Common genetic and environmental bases of the mental disorders and personality traits: Special focus on the hierarchical model of psychopathology and NEO-PI-R facets.

OBJECTIVE: This study examined whether phenotypic correlations between psychopathological dimensions and personality traits of different hierarchical levels originate from common genetic and environmental sources of variance. METHOD: Participants were 386 monozygotic and 204 dizygotic twins. The Psychiatric Diagnostic Screening Questionnaire (PDSQ) was applied along with the Revised NEO Personality Inventory (NEO-PI-R). The results of the CFA confirmed the hypothesis of the internalizing and externalizing dimensions underlying PDSQ scales. RESULTS: The results indicated a significantly greater role of genetic compared to environmental factors in the relationship between internalizing psychopathology and personality traits. Facets of neuroticism showed positive genetic links with internalizing disorders, while negative genetic links were shown for all facets of extraversion except excitement-seeking, competence, self-discipline, achievement striving, actions, and trust. Lower-order personality traits were shown to be associated with internalizing disorders more intensively than the broader domains to which they belong, both at the phenotypic and genetic levels. CONCLUSIONS: High neuroticism, together with several facets from the domain of extraversion and conscientiousness seems to represent an increased genetic susceptibility to the disorders from the internalizing spectrum. Results also suggest that specific environmental factors which are not shared with personality traits contribute to the internalizing symptoms.

Latent, genetic, and molecular genetic structure of the Wisconsin Card Sorting Test.

OBJECTIVE: The main goal of this study was to explore the latent structure and genetic basis of cognitive processes involved in the Wisconsin Card Sorting Task (WCST) within phenotypic, behavioral genetic, and molecular genetic research paradigms. METHOD: The sample used in phenotypic and behavioral genetic analyses comprised 468 twins (154 monozygotic and 80 dizygotic twin pairs), while molecular genetic analyses were performed on 404 twins from the same sample. The zygosity of most twin pairs (96.8%) was determined via deoxyribonucleic acid (DNA) analysis of buccal swabs. Trained researchers administered the Wisconsin Card Sorting Test (WCST; Heaton et al., 1993) to the entire sample. RESULTS: A phenotypic factor analysis of WCST variables suggested a single-factor solution. Overall heritability ranged from 0.19 to 0.23 across different measures of the WCST. The presence of a single general genetic factor, which could be identified from different measures of the WCST, indicated the unity of various WCST indicators and the existence of a common basic ability. Performance on the WCST did not reveal significant differences between the three genotypes on catechol-O-methyltransferase (COMT) and dopamine receptor D2 (DRD2). Carriers of the brain-derived neurotrophic factor (BDNF) Met + genotype exhibited better performance in cognitive functions in comparison to the BDNF Met- genotype. CONCLUSIONS: This study highlighted similarities in the phenotypic and genetic structures of the WCST, suggesting one general factor underlying different cognitive functions. The BDNF Met + genotype showed significant main effects on different WCST measures. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Quantitative behavioral genetic and molecular genetic foundations of the approach and avoidance strategies.

Two studies examined genetic and environmental influences on traits proposed by the revised Reinforcement Sensitivity Theory (rRST) of personality. Both quantitative and molecular behavioral genetic methods were applied considering the effects of COMT, DRD2, HTR1A and TPH2 single nucleotide polymorphisms (SNPs). Study one included 274 monozygotic and 154 dizygotic twins for the quantitative behavioral study; and in study two there were 431 twins for the molecular genetic study. The Reinforcement Sensitivity Questionnaire was used to assess basic personality traits defined by the rRST. Univariate biometric modeling suggested that genetic influences accounted for 34-44% of variance of Behavioral Approach System (BAS), Behavioral Inhibition System (BIS) and Fight-Fligh-Freeze System. Molecular genetic analyses proposed the significant main effect of COMT SNP on the BAS and TPH2 SNP on the BIS, and pointed out epistatic effects of COMT x DRD2 on BAS and HTR1A x TPH2 on Fight. Results demonstrated substantial heritability for all rRST constructs, as well as for differences in the molecular genetic basis of both approach-related and avoidance-related dimensions.

Differences in MB-COMT DNA methylation in monozygotic twins on phenotypic indicators of impulsivity.

Epigenetic modifications of the membrane bound catechol-O-methyltransferase (MB-COMT) gene may affect the enzymatic degradation of dopamine, and consequently, human behavior. This study investigated the association between membrane bound catechol-O-methyltransferase DNA methylation (DNAm) differences in 92 monozygotic (MZ) twins with phenotypic manifestations of cognitive, behavioral, and personality indicators associated with reward-related behaviors and lack of control. We used pyrosequencing to determine DNAm of the regulatory region of membrane bound catechol-O-methyltransferase in saliva DNA. Results of intrapair differences in the percentage of membrane bound catechol-O-methyltransferase DNAm at each of five CpG sites show that there are associations between phenotypic indicators of lack of control and membrane bound catechol-O-methyltransferase DNAm differences on CpG1, CpG2 and CpG4, suggesting the common epigenetic patterns for personality traits, cognitive functions, and risk behaviors.

A person-centered approach in studying coronavirus pandemic response: The role of HEXACO-PI-R and PANAS dimensions.

The main aim of this study was to explore reactions to the COVID-19 pandemic and their relationship with personality traits using a person-centered approach. Sample of 471 Serbian citizens was collected during the first 7 weeks of the pandemic. Cluster analysis revealed three clusters based on reactions to the pandemic: Adapted, Antagonized, and Passive. Adaptive type is characterized by stable emotional reactions and adherence to behavioral guidelines. Antagonized cluster is characterized by lowered adherence to behavioral guidelines, while Passive cluster is characterized by increased fear and boredom. Clusters differed significantly on HEXACO and PANAS traits. Similarity of obtained clusters with prototypes that commonly emerge using personality traits for classification, stresses the importance of basic individual differences in pandemic-induced behavior.

Daily Monitoring of Emotional Responses to the Coronavirus Pandemic in Serbia: A Citizen Science Approach.

The COVID-19 pandemic, a health emergency with international consequences, has brought serious impact on all aspects of society and affects not only health and economy, but psychological functioning and mental health as well. This research was conducted in order to examine and further our understanding of emotional reactions to the ongoing pandemic. Change in emotional reactions during the pandemic and relations with specific pandemic related behaviors and personality traits from the revised Reinforcement sensitivity theory were explored. The research was conducted in Serbia for 35 days while the country was in a state of emergency, as a citizen science project. Out of the 1526 participants that joined the study, 444 (67% female) had measures for all five weeks. Longitudinal changes in four emotional states during the pandemic were examined: worry, fear, boredom, and anger/annoyance. Results indicate a decrease in all four emotional states over time. The biggest decrease was present in case of worry, followed by fear and boredom. Regression analysis showed that personality dimensions, as well as behavioral responses in this situation significantly predicted emotional reactions. Findings revealed the Behavioral activation system was significantly related to worry, fear and boredom, Fight with boredom and anger, and the Behavioral inhibition system with anger. Adherence to protection measures, as well as increased exposure to the media, had significant positive relations with worry and fear. These results indicate that both stable characteristics and specific pandemic-related behaviors are significantly related to emotional response during the pandemic.

Twin study of laboratory-induced aggression.

The aim of this study was to explore genetic and environmental contributions to laboratory-induced aggressive behavior. On a sample of 478 adult twins (316 monozygotic), the Competitive Reaction Time Task was used for aggression induction. The results showed that the initial, basic level of aggression could be explained by both shared (45%) and nonshared environmental factors (55%), while only nonshared environmental factors (100%) had a significant influence on changes in aggression as provocation increased. Genetic factors had no influence on laboratory-induced aggression. The results highlight the importance of environmental factors in shaping situation-specific aggressive responses to provocation.

The HEXACO-100 Across 16 Languages: A Large-Scale Test of Measurement Invariance.

The HEXACO Personality Inventory-Revised (HEXACO-PI-R) has become one of the most heavily applied measurement tools for the assessment of basic personality traits. Correspondingly, the inventory has been translated to many languages for use in cross-cultural research. However, formal tests examining whether the different language versions of the HEXACO-PI-R provide equivalent measures of the 6 personality dimensions are missing. We provide a large-scale test of measurement invariance of the 100-item version of the HEXACO-PI-R across 16 languages spoken in European and Asian countries (N = 30,484). Multigroup exploratory structural equation modeling and confirmatory factor analyses revealed consistent support for configural and metric invariance, thus implying that the factor structure of the HEXACO dimensions as well as the meaning of the latent HEXACO factors is comparable across languages. However, analyses did not show overall support for scalar invariance; that is, equivalence of facet intercepts. A complementary alignment analysis supported this pattern, but also revealed substantial heterogeneity in the level of (non)invariance across facets and factors. Overall, results imply that the HEXACO-PI-R provides largely comparable measurement of the HEXACO dimensions, although the lack of scalar invariance highlights the necessity for future research clarifying the interpretation of mean-level trait differences across countries.

Serbian Twin Registry.

The first twin study in Serbia began in 2011 as a part of the research project, 'Psychological Foundations of Mental Health: Hereditary and Environmental Factors'. At the same time, the research team from the Faculty of Philosophy and Faculty of Medicine in Novi Sad established the first Serbian twin registry. The registry is intended primarily for the purpose of the research in behavioral genetics, as well as potential future studies in human genetics. It includes information on 1658 volunteers, including twin-pairs, their parent and siblings. The behavioral genetic study of adult twins has been focused on the hereditary and environmental sources of variance of different psychological characteristics, such as personality traits, cognitive abilities, executive functions and aggression, as well as some anthropometric measures and aspects of mental and physical health. Certain molecular genetic analyses have also been performed. The research team is currently starting the longitudinal twin study of children, which will be focused on different indicators of emotional, cognitive and physical development.

The HEXACO Personality Inventory: Validation and Psychometric Properties in the Serbian Language.

The aim of this research is to validate the HEXACO model of personality in the Serbian language through psychometric validation of the 100-item version of the HEXACO-PI-R. The research was conducted on 2 independent samples, the first comprising 1,217 participants from a community sample (55.5% females; average age = 31.77 years), and the second 345 undergraduate students (65% females; average age = 21 years). Besides the HEXACO-PI-R, 2 questionnaires were applied for the purposes of convergent validation: the Big Five Plus Two (BF+2), measuring 7 lexical personality dimensions (applied in Sample 1), and the Big Five Inventory (BFI; applied in Sample 2). Factor structure of the HEXACO-PI-R is in line with model assumptions. Convergent validity is good, whereby Extraversion, Openness to Experience, and Conscientiousness are highly correlated to their BFI and BF+2 counterparts. Honesty-Humility is most closely related to Negative Valence (BF+2), Emotionality to BFI Neuroticism, and Agreeableness to BF+2 Aggressiveness and BFI Agreeableness. The results point to the satisfactory validity of the HEXACO model and its measure in the Serbian language.

A Short Measure of the Revised Reinforcement Sensitivity Theory - RSQ17.

The need for a research and practical tool, such as a short, reliable, and valid personality assessment test, suggests researchers to create shortened versions of original instruments. Reinforcement sensitivity questionnaire (RSQ) was created in line with some basic premises of revised Reinforcement sensitivity theory, which proposes three motivational and emotional systems: Behavioral inhibition system (BIS), responsible for scanning environment for potential threats, Behavioral activation system (BAS), responsible for aproaching behavior, and the Fight/Flight/Freeze system (FFFS), responsible for behavior in the present threat. RSQ comprises five scales: BIS, BAS, Fight, Flight, and Freeze. The aim of this study was to develop a short version of RSQ, which would be beneficial to both research and practical purposes. Item response theory analyses were used for item selection. The study comprised two samples of participants, whereby Sample 1 (N = 837, 34.6% male, aged 18 - 82, M = 31.63, SD = 13.54) served as the derivation sample, while Sample 2 (818 participants, 43.6% male, 18-75 years, M = 29.65, SD = 12.52) served as validation sample. Factorial validity of the short RSQ was examined on both Sample 1 and Sample 2. Convergent and divergent validity of the short RSQ was examined using RST-PQ, Jackson-5, BIS/BAS scales, and Big Five Inventory. The results point to satisfactory internal consistency, factorial validity, and construct validity of the short RSQ, suggesting that it is an adequate measure for research settings or other contexts which require the use of short personality questionnaires.

School bullying in adolescence and personality traits: a person-centered approach.

This study examined the differences in personality traits between the clusters reflecting the roles in violent interactions among high school students. The sample included 397 students (51.1% male) of Serbian nationality from the first to the fourth grades of different high schools. Based on scores of five dimensions related to peer violence (Physical Aggression, Psychological Aggression, Victimization, Adapted Behavior, and Risky Behavior), three clusters were extracted: Adapted Adolescents, Victims, and Bullies. These three clusters were compared with respect to lexical Big Seven personality traits, and the results indicate that the clusters differ significantly on Aggressiveness, Neuroticism, and Negative Valence. The Adapted Adolescents have the lowest scores on all three dimensions, while the Victims score highest on Neuroticism, and the Bullies on Aggressiveness. The potential importance of certain Extraversion facets for the roles in violent interaction was discussed.