Personality similarity in twins reared apart and together

The Continuity of Adversity: Negative Emotionality Links Early Life Adversity With Adult Stressful Life Events

Adversity that exhibits continuity across the life course has long-term detrimental effects on physical and mental health. Using 920 participants from the Dunedin Study, we tested the following hypotheses: (1) children (ages 3-15) who experienced adversity would also tend to experience adversity in adulthood (ages 32-45), and (2) interim personality traits in young adulthood (ages 18-26) would help account for this longitudinal association. Children who experienced more adversity tended to also experience more stressful life events as adults, β=.11, 95% CI [.04, .18], p=.002. Negative emotionality-particularly its sub-facet alienation, characterized by mistrust of others-helped explain this childhood-to-midlife association (indirect effect: β=.06, 95% CI [.04, .09], p<.001). Results were robust to adjustment for sex, socioeconomic origins, childhood IQ, preschool temperament, and other young-adult personality traits. Prevention of early-life adversity and treatment of young-adult negative emotionality may reduce vulnerability to later life stress and thereby promote the health of aging adults.

A Cross-Sectional Study Investigating Associations between Personality Traits, Glycemic Control, and BMI in Persons with Diabetes: Lolland-Falster Health Study, Denmark

There is a growing focus on person-centered care, emphasizing the importance of respecting inter-individual differences and implementing individualized treatment initiatives. Prior research has established an association between personality traits, body mass index, and health-related behaviors. The aim of this study was to explore the potential of personality trait assessments in identifying individuals at risk of glycemic dysregulation and increasing BMI. This cross-sectional study used a dataset comprising 140 participants with diabetes who completed the Big Five personality trait questionnaire from the Lolland-Falster Health Study. Logistic regression was used to investigate associations between personality traits, glycemic control, and BMI ≥ 25. No significant associations between personality traits and glycemic control were found. There was a significant association between agreeableness and lower odds of BMI ≥ 25 in the unadjusted analysis (OR 0.54 (0.34-0.86)), which persisted after adjusting for sex, age, and education (OR 0.54 (0.33-0.89)). No significant association between glycemic control and personality traits was observed in this small sample study. However, higher levels of agreeableness were associated with a lower likelihood of having a BMI of ≥25. This preliminary study suggests that integrating personality assessments could help identify individuals at risk of increasing BMI. These findings highlight the potential of using personality traits to guide targeted interventions, offering a direction for future research.

The education-health gradient: Revisiting the role of socio-emotional skills

Is the education-health gradient inflated because both education and health are associated with unobserved socio-emotional skills? We find that the gradient in health behaviors and outcomes is reduced by about 15 to 50% from accounting for fine-grained personality facets and up to another 50% from Locus of Control. Traditional aggregated Big-Five scales, however, have a much smaller contribution to the gradient. We use sibling-fixed effects to net out the contribution from genes and shared childhood environment, decomposing the gradient into its components with an order-invariant method. We rely on a large survey (N = 28,261) linked to high-quality Danish administrative registers with information on parental background and objectively measured diagnoses and care use. Accounting for Locus of Control yields the strongest gradient reduction in self-rated health status and objective diagnoses (30%-50%), and in health behaviors the most important factor is Extraversion, a skill that has been shown to be malleable in interventions.

An examination of the relationship between sport performers' organizational stressor dimensions, physical health, and well-being

Whilst research has assessed the multidimensionality of organizational stressors, severity has been overlooked. This study aimed to develop and validate a severity response scale, before examining the relationship between organizational stressor severity, physical health, and well-being, and if severity mediated the relationship between stressor occurrence and outcomes. 403 sport performers (186 male; Mage = 21.43) completed a questionnaire assessing study variables and data were analysed using structural equation modelling. Organizational stressor severity had a significant, negative relationship with physical health (r = -.374, p < .001), but notwith hedonic or eudaimonic well-being (p = .624 and .203). Direct effects were found for neuroticism (β = -0.632, p < .001) and stressor frequency (β = -0.226, p = .016) on physical health; however, when adding severity as a mediator, stressor frequency positively predicted stressor severity (β = 1.025, p < .001); however, the indirect effect of stressor frequency on physical health via stressor severity (β = -0.018, p = .885) and the direct effect between stressor frequency and physical health (β = -0.191, p = .204) were non-significant. These novel findings highlight that higher stressor severity is associated with higher physical health complaints, and that repeated exposure to stressors may heighten an vulnerability to future stressors.

Executive Function as an Underlying Mechanism of Alcohol Use, Aggression, and ADHD

Background

Executive functioning (EF) has been proposed as a transdiagnostic risk factor for externalizing disorders and behavior more broadly, including attention-deficit/hyperactivity disorder (ADHD), aggression, and alcohol use. Previous research has demonstrated both phenotypic and genetic overlap among these behaviors, but has yet to examine EF as a common causal mechanism. The current study examined reciprocal causal associations between EF and several externalizing behaviors using a Mendelian randomization (MR) approach.

Methods

Two-sample MR was conducted to test causal associations between EF and externalizing behaviors. Summary statistics from several genome-wide association studies (GWASs) were used in these analyses, including GWASs of EF, ADHD diagnostic status, drinks per week, aggressive behavior, and alcohol use disorder (AUD) diagnostic status. Multiple estimation methods were employed to account for horizontal pleiotropy (e.g., inverse variance weighted, MR-PRESSO, MR-MIX).

Results

EF demonstrated significant causal relationships with ADHD (P < 0.01), AUD (P < 0.03), and alcohol consumption (P < 0.01) across several estimation methods. Reciprocally, ADHD showed a significant causal influence on EF (P < 0.03). Nonetheless, caution should be used when interpreting these findings as there was some evidence for horizontal pleiotropy in the effect of EF on ADHD and significant heterogeneity in variant effects in the other relations tested. There were no significant findings for aggression.

Conclusions

Findings suggest that EF may be a causal mechanism underlying some externalizing behaviors, including ADHD and alcohol use, and that ADHD may also lead to lower performance on EF tasks.

Affect and satisfaction time dependency: An experience sampling study

The aim of this study was to test the time dependency between affect and satisfaction on a momentary level. Ninety-eight students participated in the study, using the experience sampling method. Affect and satisfaction scales were administered five times a day for 7 days via handheld devices, sampling the whole awake period with ratings approximately 3-4 h apart. The aim of this study was to examine the cross-correlation between affect and satisfaction at the intra-individual level and to test their temporal consistency via lagged cross-correlations. On average, satisfaction was robustly associated with positive affect (PA; mean correlation 0.50) and negative affect (NA; mean correlation -0.38). The correlation of satisfaction with affect factors showed a consistent temporal dependency. Lag (i.e., the shift of one time series with respect to another) significantly affected the magnitude of the correlation coefficients of satisfaction with PA and NA (explaining almost half of the correlation variance). A significant affect-satisfaction cross-correlation can be found when no lag is present. The introduction of a lag reduces the affect-satisfaction cross-correlation to virtually zero. Research suggests that affect and satisfaction overlap at the momentary level, and the results of this study imply that they are also time-dependent. These findings corroborate the idea that momentary satisfaction judgments are partially based on available emotional information, both in terms of intensity and temporal consistency.

Association between personality traits and smoking cessation among Chinese adults

BACKGROUND

Although the tobacco epidemic is one of the greatest public health threats, the smoking cessation rate among Chinese adults is considerably lower. Personality information may indicate which treatments or interventions are more likely to be effective. China is the largest producer and consumer of tobacco worldwide. However, little is known about the association between smoking cessation and personality traits in China.

AIM

This study aimed to examine the association between successful smoking cessation and personality traits among Chinese adults.

METHODS

This cross-sectional study used data from the 2018 China Family Panel Studies. Probit regression models were employed to analyze the association between successful smoking cessation and personality traits stratified by sex.

RESULTS

Lower scores for neuroticism (Coef.=-0.055, p < 0.1), lower scores for extraversion (Coef.=-0.077, p < 0.05), and higher scores for openness to experience (Coef.=0.045, p < 0.1) predicted being a successful male quitter after adjusting for demographics. Moreover, lower scores for conscientiousness (Coef.=-0.150, p < 0.1) predicted being a successful female quitter after adjusting for demographics.

CONCLUSION

The empirical findings suggested that among Chinese men, lower levels of neuroticism, lower levels of extraversion, and higher levels of openness to experience were associated with a higher likelihood of smoking cessation. Moreover, lower levels of conscientiousness were associated with successful smoking cessation among Chinese women. These results showed that personality information should be included in smoking cessation interventions.

How can the DSM-5 alternative model of personality disorders advance understanding of depression?

BACKGROUND

The DSM-5 introduced an alternative model of personality disorder (AMPD) that includes personality dysfunction plus maladaptive-range traits. This study clarifies relations of depression diagnoses and symptoms with AMPD personality pathology.

METHOD

Two samples (Ns 402 and 601) of outpatients and community-dwelling adults completed four depression (criteria met for major depressive disorder and dysthymia; dysphoria and low well-being scales), ten trait (two scales for each of five domains-negative affectivity, detachment, disinhibition, antagonism, psychoticism), and eight dysfunction (four scales for each of two domains-self- and interpersonal pathology) measures. Diagnoses were made using a semi-structured interview; other measures were self-reports. We quantified cross-sectional relations between depression and personality pathology with correlation and multiple regression analyses.

RESULTS

Collectively (median R²; ps < 0.0001), the trait (0.46) and dysfunction (0.50) scales predicted the depression measures strongly, with most predictive power shared (0.41) between traits and dysfunction. However, trait and dysfunction scales altogether predicted depression (median R² = 0.54) more strongly than either domain alone, ps < 0.0001. Participants with depression diagnoses showed elevations on all nonadaptive trait and personality dysfunction measures, particularly negative temperament/affectivity and self-pathology measures.

LIMITATIONS

Generalization of findings to other populations (e.g., adolescents), settings (e.g., primary care), and measures (e.g., traditional personality disorder diagnoses) is uncertain. Cross-sectional analyses did not test changes over time or establish causality.

CONCLUSIONS

The AMPD is highly relevant to depression. Assessment of personality pathology, including both personality dysfunction and maladaptive-range traits, stands to advance understanding of depression in adults.

Research on the effects of family rituals on subjective well-being of Chinese college students

Faced with multiple pressures from family, study, employment and interpersonal relationship management, college students are more likely to suffer from mental health problems. At present, psychological intervention in China mainly focuses on drugs and interviews, ignoring the important role played by the family as a bio-psycho-social unit, and there are certain cultural compatibility differences. As an important activity in family life, family rituals have been widely used in the treatment of diseases or mental health in western countries. In contrast, in China, the public's attention and application of family rituals are obviously insufficient, and the relevant academic research results are relatively rare. In view of this, this paper adopts mathematical statistics method to clarify the internal relationship between family rituals and subjective well-being of college students, and verify the mediating role of family system in it, so as to provide effective suggestions for psychological health intervention of college students. The results showed that: Family rituals, family system and subjective well-being are correlated in pairs, showing a significant positive correlation; Family rituals and family system have significant predictive effects on subjective well-being of college students; The cohesion and adaptability play part of mediating roles between college students' family rituals and subjective well-being.

Regional well-being inequalities arising from healthcare expenditure public policies in Spain

Well-being inequalities arising from different healthcare expenditure public policies is currently a hot topic at a national scale, but especially so at a sub-national level because the inequalities in question are among citizens of the same country. Spain is an optimal study area to carry out research on this topic because it is considered to have one of the best health systems in the world, it is one of the top-ranking countries in terms of life expectancy rates (the indicators we use for well-being), and it has a decentralized public health system with significantly different regional healthcare expenditure public policies. Given that the factors involved in the complex direct, indirect, and second-order relationships between well-being and health spending are latent in nature, and that there are more hypotheses than certainties regarding these relationships, we propose a partial least squares structural equation modeling specification to test the research hypotheses and to estimate the corresponding impacts. These constructs are proxied by a set of 26 indicators, for which annual values at a regional scale were used for the period 2005-2018. From the estimation of this model, it can be concluded that mortality, expenditure and resources are the factors that have the greatest impact on well-being. In addition, a cluster analysis of the indicators for the constructs included in this research reveals the existence of three clearly differentiated groups of autonomous communities: the northern part of the country plus Extremadura (characterized by the lowest well-being and the highest mortality rates), Madrid (with the best results in well-being and mortality, the lowest public health expenditure per inhabitant and percentage of pharmaceutical spending, and the highest percentage in specialty care services and medical staff spending), and the rest of the country (south-eastern regions, with similar well-being values to those of the first group but with less health expenditure). Finally, a principal component analysis reveals that "healthiness" and "basic spending" are the optimal factors for mapping well-being and health spending in Spain.

Independent phenotypic plasticity axes define distinct obesity sub-types

Studies in genetically 'identical' individuals indicate that as much as 50% of complex trait variation cannot be traced to genetics or to the environment. The mechanisms that generate this 'unexplained' phenotypic variation (UPV) remain largely unknown. Here, we identify neuronatin (NNAT) as a conserved factor that buffers against UPV. We find that Nnat deficiency in isogenic mice triggers the emergence of a bi-stable polyphenism, where littermates emerge into adulthood either 'normal' or 'overgrown'. Mechanistically, this is mediated by an insulin-dependent overgrowth that arises from histone deacetylase (HDAC)-dependent β-cell hyperproliferation. A multi-dimensional analysis of monozygotic twin discordance reveals the existence of two patterns of human UPV, one of which (Type B) phenocopies the NNAT-buffered polyphenism identified in mice. Specifically, Type-B monozygotic co-twins exhibit coordinated increases in fat and lean mass across the body; decreased NNAT expression; increased HDAC-responsive gene signatures; and clinical outcomes linked to insulinemia. Critically, the Type-B UPV signature stratifies both childhood and adult cohorts into four metabolic states, including two phenotypically and molecularly distinct types of obesity.

Well-Being Science for Teaching and the General Public

Research on well-being has exploded in recent years to more than 55,000 relevant publications annually, making it difficult for psychologists-including key communicators such as textbook authors-to stay current with this field. Moreover, well-being is a daily concern among policymakers and members of the general public. Well-being science is relevant to the lives of students-illustrating the diverse methods used in the behavioral sciences, presenting highly replicated findings, and demonstrating the diversity of individuals and cultures. Therefore, in this article, we present eight major findings that teachers and authors should seriously consider in their coverage of this field. These topics include processes such as adaptation, influences such as income, the benefits of well-being, and cultural and societal diversity in well-being and its causes. We also examine how much these topics were covered in 15 of the most popular introductory psychology textbooks. Although some topics such as social relationships and well-being were discussed in nearly all textbooks, others were less frequently covered, including the validity of self-reported well-being, the effects of spending on happiness, and the impact of culture and society on well-being. We aim to ensure more complete coverage of this important area in psychology courses.

Significance-Quest Theory

Even though the motivation to feel worthy, to be respected, and to matter to others has been identified for centuries by scholars, the antecedents, consequences, and conditions of its activation have not been systematically analyzed or integrated. The purpose of this article is to offer such an integration. We feature a motivational construct, the quest for significance, defined as the need to have social worth. This need is typically fulfilled by a sense of measuring up to the values one shares with significant others. Our significance-quest theory (SQT) assumes that the need for significance is universal, whereas the means of satisfying it depend on the sociocultural context in which one's values are embedded. Those means are identified in a narrative supported and validated by one's network, or reference group. The quest for significance is activated by significance loss and/or the opportunity for significance gain. It motivates behavior that aims to affirm, realize, and/or show commitment to an important value. The SQT is consistent with large bodies of prior research and supported by novel studies in multiple laboratory and field settings. It transcends prior understandings and offers guidance for further study of this essential human motivation.

A Multivariate Study of Human Mate Preferences: Findings from the California Twin Registry

Much research examining the biological and social-cultural underpinnings of human mate preferences has focused on univariate or bivariate analyses of demographic variables and personality constructs. In this paper, we argue that a multivariate approach more effectively highlights the multifaceted structure and correlates of human mate preferences. To support this claim, we applied several multivariate techniques to data from a large adult sample to (1) examine the major dimensions underlying individual differences in mate preferences, and (2) elucidate how these preferences relate to individual differences in personality. An exploratory factor analysis of an omnibus mate preference questionnaire yielded a 14-factor solution with dimensions mirroring trends in evolutionary psychology and the Big Five personality framework. An inter-battery factor analysis of these dimensions paired with higher-order personality factors provided strong support for the "likes attract" model of partner preferences. Bootstrap confidence intervals for all factor loadings highlighted the robustness of our results.

Twins Separated at Birth: Across a Country and Around the World/Twin Research: Memorial Tribute to Isaac Blickstein, MD; Infanticide and Sacrifice of Archaic-Aged Twins and Triplets; Prehistoric Twin Burials; Highlights from a Conference on Three Identical Strangers/Media Reports: An Atypical Twin Father; An Actor's Twin Brother; Twin Link to Tulsa, Oklahoma Massacre; Superfetated Twins; Twin Comedians and Script Writers; Indian Twins' Loss to COVID-19

Every reared-apart monozygotic (MZ) twin pair offers a fresh perspective on human developmental questions. This is true regardless of whether the co-twins were raised in the same country or across the globe. The members of two pairs of separated MZ female twins have recently come to attention. In one case the twins were raised by different families in Argentina; in the other case the twins were raised by different families in Sweden and Vietnam. The perceptions and perspectives of these twins are insightful. The twin research section that follows begins with a tribute to our late esteemed colleague, Dr Isaac Blickstein (1953-2020). Research concerning the infanticide and sacrifice of Archaic-aged twins and triplets and prehistoric twin burials is reviewed next. Highlights from a conference focused on the 2018 film Three Identical Strangers are also included in this portion. The final section of this article includes media reports of an atypical twin father, an actor's twin brother, a twin link to the 1921 Tulsa, Oklahoma massacre, the birth of superfetated twins, twin comedians and script writers and Indian twins' tragic loss to COVID-19.

Dignity neuroscience: universal rights are rooted in human brain science

Universal human rights are defined by international agreements, law, foreign policy, and the concept of inherent human dignity. However, rights defined on this basis can be readily subverted by overt and covert disagreements and can be treated as distant geopolitical events rather than bearing on individuals’ everyday lives. A robust case for universal human rights is urgently needed and must meet several disparate requirements: (1) a framework that resolves tautological definitions reached solely by mutual, revocable agreement; (2) a rationale that transcends differences in beliefs, creed, and culture; and (3) a personalization that empowers both individuals and governments to further human rights protections. We propose that human rights in existing agreements comprise five elemental types: (1) agency, autonomy, and self‐determination; (2) freedom from want; (3) freedom from fear; (4) uniqueness; and (5) unconditionality, including protections for vulnerable populations. We further propose these rights and protections are rooted in fundamental properties of the human brain. We provide a robust, empirical foundation for universal rights based on emerging work in human brain science that we term dignity neuroscience. Dignity neuroscience provides an empirical foundation to support and foster human dignity, universal rights, and their active furtherance by individuals, nations, and international law.

DNA methylation signatures of aggression and closely related constructs: A meta-analysis of epigenome-wide studies across the lifespan

DNA methylation profiles of aggressive behavior may capture lifetime cumulative effects of genetic, stochastic, and environmental influences associated with aggression. Here, we report the first large meta-analysis of epigenome-wide association studies (EWAS) of aggressive behavior (N = 15,324 participants). In peripheral blood samples of 14,434 participants from 18 cohorts with mean ages ranging from 7 to 68 years, 13 methylation sites were significantly associated with aggression (alpha = 1.2 × 10-7; Bonferroni correction). In cord blood samples of 2425 children from five cohorts with aggression assessed at mean ages ranging from 4 to 7 years, 83% of these sites showed the same direction of association with childhood aggression (r = 0.74, p = 0.006) but no epigenome-wide significant sites were found. Top-sites (48 at a false discovery rate of 5% in the peripheral blood meta-analysis or in a combined meta-analysis of peripheral blood and cord blood) have been associated with chemical exposures, smoking, cognition, metabolic traits, and genetic variation (mQTLs). Three genes whose expression levels were associated with top-sites were previously linked to schizophrenia and general risk tolerance. At six CpGs, DNA methylation variation in blood mirrors variation in the brain. On average 44% (range = 3-82%) of the aggression-methylation association was explained by current and former smoking and BMI. These findings point at loci that are sensitive to chemical exposures with potential implications for neuronal functions. We hope these results to be a starting point for studies leading to applications as peripheral biomarkers and to reveal causal relationships with aggression and related traits.

Psychological Bases of Symptom Reporting: Perceptual and Emotional Aspects of Chemical Sensitivity

The reporting of physical symptoms is influenced to a large degree by psychological processes. Individuals are more likely to notice subtle sensations in environments lacking in stimulation than those demanding external attention. The beliefs or schemas that people hold dictate where and how they attend to their bodies as well. These normal perceptual processes help explain why people are of ten poor at accurately detecting internal physiological activity. Several individual differences are also related to the symptom reporting process. Females are more likely to base their symptom reports on external situational cues than are males. In addition, individuals with chronic anxiety those high in Negative Affectivity (NA) report more symptoms than those low in NA. Finally, individuals who have had traumatic experiences, either in childhood or within 16 months prior to a major symptom reporting episode, tend to be high symptom reporters. Several recommendations are made to help researchers and clinicians distinguish between psychological or perceptual factors with presumed biological effects. One implication of this work is that MCS and allied syndromes should be viewed as both a mental and a physical health problem.

Neurobiological factors in personality and depression

There is very little empirical work that directly assesses the neurobiological association of personality superfactors with the liability to depression. Therefore, as a means of providing a framework for future research, this article outlines the putative neurobiological foundation of three major personality superfactors: positive emotionality or extraversion, constraint or psychoticism, and negative emotionality or neuroticism. The neurobiology of these superfactors, particularly the central dopamine, serotonin, and norepinephrine projection systems, respectively, is derived largely from animal biobehavioral research, although human work is discussed where available. In an attempt to explore the association of this framework to depression, extreme quantitative variation in the resulting neurobiological systems, alone and in interaction with each other, is discussed in terms of different forms of depression and of modification of the phenotype and course of depression. The effects of experience on neurobiological functioning is briefly considered as a therapeutic approach, in lieu of, or in interaction with, pharmacological modulation of behavior.

Personality and depression: A multilevel perspective

In personality psychology, depression is currently studied from different, largely unrelated, perspectives. This paper argues that our understanding of complex phenomena such as depression may benefit from a multilevel approach, ordering and connecting the findings obtained at different levels of inquiry. Not only can findings at a particular level be explained in terms of the lower levels, but this approach can also provide a framework for integration. Depression is examined at different levels, including genes, neurology, biochemistry, physiology, learning, social behaviour, and traits. Several interlevel connections are indicated. The findings are discussed in the context of self‐regulation as a general framework.

Constructive thinking as a mediator of the relationship between extraversion, neuroticism, and subjective well‐being

Mechanisms by which personality affects well‐being are not well understood. Following recommendations to examine intermediate process variables that may help explain the personality–subjective well‐being (SWB) relationship, the authors tested whether constructive thinking (CT) mediated the relationships between both neuroticism and extraversion and SWB components. Measures of each construct were administered to 147 undergraduate volunteers twice over four weeks. In analyses controlling for time 1 SWB and time 2 mood, time 2 CT fully mediated the relationship between time 1 neuroticism and time 2 negative affect and emerged as a strong predictor of negative affect (inversely), positive affect, and happiness. Copyright © 2005 John Wiley & Sons, Ltd.

Children's temperament in the US and China: similarities and differences

We report the results of research investigating temperamental characteristics of children in the People's Republic of China and the US using a parent‐report instrument, the Children's Behavior Questionnaire (CBQ), defining temperament as individual differences in emotional, motoric, and attentional reactivity and self‐regulation. Subjects were 624 6‐ to 7‐year‐old children, from Shanghai and the north‐western region of the US. The 15 CBQ scales were factored for both samples, employing a principal axis factor analysis with an oblique rotation. Our findings indicated considerable similarity of factor structure in the two cultures, obtaining three factors labelled Surgency, Negative Affect, and Attentional Self‐Regulation or Effortful Control. Differences across cultures were also found, with Surgency and Effortful Control scores being relatively higher than Negative Affect in the US sample and Negative Affect being relatively higher than Surgency and Effortful Control in the Chinese sample. Gender differences were also found to vary across cultures. Our findings are congruent with a view of underlying cultural similarities in temperamental variability across these cultures, influenced over time by the children's culturally varied experience.

Trait explanations in personality psychology

Recent debates on the status of contemporary trait psychology (Pervin, 1994) have revived old questions about the role of traits in the explanation of behavior: are traits mere descriptions of behavior, or do they offer one legitimate and useful form of explanation? We review the logic of trait explanation and present a general model of the person in which personality traits are hypothetical constructs regarded as basic dispositions. In interaction with external influences—notably shared meaning systems—traits contribute causally to the development of habits, attitudes, skills, and other characteristic adaptations. In this model, action and experience can be explained directly or proximally in terms of the interaction of the immediate situation with the individual's characteristic adaptations, and indirectly or distally in terms of underlying personality traits.

The adaptive value of personality differences revealed by small island population dynamics

Whether differences in personality among populations really exist and, if so, whether they are only due to cultural and linguistic differences or have a genetically selected adaptive value, is a controversial issue. In this research, we compared three Italian populations living on three small archipelagos in the Tyrrhenian Sea (n = 993), with their corresponding neighbouring mainlanders (n = 598), i.e. sharing the same geographical origin, culture and language. We used an adjective‐based Big Five questionnaire in order to measure personality traits in four categories of individuals for each archipelago/mainland population: (1) original islanders; (2) non‐original islanders; (3) mainlanders and (4) immigrants to the islands. We further analysed original and non‐original islanders who had or had not emigrated from the islands. We found that islanders had different personality traits from mainlanders, the former being more conscientious and emotionally stable and less extraverted and open to experience. We also found that the subgroup of islanders whose ancestors had inhabited their island for about 20 generations in isolation (original islanders, n = 624) were less extraverted and open to experience than immigrants (n = 193). In contrast, immigrants retained the typical personality profile of the mainland populations. Lastly, emigrants from the islands (n = 209) were significantly more extraverted and open to experience than original and non‐original islanders who had never left their island (n = 741). We hypothesise that population differences in extraversion and openness to experience are more probably related to genetic differences which evolved rapidly, presumably through an active gene flow produced by selective emigration from the islands. Copyright © 2006 John Wiley & Sons, Ltd.

Transdiagnostic treatment of emotional disorders in people with multiple sclerosis: randomized controlled trial

BACKGROUND

Multiple sclerosis (MS) is a neurodegenerative disease of the central nervous system. MS is significantly associated with a high rate of psychological, behavioral, and emotional consequences. Despite the frequent mental disorders, high rate of psychological comorbidities, and emotional problems in people with MS (PwMS), these conditions are often underdiagnosed and undertreated. This study aimed to examine the efficacy of a group format of the unified protocol for the transdiagnostic treatment of emotional disorders in adult PwMS associated with an emotional disorder.

METHODS

Seventy adult PwMS were randomized using an internet-based computer system to either the unified protocol (n = 35) or treatment as usual condition. The assessment protocol included semi-structured clinical interviews and self-reports evaluating diagnostic criteria, depression, anxiety and worry symptoms, emotional dysregulation, and affectivity.

RESULTS

The parametric test of analysis of covariance, followed the intent to treat analyses, revealed the unified protocol significantly changed depression symptoms (Cohen's d = 1.9), anxiety symptoms (Cohen's d = 2.16), worry symptoms (Cohen's d = 1.27), emotion dysregulation (Cohen's d = 0.44), positive affect (Cohen's d = 1.51), and negative affect (Cohen's d = 1.89) compared with the control group. The unified protocol also significantly improved outcome scores at the end of treatment relative to baseline (p < .001).

CONCLUSION

The findings support that the unified protocol could be an additional efficient psychological treatment for PwMS. Trial registration IRCT, number: IRCT20190711044173N1. Registered 31october 2019, https://en.irct.ir/user/trial/40779/view .

Transdiagnostic treatment of emotional disorders for women with multiple sclerosis: a randomized controlled trial

BACKGROUND

Multiple sclerosis (MS) is a chronic, unpredictable, neurodegenerative disease, significantly associated with psychological, behavioral, cognitive, and emotional consequences. MS is more common in females than males and frequently affects women during their reproductive years. Despite the frequent mental disorders, comorbidities, and emotional problems in People with MS (PwMS), these conditions are too often underdiagnosed and undertreated.

OBJECTIVE

This study aimed to examine the efficacy of a group format of the Unified Protocol (UP) for the Transdiagnostic treatment of depression and anxiety disorders in females with MS.

METHODS

In the present study, Sixty-four adult females diagnosed with MS were randomized to either the UP (n = 32) or treatment-as-usual conditions. The assessment protocol included semi-structured clinical interviews and self-reports evaluating diagnostic criteria, depression, anxiety and worry symptoms, emotional regulation, and affectivity.

RESULTS

Repeated measure analysis of variance (ANOVA) revealed that the UP significantly improved depression scores [Cohen's d = - 2.11, 95% CI (- 2.72, - 1.50)], anxiety scores [Cohen's d = - 3.34, 95% CI (- 4.01, - 2.58)], positive and negative affect scale (PANAS)-positive affect scores [Cohen's d = 1.46, 95% CI (1.46, 2.01)], PANAS-negative affect scores [Coen's d = - 2.21, 95% CI (- 2.84, - 1.60)], difficulties emotion regulation scale scores [Cohen's d = 1.40, 95% CI (- 0.87, - 0.03)], and Worry scale scores [Cohen's d = - 0.45, 95% CI (- 0.95, - 0.04)] at the end of treatment relative to compared to the control condition. Also, treatment gains were maintained at the three-month follow-up (p < 0.001).

CONCLUSION

The findings provide the support that the UP could be an additional efficient psychological treatment for females with MS. ISRCTN Number: ISRCTN95459505.

Transdiagnostic treatment of emotional disorders in people with multiple sclerosis: randomized controlled trial

Background

Multiple sclerosis (MS) is a neurodegenerative disease of the central nervous system. MS is significantly associated with a high rate of psychological, behavioral, and emotional consequences. Despite the frequent mental disorders, high rate of psychological comorbidities, and emotional problems in people with MS (PwMS), these conditions are often underdiagnosed and undertreated. This study aimed to examine the efficacy of a group format of the unified protocol for the transdiagnostic treatment of emotional disorders in adult PwMS associated with an emotional disorder.

Methods

Seventy adult PwMS were randomized using an internet-based computer system to either the unified protocol (n = 35) or treatment as usual condition. The assessment protocol included semi-structured clinical interviews and self-reports evaluating diagnostic criteria, depression, anxiety and worry symptoms, emotional dysregulation, and affectivity.

Results

The parametric test of analysis of covariance, followed the intent to treat analyses, revealed the unified protocol significantly changed depression symptoms (Cohen’s d = 1.9), anxiety symptoms (Cohen’s d = 2.16), worry symptoms (Cohen’s d = 1.27), emotion dysregulation (Cohen’s d = 0.44), positive affect (Cohen’s d = 1.51), and negative affect (Cohen’s d = 1.89) compared with the control group. The unified protocol also significantly improved outcome scores at the end of treatment relative to baseline (p < .001).

Conclusion

The findings support that the unified protocol could be an additional efficient psychological treatment for PwMS.

Trial registration IRCT, number: IRCT20190711044173N1. Registered 31october 2019, https://en.irct.ir/user/trial/40779/view.

The neurobiology of wellness: 1H-MRS correlates of agency, flexibility and neuroaffective reserves in healthy young adults

Proton magnetic resonance spectroscopy (¹H-MRS) is a noninvasive imaging technique that measures the concentration of metabolites in defined areas of the human brain in vivo. The underlying structure of natural metabolism-emotion relationships is unknown. Further, there is a wide range of between-person differences in metabolite concentration in healthy individuals, but the significance of this variation for understanding emotion in healthy humans is unclear. Here we investigated the relationship of two emotional constructs, agency and flexibility, with the metabolites glutamate and glutamine (Glx), N-acetylaspartate (tNAA), choline (Cho), creatine (tCr), and myo-inositol (Ins) in the right dorsal anterior cingulate cortex (dACC) in medically and psychiatrically healthy volunteers (N = 20, 9 female; mean age = 22.8 years, SD = 3.40). The dACC was selected because this region is an integrative hub involved in multiple brain networks of emotion, cognition and behavior. Emotional traits were assessed using the Multidimensional Personality Questionnaire Brief Form (MPQ-BF), an empirically derived self-report instrument with an orthogonal factor structure. Phenotypes evaluated were positive and negative agency (MPQ-BF Social Potency, Aggression), emotional and behavioral flexibility (MPQ-BF Absorption, Control-reversed), and positive and negative affect (MPQ-BF Social Closeness; Stress Reaction, Alienation). The resting concentration of tNAA in the dACC was robustly positively correlated with Absorption (r = +0.56, unadjusted p = .005), moderately positively correlated with Social Potency (r = +0.42, unadjusted p = .03), and robustly negatively correlated with Aggression (r = −0.59, unadjusted p = .003). Absorption and Aggression accounted for substantial variance in tNAA (R² = 0.31, 0.35; combined R² = 0.50), and survived correction for multiple comparisons (Holm-Bonferroni adjusted p = .032, 0.021, respectively). dACC Glx and Cho had modest relationships with behavioral flexibility and social affiliation that did not survive this multiple correction, providing effect sizes for future work. Principal Component Analysis (PCA) revealed a three-factor orthogonal solution indicating specific relationships between: 1) Glx and behavioral engagement; 2) Cho and affiliative bonding; and 3) tNAA and a novel dimension that we term neuroaffective reserves. Our results inform the neurobiology of agency and flexibility and lay the groundwork for understanding mechanisms of natural emotion using ¹H-MRS.

Toward Multimodal Modeling of Emotional Expressiveness

Emotional expressiveness captures the extent to which a person tends to outwardly display their emotions through behavior. Due to the close relationship between emotional expressiveness and behavioral health, as well as the crucial role that it plays in social interaction, the ability to automatically predict emotional expressiveness stands to spur advances in science, medicine, and industry. In this paper, we explore three related research questions. First, how well can emotional expressiveness be predicted from visual, linguistic, and multimodal behavioral signals? Second, how important is each behavioral modality to the prediction of emotional expressiveness? Third, which behavioral signals are reliably related to emotional expressiveness? To answer these questions, we add highly reliable transcripts and human ratings of perceived emotional expressiveness to an existing video database and use this data to train, validate, and test predictive models. Our best model shows promising predictive performance on this dataset (RMSE = 0.65, R 2 = 0.45, r = 0.74). Multimodal models tend to perform best overall, and models trained on the linguistic modality tend to outperform models trained on the visual modality. Finally, examination of our interpretable models' coefficients reveals a number of visual and linguistic behavioral signals-such as facial action unit intensity, overall word count, and use of words related to social processes-that reliably predict emotional expressiveness.

Occlusal Features and TMJ Clicking: A 30-Year Evaluation from a Cohort Study

Occlusal features that deviate from normative values have been historically considered risk factors for temporomandibular joint (TMJ) disorders. Nowadays, a putative association between dental occlusion and TMJ disorders remains controversial, with research findings on associations being inconsistent and inconclusive. We hypothesized that putative occlusal features identified during adolescence are associated with TMJ clicking later in life. The Dunedin Multidisciplinary Health and Development Study is a longitudinal birth cohort study investigation of 1,037 children (48.4% female) born in Dunedin, New Zealand, between April 1, 1972, and March 31, 1973, and assessed repeatedly since then. Associations between posterior crossbite, overbite, and overjet at age 15, as well as both self-reported and clinically assessed TMJ clicking sounds at age 45, were studied. Data were analyzed using multivariate logistic regression, after controlling for sex, emotional style, self-reports of tooth clenching and sleep bruxism, and history of orthodontic treatment. Self-reported and examiner-reported TMJ clicking at age 45 affected 18.3% and 23.8% of the study sample, respectively, and were not associated with the presence of a posterior crossbite or abnormal overjet/overbite values during adolescence. Self-reported history of tooth clenching and emotional style were associated with self-reported TMJ clicking later in life. In addition, there is a suggestion that high overbite during adolescence is negatively associated with TMJ clicking later in life. A history of orthodontic treatment was not associated with TMJ clicking. Abnormal occlusal features, such as posterior crossbite and high and low overjet/overbite in adolescence, are not associated with higher prevalence of TMJ clicking later in life. Personality also appears to influence self-reports of TMJ clicking later in life.

Predicting Health-Related Quality of Life in Trauma-Exposed Male Veterans in Late Midlife: A 20 Year Longitudinal Study

Trauma-exposed adults with high levels of posttraumatic stress symptoms (PTSS) report poorer health-related quality of life (HRQOL), but less is known about the persistence of this relationship over time. Participants from the Vietnam Era Twin Study of Aging reported on PTSS, health, and sociodemographic characteristics at average age 38; 775 participants reported having been exposed to trauma. Later, at average ages 56 and 62, mental and physical HRQOL were assessed with the Short-Form 36. Premorbid risk for anxiety/neuroticism was evaluated with a polygenic risk score derived from a large genome-wide association study meta-analysis. In multivariate mixed models, having higher levels of PTSS, poorer self-rated health, lower income, and less education at age 38 were associated with worse physical and mental HRQOL two decades later. Chronic health problems at age 38 predicted midlife physical but not mental HRQOL. Although genetic risk for neuroticism was correlated with HRQOL and PTSS, it was no longer significant in multivariate models. Health-related quality of life (HRQOL) predicts morbidity and mortality independently of objective health measures; early interventions may help to mitigate the ongoing impact of trauma on quality of life.

Uncovering the complex genetics of human character

Human personality is 30-60% heritable according to twin and adoption studies. Hundreds of genetic variants are expected to influence its complex development, but few have been identified. We used a machine learning method for genome-wide association studies (GWAS) to uncover complex genotypic-phenotypic networks and environmental interactions. The Temperament and Character Inventory (TCI) measured the self-regulatory components of personality critical for health (i.e., the character traits of self-directedness, cooperativeness, and self-transcendence). In a discovery sample of 2149 healthy Finns, we identified sets of single-nucleotide polymorphisms (SNPs) that cluster within particular individuals (i.e., SNP sets) regardless of phenotype. Second, we identified five clusters of people with distinct profiles of character traits regardless of genotype. Third, we found 42 SNP sets that identified 727 gene loci and were significantly associated with one or more of the character profiles. Each character profile was related to different SNP sets with distinct molecular processes and neuronal functions. Environmental influences measured in childhood and adulthood had small but significant effects. We confirmed the replicability of 95% of the 42 SNP sets in healthy Korean and German samples, as well as their associations with character. The identified SNPs explained nearly all the heritability expected for character in each sample (50 to 58%). We conclude that self-regulatory personality traits are strongly influenced by organized interactions among more than 700 genes despite variable cultures and environments. These gene sets modulate specific molecular processes in brain for intentional goal-setting, self-reflection, empathy, and episodic learning and memory.

‘I always have fun at work’: How ‘remarkable workers’ employ agency and control in order to enjoy themselves

Organisations and associated management practices are generally considered responsible for promoting employees' enjoyment of work. Our study, on the other hand, seeks to examine the capacity of individual workers to regulate their own experience of fun. We interviewed eight ‘remarkable’ workers who claimed to always (or nearly always) have fun at work. We utilised a critical realist approach in the analysis that enabled the consideration of both structure and agency in the experience of workplace fun. A key research finding was that participants possessed a strong sense of control over their own happiness at work, demonstrated in four ways: (1) a priority placed on fun, (2) a sense of responsibility for fun, (3) a positive orientation to the world and (4) a sense of mastery and challenge in work tasks. Research findings may inspire both individual workers and organisations to adopt an agentic outlook in the workplace, implementing strategies that enhance employee control.

Absorption and spiritual experience: A review of evidence and potential mechanisms

Some people seem to have a 'talent' for spiritual experience: they readily sense the presence of supernatural beings, receive special messages from God, and report intense feelings of self-transcendence, awe and wonder. Here we review converging strands of evidence to argue that the trait of 'absorption' captures a general proclivity for having spiritual experiences. Participants scoring highly on the Tellegen Absorption Scale report vivid experiences of hearing God's voice during prayer, intense mystical experiences in response to psychedelics or placebo brain-stimulation, and strong feelings of presence and transcendence when confronted with natural beauty, virtual reality, or music. Several mechanisms may help to explain the relationship between absorption and spiritual experience. We suggest that absorption captures an experiential mindset that intensifies inner and outer sensory experience in ways that reflect both prior expectation and novel sensory engagement. It seems to enable that which must be imagined to feel more real.

The Relative Importance of Personality, Financial Satisfaction, and Autonomy for Different Subjective Well-Being Facets

Using a nationally representative sample (N = 507) from Singapore, this study examined whether personality, financial satisfaction, and autonomy were important to subjective well-being (SWB), and how the importance of these predictors varied across different SWB facets-life satisfaction, happiness, positive feelings, and negative feelings. The findings indicated that neuroticism, financial satisfaction, and autonomy, were important predictors of happiness. Personality was most important for affective well-being (i.e., positive and negative feelings), whereas financial satisfaction was most important for life satisfaction. Specifically, neuroticism accounted for substantial variance in positive and negative feelings, and was the strongest correlate among the Big Five traits. In contrast, financial satisfaction explained most of the variance in life satisfaction. This highlights that the importance of well-being predictors depended on the facet of well-being examined. The findings suggest that residents in an affluent nation like Singapore do not emphasize only postmaterialist values (e.g., autonomy) and disregard materialist concerns (e.g., financial satisfaction). Though certain SWB facets (positive and negative affect) are largely influenced by dispositional factors, other facets (life satisfaction and happiness) are closely related to factors (e.g., financial satisfaction, autonomy) that may be affected by social policies. Policymakers can thus target those aspects to enhance people's SWB.

What is the natural measurement unit of temperament: single traits or profiles?

There is fundamental doubt about whether the natural unit of measurement for temperament and personality corresponds to single traits or to multi-trait profiles that describe the functioning of a whole person. Biogenetic researchers of temperament usually assume they need to focus on individual traits that differ between individuals. Recent research indicates that a shift of emphasis to understand processes within the individual is crucial for identifying the natural building blocks of temperament. Evolution and development operate on adaptation of whole organisms or persons, not on individual traits or categories. Adaptive functioning generally depends on feedback among many variable processes in ways that are characteristic of complex adaptive systems, not machines with separate parts. Advanced methods of unsupervised machine learning can now be applied to genome-wide association studies and brain imaging in order to uncover the genotypic-phenotypic architecture of traits like temperament, which are strongly influenced by complex interactions, such as genetic epistasis, pleiotropy and gene-environment interactions. We have found that the heritability of temperament can be nearly fully explained by a large number of genetic variants that are unique for multi-trait profiles, not single traits. The implications of this finding for research design and precision medicine are discussed.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Intersubject similarity of personality is associated with intersubject similarity of brain connectivity patterns

Personality is a central high-level psychological concept that defines individual human beings and has been associated with a variety of real-world outcomes (e.g., mental health and academic performance). Using 2 h, high resolution, functional magnetic resonance imaging (fMRI) resting state data of 984 (primary dataset N = 801, hold-out dataset N = 183) participants from the Human Connectome Project (HCP), we investigated the relationship between personality (five-factor model, FFM) and intrinsic whole-brain functional connectome. We found a pattern of functional brain connectivity ("global personality network") related to personality traits. Consistent with the heritability of personality traits, the connectivity strength of this global personality network is also heritable (more similar between monozygotic twin pairs compared to the dizygotic twin pairs). Validated by both the repeated family-based 10-fold cross-validation and hold-out dataset, our intersubject network similarity analysis allowed us to identify participants' pairs with similar personality profiles. Across all the identified pairs of participants, we found a positive correlation between the network similarity and personality similarity, supporting our "similar brain, similar personality" hypothesis. Furthermore, the global personality network can be used to predict the individual subject's responses in the personality questionnaire on an item level. In sum, based on individual brain connectivity pattern, we could predict different facets of personality, and this prediction is not based on localized regions, but rather relies on the individual connectivity pattern in large-scale brain networks.

Comparison of personality between juveniles and adults in clonal gecko species

The developmental perspectives of animal personality enhance our understanding of how personality structure changes in relation to life stage. Clonal animals are ideal models for developmental studies because personality differences can be solely attributed to environmental factors. Here, I investigated the presence of personality within a species of clonal gecko, Lepidodactylus lugubris, at different developmental stages. For juveniles and adult geckos, I measured exploration (reaction to a novel situation) and boldness (risk-prone tendency) and evaluated repeatability and correlation of these behavioural traits. Each gecko exhibited different exploration and boldness with significant repeatability through time but no correlation between these behavioural traits. Small juveniles were composed of only bold and low explorative individuals but large juveniles and adults were composed of various personality type individuals. These results demonstrate that subject geckos have a similar personality structure across life stages and that exploration and boldness are independent personality without forming behavioural syndrome structure. Biased composition of personality type between life stages suggests that appearance of different personality type individuals during an early ontogenetic stage generates personality variation within the clonal population. This study provides developmental insight about personality structure and its composition in clonal animals living in the wild.

Exploring constructs of well-being, happiness and quality of life

Background

Existing definitions of happiness, subjective well-being, and quality of life suggest conceptual overlap between these constructs. This study explored the relationship between these well-being constructs by applying widely used measures with satisfactory psychometric properties.

Materials and Methods

University students (n = 180) completed widely used well-being measures including the Oxford Happiness Questionnaire (OHQ), the World Health Organization Quality of Life Questionnaire, the Satisfaction with Life Scale, and the Positive and Negative Affect Scale. We analyzed the data using correlation, regression, and exploratory factor analysis.

Results

All included well-being measures demonstrated high loadings on the global well-being construct that explains about 80% of the variance in the OHQ, the psychological domain of Quality of Life and subjective well-being. The results show high positive correlations between happiness, psychological and health domains of quality of life, life satisfaction, and positive affect. Social and environmental domains of quality of life were poor predictors of happiness and subjective well-being after controlling for psychological quality of life.

Conclusion

Together, these data provide support for a global well-being dimension and interchangeable use of terms happiness, subjective well-being, and psychological quality of life with the current sample and measures. Further investigation with larger heterogeneous samples and other well-being measures is warranted.

A Five-Factor Theory Perspective on Causal Analysis

Five-Factor Theory (FFT) provides a broad but largely blank template for causal personality research. Within FFT, there are three major categories of questions: (1) How do biological structures and functions lead to trait levels? (2) how do traits and the environment give rise to acquired psychological institutions? and (3) how do personality characteristics interact with specific situations to determine behaviors and reactions? Both practical and ethical issues complicate the search for the causes of trait change. Causal explanations of the development of characteristic adaptations are likely to be incomplete, because there are many different ways in which the same adaptation may be acquired. Studies of the determinants of behavior are usually left to social, educational, or clinical psychologists-although personality psychologists may make distinctive contributions by emphasizing the role of the individual in selecting and creating situations. A causal understanding of the functioning of the personality system is possible through the integration of many lines of evidence, but it is likely to take a very long time. In the meanwhile, personality psychologists may fruitfully pursue the identification of practical causes by which individuals with a given set of traits can optimize their adaptation. If we require truth in any strict sense, we must confine ourselves to one entire state of the world. This will be the cause, and the next entire state will be the effect. There is much truth in this conclusion, but it remains indefensible.F. H. Bradley, 1893/1966, p. 48.