Face perception across the adult lifespan: evidence for age-related changes independent of general intelligence.

It is well-documented that face perception - including facial expression and identity recognition ability - declines with age. To date, however, it is not yet well understood whether this age-related decline reflects face-specific effects, or instead can be accounted for by well-known declines in general intelligence. We examined this issue using a relatively large, healthy, age-diverse (18-88 years) sample (N = 595) who were assessed on well-established measures of face perception and general intelligence. Replicating previous work, we observed that facial expression recognition, facial identity recognition, and general intelligence all showed declines with age. Of importance, the age-related decline of expression and identity recognition was present even when the effects of general intelligence were statistically controlled. Moreover, facial expression and identity ability each showed significant unique associations with age. These results indicate that face perception ability becomes poorer as we age, and that this decline is to some extent relatively focal in nature. Results are in line with a hierarchical structure of face perception ability, and suggest that age appears to have independent effects on the general and specific face processing levels within this structure.

Consistent evidence of a link between Alexithymia and general intelligence.

Alexithymia is a personality construct characterised most notably by a difficulty in identifying and expressing feelings. Although the emotional difficulties in alexithymia are well established, to date little work has examined its relationship to broader cognitive abilities, such as general intelligence. Across three independent, healthy adult samples (Ns = 389, 318, & 273), we examined whether alexithymia was associated with general intelligence. In all three samples, we observed a significant negative association between alexithymia and general intelligence. In two of the samples, general intelligence was a significant predictor of alexithymia even when accounting for performance on tests of facial emotion recognition ability and supramodal emotion recognition ability (measured with faces, bodies, and voices). From a theoretical perspective, these results suggest that models of alexithymia need to incorporate a role for more generalised cognitive functioning. From a practical perspective, studies examining links between alexithymia and clinical disorders, many of which have known links to general intelligence, should consider including a measure of general intelligence in order to adjust for this potentially confounding factor.

Recognition of facial expression and identity in part reflects a common ability, independent of general intelligence and visual short-term memory.

Recognising identity and emotion conveyed by the face is important for successful social interactions and has thus been the focus of considerable research. Debate has surrounded the extent to which the mechanisms underpinning face emotion and face identity recognition are distinct or share common processes. Here we use an individual differences approach to address this issue. In a well-powered (N = 605) and age-diverse sample we used structural equation modelling to assess the association between face emotion recognition and face identity recognition ability. We also sought to assess whether this association (if present) reflected visual short-term memory and/or general intelligence (g). We observed a strong positive correlation (r = .52) between face emotion recognition ability and face identity recognition ability. This association was reduced in magnitude but still moderate in size (r = .28) and highly significant when controlling for measures of g and visual short-term memory. These results indicate that face emotion and face identity recognition abilities in part share a common processing mechanism. We suggest that face processing ability involves multiple functional components and that modelling the sources of individual differences can offer an important perspective on the relationship between these components.

Widespread associations between trait conscientiousness and thickness of brain cortical regions.

The neural correlates of human personality have been of longstanding interest; however, most studies in the field have relied on modest sample sizes and few replicable results have been reported to date. We investigated relationships between personality and brain gray matter in a sample of generally healthy, older (mean age 73 years) adults from Scotland drawn from the Lothian Birth Cohort 1936. Participants (N = 578) completed a brain MRI scan and self-reported Big Five personality trait measures. Conscientiousness trait scores were positively related to brain cortical thickness in a range of regions, including bilateral parahippocampal gyrus, bilateral fusiform gyrus, left cingulate gyrus, right medial orbitofrontal cortex, and left dorsomedial prefrontal cortex. These associations - most notably in frontal regions - were modestly-to-moderately attenuated by the inclusion of biomarker variables assessing allostatic load and smoking status. None of the other personality traits showed robust associations with brain cortical thickness, nor did we observe any personality trait associations with cortical surface area and gray matter volume. These findings indicate that brain cortical thickness is associated with conscientiousness, perhaps partly accounted for by allostatic load and smoking status.

Early-Childhood Conduct Problems Predict Economic and Political Discontent in Adulthood: Evidence From Two Large, Longitudinal UK Cohorts.

Longstanding interest has been directed toward the etiology of sociopolitical attitudes. Personality traits have been posited as antecedents; however, most work addressing such links has been limited to cross-sectional study designs. The current study used data from two large (both Ns > 8,700), longitudinal cohorts of individuals from the United Kingdom who were parent-assessed on a measure of temperament (assessing anxiety, conduct problems, and hyperactivity) at age 5 or 7 years and on a range of sociopolitical attitudes at age 30 or 33 years. In both cohorts, higher levels of childhood conduct problems predicted higher levels of economic and political discontent in adulthood. These associations were still evident when controlling for sex, childhood intelligence, and parental social class. In both cohorts, this pathway was partially mediated by educational attainment and achieved social class. These findings are consistent with the perspective that early-life temperament gives rise to adult political sentiment.

Externalizing problems in childhood and adolescence predict subsequent educational achievement but for different genetic and environmental reasons.

BACKGROUND: Childhood behavior problems predict subsequent educational achievement; however, little research has examined the etiology of these links using a longitudinal twin design. Moreover, it is unknown whether genetic and environmental innovations provide incremental prediction for educational achievement from childhood to adolescence. METHODS: We examined genetic and environmental influences on parental ratings of behavior problems across childhood (age 4) and adolescence (ages 12 and 16) as predictors of educational achievement at age 16 using a longitudinal classical twin design. RESULTS: Shared-environmental influences on anxiety, conduct problems, and peer problems at age 4 predicted educational achievement at age 16. Genetic influences on the externalizing behaviors of conduct problems and hyperactivity at age 4 predicted educational achievement at age 16. Moreover, novel genetic and (to a lesser extent) nonshared-environmental influences acting on conduct problems and hyperactivity emerged at ages 12 and 16, adding to the genetic prediction from age 4. CONCLUSIONS: These findings demonstrate that genetic and shared-environmental factors underpinning behavior problems in early childhood predict educational achievement in midadolescence. These findings are consistent with the notion that early-childhood behavior problems reflect the initiation of a life-course persistent trajectory with concomitant implications for social attainment. However, we also find evidence that genetic and nonshared-environment innovations acting on behavior problems have implications for subsequent educational achievement, consistent with recent work arguing that adolescence represents a sensitive period for socioaffective development.

Modelling verbal aggression, physical aggression and inappropriate sexual behaviour after acquired brain injury.

Understanding the underpinnings of behavioural disturbances following brain injury is of considerable importance, but little at present is known about the relationships between different types of behavioural disturbances. Here, we take a novel approach to this issue by using confirmatory factor analysis to elucidate the architecture of verbal aggression, physical aggression and inappropriate sexual behaviour using systematic records made across an eight-week observation period for a large sample (n = 301) of individuals with a range of brain injuries. This approach offers a powerful test of the architecture of these behavioural disturbances by testing the fit between observed behaviours and different theoretical models. We chose models that reflected alternative theoretical perspectives based on generalized disinhibition (Model 1), a difference between aggression and inappropriate sexual behaviour (Model 2), or on the idea that verbal aggression, physical aggression and inappropriate sexual behaviour reflect broadly distinct but correlated clinical phenomena (Model 3). Model 3 provided the best fit to the data indicating that these behaviours can be viewed as distinct, but with substantial overlap. These data are important both for developing models concerning the architecture of behaviour as well as for clinical management in individuals with brain injury.

The genetic and environmental roots of variance in negativity toward foreign nationals.

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.

Identical genetic influences underpin behavior problems in adolescence and basic traits of personality.

BACKGROUND: Understanding the etiology of adolescent problem behavior has been of enduring interest. Only relatively recently, however, has this issue been examined within a normal personality trait framework. Research suggests that problem behaviors in adolescence and beyond may be adequately explained by the taxonomy provided by the basic dimensions of normal personality: Such problem behaviors are suggested to be extreme points on a distribution of the full range of the underlying traits. We extend work in this field examining the extent to which genetic factors underlying the five-factor model of personality are common with genetic influences on adolescent behavior problems (namely, anxiety, peer problems, conduct, hyperactivity, and low prosociality). METHOD: A nationally representative twin sample (Twins Early Development Study) from the general population of England and Wales, including 2031 pairs of twins aged 16 years old, was used to decompose variation into genetic and environmental components. Behavioral problems in adolescence were assessed by self-report with the Strengths and Difficulties Questionnaire. RESULTS: Adolescent behavior problems were moderately associated with normal personality: Specifically, a fifth to a third of phenotypic variance in problem behaviors was accounted for by five-factor model personality traits. Of central importance here, genetic influences underpinning personality were entirely overlapping with those genetic factors underlying adolescent behavior problems. CONCLUSIONS: These findings suggest that adolescent behavior problems can be understood, at least in part, within a model of normal personality trait variation, with the genetic bases of these behavior problems the same as those genetic influences underpinning normal personality.

Common heritable effects underpin concerns over norm maintenance and in-group favoritism: evidence from genetic analyses of right-wing authoritarianism and traditionalism.

Research has shown that in-group favoritism is associated with concerns over the maintenance of social norms. Here we present two studies examining whether genetic factors underpin this association. A classical twin design was used to decompose phenotypic variance into genetic and environmental components in two studies. Study 1 used 812 pairs of adult U.S. twins from the nationally representative MIDUS II sample. Study 2 used 707 pairs of middle-age twins from the Minnesota Twin Registry. In-group favoritism was measured with scales tapping preferences for in-group (vs. out-group) individuals; norm concerns were measured with the Multidimensional Personality Questionnaire-Traditionalism (Study 1) and Right-Wing Authoritarianism (RWA; Study 2) scales. In Study 1, heritable effects underlying traditionalism were moderately (c. 35%) overlapping with the genetic variance underpinning in-group favoritism. In Study 2, heritable influences on RWA were entirely shared with the heritable effects on in-group favoritism. Moreover, we observed that Big Five Openness shared common genetic links to both RWA and in-group favoritism. These results suggest that, at the genetic level, in-group favoritism is linked with a system related to concern over normative social practices, which is, in turn, partially associated with trait Openness.

Core dimensions of personality broadly account for the link from perceived social support to symptoms of depression and anxiety.

Specific personality traits and poor social support are risk factors for anxiety and depression. Little work, however, has considered the effects of social support and personality on these aspects of psychopathology simultaneously. We examined whether perceived social support mediates the effects of core personality domains on symptoms of anxiety and depression. Measures of personality (based on the Five-Factor Model [FFM]), perceived social support, and symptoms of depression and anxiety were collected in a large Dutch adult population-based sample (n = 555), and, except for depression symptoms, in an independent U.S. adult population-based sample (n = 511). Path modeling was used to test the effects of FFM traits on symptoms of depression and anxiety, with and without the mediation of perceived social support. Social support showed no link to symptoms of anxiety and only modest links to symptoms of depression when controlling for the FFM traits. Neuroticism had the strongest effect on symptoms of both depression and anxiety, with Extraversion also showing links to symptoms of depression. Social support has limited influence on symptoms of depression, and no effects on anxiety, over and above the effects of personality. Links between social support and anxiety/depression may largely reflect influences of Neuroticism and Extraversion.

Childhood socioeconomic status amplifies genetic effects on adult intelligence.

Studies of intelligence in children reveal significantly higher heritability among groups with high socioeconomic status (SES) than among groups with low SES. These interaction effects, however, have not been examined in adults, when between-families environmental effects are reduced. Using 1,702 adult twins (aged 24-84) for whom intelligence assessment data were available, we tested for interactions between childhood SES and genetic effects, between-families environmental effects, and unique environmental effects. Higher SES was associated with higher mean intelligence scores. Moreover, the magnitude of genetic influences on intelligence was proportional to SES. By contrast, environmental influences were constant. These results suggest that rather than setting lower and upper bounds on intelligence, genes multiply environmental inputs that support intellectual growth. This mechanism implies that increasing SES may raise average intelligence but also magnifies individual differences in intelligence.

Genetic influences on psychological well-being: a nationally representative twin study.

OBJECTIVE: Psychological well-being, or eudaimonia, features strongly in theories of human development and thriving. However, the factors of eudaimonia are debated, and their genetic architecture has not been studied in detail. METHOD: A classical twin design was used to decompose behavioral variance into genetic and environmental components implemented in a multigroup, multivariate structural equation modeling framework. Subjects were 837 pairs of adult U.S. twins from the nationally representative MIDUS II sample. Psychological well-being was measured using the 42-item Ryff Psychological Well-Being Scale, which assesses autonomy, environmental mastery, personal growth, positive relations with others, purpose in life, and self-acceptance. RESULTS: Substantial genetic influences were observed on all components of well-being. Attempts to model these six factors as reflecting a single common psychological mechanism gave a poor fit to the data. The best-fitting model supported the existence of five distinct genetic effects. Effects of shared environment were weak and nonsignificant. Unique environmental effects for all measures were mostly trait specific. CONCLUSIONS: These results indicate that psychological well-being is underpinned by a general genetic factor influencing self-control, and four underlying biological mechanisms enabling the psychological capabilities of purpose, agency, growth, and positive social relations.

Heterogeneous attitudinal profiles towards gene editing: Evidence from latent class analysis.

Advances in gene-editing technology have important implications for the treatment and prevention of disease. Accordingly, it is important to understand public perceptions towards gene editing, as the public's willingness to endorse gene editing may be as important as technological breakthroughs themselves. Previous research has almost exclusively examined attitudes towards gene editing on specific issues, but has not addressed how attitudes towards gene editing across a range of issues coalesce in individuals: that is, the degree to which discrete, heterogeneous attitudinal profiles exist versus a simple support/oppose continuum. Here, we addressed this issue using latent class analysis on data from The Pew Research Center (N = 4726; US residents) across a wide range of gene-editing topics. We found that attitudes towards gene editing cohere into 10 distinct latent classes that showed some evidence of a support/oppose continuum, but also for clear qualitative differences between each class, even with support or oppose classes, on a number of issues. The most opposed classes significantly differed from the supporter classes in age, sex, political ideology and self-rated knowledge. These findings provide evidence that attitudes towards gene editing are heterogeneous and public discourse, as well as policy making need to consider a range of arguments when evaluating this technology.

Moral values are associated with individual differences in regional brain volume.

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.

COVID-19 and seasonal flu vaccination hesitancy: Links to personality and general intelligence in a large, UK cohort.

Vaccines are a powerful and relatively safe tool to protect against a range of serious diseases. Nonetheless, a sizeable minority of people express 'vaccination hesitancy'. Accordingly, understanding the bases of this hesitancy represents a significant public health opportunity. In the present study we sought to examine the role of Big Five personality traits and general intelligence as predictors of vaccination hesitancy across two vaccination types in a large (N = 9667) sample of UK adults drawn from the Understanding Society longitudinal household study. We found that lower levels of general intelligence were associated with COVID-19 and seasonal flu vaccination hesitancy, and lower levels of neuroticism was associated with COVID-19 vaccination hesitancy. Although the self-reported reasons for being vaccine hesitant indicated a range of factors were important to people, lower general intelligence was associated with virtually all of these reasons. In contrast, Big Five personality traits showed more nuanced patterns of association.

A common heritable factor influences prosocial obligations across multiple domains.

Although it has been shown that prosocial behaviour is heritable, it has not yet been established whether narrower aspects of prosociality are heritable, nor whether a common mechanism influences prosociality across its multiple domains. Here, we examine civic duty, work-place commitment and concern for the welfare of others with a study of prosocial obligations in 958 adult twin-pairs. Multivariate modelling indicated the existence of genetic factors underlying general prosocial obligations in females, with familial effects (genetic and shared-environment effects were indistinguishable) influencing this general mechanism in males. At the domain-specific level, modest genetic effects were observed in females for civic and work obligations, with shared-environment effects influencing welfare obligations. In males, genetic influences were observed for welfare obligation, with unique environments affecting work and civic duty.

How genetic and environmental variance in personality traits shift across the life span: Evidence from a cross-national twin study.

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).

Genetic evidence for multiple biological mechanisms underlying in-group favoritism.

In-group favoritism is ubiquitous and associated with intergroup conflict, yet is little understood from a biological perspective. A fundamental question regarding the structure of favoritism is whether it is inflexibly directed toward distinct, "essentialist" categories, such as ethnicity and race, or is deployed in a context-sensitive manner. In this article, we report the first study (to our knowledge) of the genetic and environmental structure of in-group favoritism in the religious, ethnic, and racial domains. We contrasted a model of favoritism based on a single domain-general central affiliation mechanism (CAM) with a model in which each domain was influenced by specific mechanisms. In a series of multivariate analyses, utilizing a large, representative sample of twins, models containing only the CAM or essentialist domains fit the data poorly. The best-fitting model revealed that a biological mechanism facilitates affiliation with arbitrary groups and exists alongside essentialist systems that evolved to process salient cues, such as shared beliefs and ancestry.

Understanding opposition to human gene editing A role for pathogen disgust sensitivity?

Recent advances in gene editing technology promise much for medical advances and human well-being. However, in parallel domains, there have been objections to the use of such biotechnologies. Moreover, the psychological factors that govern the willingness to use gene editing technology have been underexplored to date. In this registered report, we sought to test whether pathogen disgust sensitivity is linked with opposition to gene editing. U.K.-based adult participants (N = 347) were recruited to this study. Gene editing attitudes reflected two largely distinct latent factors concerning enhancing human traits and treating medical disorders. In contrast to prediction, pathogen disgust sensitivity was related to greater support for gene editing in both of these domains. This result suggests that gene editing, at least in the current study, is not viewed as pathogenic, or that the perceived benefits of gene editing outweigh any perceived pathogen risk.