were observed across ages, indicating that biological bases underlying behavioural problems in adolescence are underpinned by genetic influences expressed as early as age 4 years. However, genetic and environmental innovations were also observed at each age.ConclusionThese observations indicate that genetic factors are important for understanding stable individual differences in behavioural problems across childhood and adolescence, although novel genetic influences also facilitate change in such behaviours.

This study quantified genetic and environmental roots of variance in prejudice and discriminatory intent toward foreign nationals and examined potential mediators of these genetic influences: right-wing authoritarianism (RWA), social dominance orientation (SDO), and narrow-sense xenophobia (NSX). In line with the dual process motivational (DPM) model, we predicted that the two basic attitudinal and motivational orientations-RWA and SDO-would account for variance in out-group prejudice and discrimination. In line with other theories, we expected that NSX as an affective component would explain additional variance in out-group prejudice and discriminatory intent. Data from 1,397 individuals (incl. twins as well as their spouses) were analyzed. Univariate analyses of twins' and spouses' data yielded genetic (incl. contributions of assortative mating) and multiple environmental sources (i.e., social homogamy, spouse-specific, and individual-specific effects) of variance in negativity toward strangers. Multivariate analyses suggested an extension to the DPM model by including NSX in addition to RWA and SDO as predictor of prejudice and discrimination. RWA and NSX primarily mediated the genetic influences on the variance in prejudice and discriminatory intent toward foreign nationals. In sum, the findings provide the basis of a behavioral genetic framework integrating different scientific disciplines for the study of negativity toward out-groups.

Much of the variation in human personality is described by five to six dimensions. Less clear, however, is whether these dimensions are underpinned by similarly coherent and unified biological bases. Using the HEXACO traits, we tested whether genetic covariance within each dimension was underpinned by a single common genetic factor using three distinct classes of multivariate model. For each of the six factors, only a single common genetic basis was required to explain genetic covariation among the facets, along with facet-specific genetic effects. These findings provide support for personality models positing that the major dimensions of personality are each underpinned by a unified and coherent biological architecture.

In-group favoritism has often been conceptualized as the flip side of out-group derogation. Whereas research has dissociated these attitudes at the phenotypic level, it is currently unknown whether such dissociation is also evident at the biological level. Here, using an adult German twin sample, which provided ratings on patriotism, nationalism, and prejudice, we tested whether common or distinct heritable influences best explained variation in in-group love and out-group derogation. Results indicated that independent genetic effects accounted for individual differences in in-group love (i.e., patriotism) and out-group derogation (i.e., prejudice). In addition, we observed that nationalism showed common genetic links to both patriotism and prejudice, albeit through distinct pathways. These findings suggest that in-group sentiment is complex at the genetic level as well as at the behavioral level. Future work is recommended to further delineate the specific biological processes underlying these heritable effects.

Moral sentiment has been hypothesized to reflect evolved adaptations to social living. If so, individual differences in moral values may relate to regional variation in brain structure. We tested this hypothesis in a sample of 70 young, healthy adults examining whether differences on two major dimensions of moral values were significantly associated with regional gray matter volume. The two clusters of moral values assessed were “individualizing” (values of harm/care and fairness) and “binding” (deference to authority, in-group loyalty, and purity/sanctity). Individualizing was positively associated with left dorsomedial pFC volume and negatively associated with bilateral precuneus volume. For binding, a significant positive association was found for bilateral subcallosal gyrus and a trend to significance for the left anterior insula volume. These findings demonstrate that variation in moral sentiment reflects individual differences in brain structure and suggest a biological basis for moral sentiment, distributed across multiple brain regions.

Behaviour on even simple experimental games shows considerable individual differences, but previous attempts to link these preferences to stable personality traits have had mixed results. Here we address three limitations of earlier studies, namely: (1) uncertainties concerning the reliability of preferences; (2) use of personality instruments with limited cross-study comparability; and (3) confounds where more than one psychological motive can lead to a particular choice. Sixty-seven participants completed 12 distinct real-money games twice over a two-week interval along with 6 measures concerning their expectations about other players' choices. Personality was measured using the full NEO-PI-R. Choices were highly stable across time (r = .84). Moreover, choices on the 12 games and 6 expectations reflected a single underlying dimension of "prosocial orientation", measuring concern for the payoffs received by other players. Scores on the prosocial orientation dimension were related to personality, with openness, (low) neuroticism, and (low) extraversion retained as significant predictors. (C) 2011 Elsevier Ltd. All rights reserved.