Sex differences in the Big Five model personality traits: A behavior genetics exploration

Though Forced, Still Valid: Examining the Psychometric Performance of Forced-Choice Measurement of Personality in Children and Adolescents

Unveiling the roles personality plays during childhood and adolescence necessitates its accurate measurement, commonly using traditional Likert-type (LK) scales. However, this format is susceptible to various response biases, which can be particularly prevalent in children and adolescents, thus likely undermining measurement accuracy. Forced-choice (FC) scales appear to be a promising alternative because they are largely free from these biases by design. However, some argue that the FC format may not perform satisfactorily in children and adolescents due to its complexity. Little empirical evidence exists regarding the suitability of the FC format for children and adolescents. As such, the current study examined the psychometric performance of an FC measure of the Big Five personality factors in three children and adolescent samples: 5th to 6th graders (N = 428), 7th to 8th graders (N = 449), and 10th to 11th graders (N = 555). Across the three age groups, the FC scale demonstrated a better fit to the Big Five model and better discriminant validity in comparison to the LK counterpart. Personality scores from the FC scale also converged well with those from the LK scale and demonstrated high reliability as well as sizable criterion-related validity. Furthermore, the FC scale had more invariant statements than its LK counterpart across age groups. Overall, we found good evidence showing that FC measurement of personality is suitable for children and adolescents.

Gender differences in the relationship between neuroticism and odor memory

Given the indications on the relationship between neuroticism and various olfactory functions as well as the emotionality of odor memory, it is surprising that no research so far has investigated whether neuroticism corresponds with odor memory performance. Thus, the purpose of our study was to address this question in the context of gender differences. Participants (73 men) completed the 60-items NEO Five Factor Inventory and participated in 32-items "Test for odor memory". In the separate analyses conducted for men and women, we demonstrated that women outperformed men regarding the number of correct odor recognitions in the odor memory test and had higher neuroticism level than men. Spearman correlation showed further that neuroticism was positively associated with D-prime (R = 0.3, p = .021) and the number of correct odor recognitions in women (R = 0.32, p = .014). This effect was, respectively, moderately (B10 = 5.2) and strongly confirmed using the Bayesian approach (B10 = 8). However, Bonferroni post-hoc correction for multiple comparisons further revealed that in case of neuroticism and the number of hits, as well as D-prime, alpha level was below significance, indicated by p = .006. The correlation between neuroticism level and odor memory performance was significantly higher in women compared to men (Z = 1.8, p = .038), while in case of neuroticism and D-prime, it was on a trend level (Z = 1.5, p = .074). Overall, the present results indicate that neuroticism might be linked to conscious odors' remembering for women, which can be explained by the warning role of odor memory and its connection to limbic structures, as well as by the higher level of neuroticism and odor memory performance in women compared to men.

Basic or Adaptation: The Assessment and Heritability of a Brief Measure of Agency

The interpersonal circumplex describes two major axes of personality that guide much of social behavior. Agency, one half of the interpersonal circumplex, refers to relatively stable behavioral patterns that center on self-focused dominance and assertiveness. Past empirical work on agency tends to treat the dimension as a characteristic adaptation, rather than a basic component of personality, in part due to the relatively large gender difference in agency with masculine individuals tending to behave more agentic. However, the psychometric overlap between agency and the most closely linked big five dimension, extraversion, is not well-established, and no behavior genetic work has documented evidence concerning the role of genetic and environmental influences. It is unclear whether agency is more similar to a personality trait, with no evidence of shared environmental influence and moderate heritability, or a characteristic adaptation, with some evidence for shared environmental influence and possibly lower heritability. We used the Midlife Development in the United States study to examine agency, big five, and generativity with replication and robustness check (Nnon-twins = 5,194; Ntwins = 1,914; NMilwaukee = 592). Results indicated that agency was higher in men (d = -.24), moderately heritable (44.4%), strongly correlated with extraversion (r = .51), moderately correlated with generativity (r = .36), and that approximately 40% of the variance in agency was shared with the big five. Agency also changed strongly with extraversion and openness, but less so generativity. Altogether, these results indicate that agency functions similar to other basic personality dimensions but is not clearly a dispositional trait.

Effects of Genetic Relatedness of Kin Pairs on Univariate ACE Model Performance

The current study explored the impact of genetic relatedness differences (ΔH) and sample size on the performance of nonclassical ACE models, with a focus on same-sex and opposite-sex twin groups. The ACE model is a statistical model that posits that additive genetic factors (A), common environmental factors (C), and specific (or nonshared) environmental factors plus measurement error (E) account for individual differences in a phenotype. By extending Visscher's (2004) least squares paradigm and conducting simulations, we illustrated how genetic relatedness of same-sex twins (HSS) influences the statistical power of additive genetic estimates (A), AIC-based model performance, and the frequency of negative estimates. We found that larger HSS and increased sample sizes were positively associated with increased power to detect additive genetic components and improved model performance, and reduction of negative estimates. We also found that the common solution of fixing the common environment correlation for sex-limited effects to .95 caused slightly worse model performance under most circumstances. Further, negative estimates were shown to be possible and were not always indicative of a failed model, but rather, they sometimes pointed to low power or model misspecification. Researchers using kin pairs with ΔH less than .5 should carefully consider performance implications and conduct comprehensive power analyses. Our findings provide valuable insights and practical guidelines for those working with nontwin kin pairs or situations where zygosity is unavailable, as well as areas for future research.

Sex-Specific Genetic and Transcriptomic Liability to Neuroticism

BACKGROUND

The presentation, etiology, and relative risk of psychiatric disorders are strongly influenced by biological sex. Neuroticism is a transdiagnostic feature of psychiatric disorders displaying prominent sex differences. We performed genome-wide association studies of neuroticism separately in males and females to identify sex-specific genetic and transcriptomic profiles.

METHODS

Neuroticism scores were derived from the Eysenck Personality Inventory Neuroticism scale. Genome-wide association studies were performed in 145,669 females and 129,229 males from the UK Biobank considering autosomal and X chromosomal variation. Two-sided z tests were used to test for sex-specific effects of discovered loci, genetic correlates (n = 673 traits), tissue and gene transcriptomic profiles, and polygenic associations across health outcomes in the Vanderbilt University Biobank (39,692 females and 31,268 males).

RESULTS

The single nucleotide polymorphism heritability of neuroticism was not statistically different between males (h2 = 10.6%) and females (h2 = 11.85%). Four female-specific (rs10736549-CNTN5, rs6507056-ASXL3, rs2087182-MMS22L, and rs72995548-HSPB2) and 2 male-specific (rs10507274-MED13L and rs7984597) neuroticism risk loci reached genome-wide significance. Male- and female-specific neuroticism polygenic scores were most significantly associated with mood disorders (males: odds ratio = 1.11, p = 1.40 × 10-9; females: odds ratio = 1.14, p = 6.05 × 10-22). They also associated with sex-specific laboratory measurements related to erythrocyte count, distribution, and hemoglobin concentration. Gene expression variation in the pituitary was enriched for neuroticism loci in males (male: b = 0.026, p = .002), and genetically regulated transcriptomic changes highlighted the effect of SHISHA9, TEX26, and NCOA6.

CONCLUSIONS

Through a comprehensive assessment of genetic risk for neuroticism and the associated biological processes, this study identified several molecular pathways that can partially explain the known sex differences in neurotic symptoms and their psychiatric comorbidities.

Narrative Review of Sex Differences in Muscle Strength, Endurance, Activation, Size, Fiber Type, and Strength Training Participation Rates, Preferences, Motivations, Injuries, and Neuromuscular Adaptations

ABSTRACT

Nuzzo, JL. Narrative review of sex differences in muscle strength, endurance, activation, size, fiber type, and strength training participation rates, preferences, motivations, injuries, and neuromuscular adaptations. J Strength Cond Res 37(2): 494-536, 2023-Biological sex and its relation with exercise participation and sports performance continue to be discussed. Here, the purpose was to inform such discussions by summarizing the literature on sex differences in numerous strength training-related variables and outcomes-muscle strength and endurance, muscle mass and size, muscle fiber type, muscle twitch forces, and voluntary activation; strength training participation rates, motivations, preferences, and practices; and injuries and changes in muscle size and strength with strength training. Male subjects become notably stronger than female subjects around age 15 years. In adults, sex differences in strength are more pronounced in upper-body than lower-body muscles and in concentric than eccentric contractions. Greater male than female strength is not because of higher voluntary activation but to greater muscle mass and type II fiber areas. Men participate in strength training more frequently than women. Men are motivated more by challenge, competition, social recognition, and a desire to increase muscle size and strength. Men also have greater preference for competitive, high-intensity, and upper-body exercise. Women are motivated more by improved attractiveness, muscle "toning," and body mass management. Women have greater preference for supervised and lower-body exercise. Intrasexual competition, mate selection, and the drive for muscularity are likely fundamental causes of exercise behaviors in men and women. Men and women increase muscle size and strength after weeks of strength training, but women experience greater relative strength improvements depending on age and muscle group. Men exhibit higher strength training injury rates. No sex difference exists in strength loss and muscle soreness after muscle-damaging exercise.

A study on impostor phenomenon, personality, and self-esteem of medical undergraduates and interns

Introduction

Impostor phenomenon (IP) is a psychological experience where an individual considers their achievements to be fraudulent. IP in medical professionals is of paramount importance since it affects their self-confidence and communication skills. It has been associated with burnouts, low self-esteem, and neuroticism.

Aim

This research aimed to study the prevalence of IP, personality traits, and self-esteem and to look at gender differences in medical undergraduate students and interns of an urban medical college along with the correlation of IP with personality traits and self-esteem in them.

Methodology

An online survey via Google Groups was conducted among MBBS students and interns of a medical college after informed consent and ethics approval were received. Four hundred sixteen participants completed the survey questionnaire which included demographic variables along with the the Clance Impostor Phenomenon Scale, the Big Five Inventory, and the Rosenberg Self-Esteem Scale.

Results

IP was found in 236 (56.7%) students and interns. Personality domain mean scores were extraversion (26.4 ± 5.12), agreeableness (33.5 ± 5.4), conscientiousness (29.9 ± 5.7), neuroticism (21.6 ± 5.7), and openness (35.1 ± 4.9). The self-esteem mean score was 18.37 ± 6.14; only 16.11% had high self-esteem. Interns and first-year MBBS students scored higher on IP and low on self-esteem among all groups. Significant gender differences were seen in females on agreeableness, conscientiousness, and neuroticism as compared to the males. IP negatively correlated with self-esteem, extraversion, agreeableness, and conscientiousness and positively with neuroticism.

Conclusion

This study throws some light on the IP experiences of medical undergraduates which have not been extensively researched in India.

The value of tourism public opinion management in social governance: A study on the impact of electronic word-of-mouth perception on people's livelihood well-being

In the process of tourism market upgrading and tourism iteration, tourism companies will face a more complex public opinion environment. Designing a socialized public opinion management method for tourism with social governance to improve people's livelihood and well-being has become the primary concern of the tourism industry. Therefore, the existing literature has extensively focused on the role and influence of public opinion word of mouth from the perspective of tourist or consumer behavior. However, moderating role of individual tourist characteristics and environmental elements has not yet been deeply explored. Therefore, integrating with the background of the social media, this study examines how electronic word-of-mouth (eWOM) is related to the well-being of people's livelihood, and explores the interaction between individual characteristics and eWOM perception in Study 1. Furthermore, in Study 2, we provided novel boundary conditions, namely environmental elements (i.e., physical, social and historical environment). We used mixed methods (i.e., quantitative and experimental designs) to reveal that tourists' perceptions of eWOM have a significant positive effect on tourists' well-being experience. The results show that tourists' eWOM perception has a significant positive impact on their well-being experience. In addition, individual characteristics and environmental elements showed significant moderating effects between eWOM and well-being of people's livelihood. This study discusses the theoretical and practical implications, exploring the value of tourism public opinion management in social governance centered on tourists' eWOM perception, which helps tourism companies to effectively prevent and resolve risks affecting social harmony and stability in the field of cultural tourism and create a safe and stable cultural tourism market environment.

Unraveling the Relation Between Personality and Well-Being in a Genetically Informative Design

In the current study, common and unique genetic and environmental influences on personality and a broad range of well-being measures were investigated. Data on the Big Five, life satisfaction, quality of life, self-rated health, loneliness, and depression from 14,253 twins and their siblings (age M: 31.82, SD: 14.41, range 16–97) from the Netherlands Twin Register were used in multivariate extended twin models. The best-fitting theoretical model indicated that genetic variance in personality and well-being traits can be decomposed into effects due to one general, common factor ( Mdn: 60%, range 15%–89%), due to personality-specific ( Mdn: 2%, range 0%–78%) and well-being-specific ( Mdn: 12%, range 4%–35%) factors, and trait-specific effects ( Mdn: 18%, range 0%–65%). Significant amounts of non-additive genetic influences on the traits’ (co)variances were found, while no evidence was found for quantitative or qualitative sex differences. Taken together, our study paints a fine-grained, complex picture of common and unique genetic and environmental effects on personality and well-being. Implications for the interpretation of shared variance, inflated phenotypic correlations between traits and future gene finding studies are discussed.

The Big Five and Big Two personality factors in Mongolia

Etic psychometric tools work less well in non-Western than in Western cultures, whereas data collected online in the former societies tend to be of superior quality to those from face-to-face interviews. This represents a challenge to the study of the universality of models of personality and other constructs. If one wishes to uncover the true structure of personality in a non-Western nation, should one study only highly educated, cognitively sophisticated Internet users, and exclude the rest? We used a different approach. We adapted a short Big Five tool, previously tested successfully in 19 countries on all continents, to Mongolian culture. EFA and CFA analyses across a nationally representative sample of 1,500 adult Mongolians recovered the Big Five satisfactorily. A Big Two (plasticity and stability) model was also recovered reasonably well. Correlations between personality traits and age, as well as gender differences, were not different from those reported for Western samples. Respondents with higher education, or higher-than-average socioeconomic status, or urban dwellers, or Internet users, did not yield a clearer Big Five than the whole sample. Our method (tool adaptation to a local cultural context) may be preferable to exclusion of specific demographic groups in Big Five studies of non-Western populations.

Pandemic prevention and personality psychology: Gender differences in preventive health behaviors during COVID-19 and the roles of agreeableness and conscientiousness

One of the greatest public health crises in recent times, the COVID-19 pandemic, has come with a myriad of challenges in terms of health communication and public cooperation to prevent the spread of the disease. Understanding which are the key determinants that make certain individuals more cooperative is key in effectively tackling pandemics and similar future challenges. In the present study (N = 800), we investigated whether gender differences in compliance with preventive health behaviors (PHB) at the onset of the COVID-19 pandemic could be established, and, if so, whether the personality traits of agreeableness and conscientiousness could help explain this presumed relationship. Consistent with our theorizing, we found women to score higher than men on agreeableness and conscientiousness, and to be more willing to comply with a set of PHB. Importantly, both personality traits were found to mediate the gender-compliance link. This means that women's greater compliance levels with PHB could, at least in part, be attributed to their higher agreeableness and conscientiousness scores. A greater understanding of the determinants of PHB in terms of gender and associated personality traits may help identify options for developing more effective communication campaigns, both in terms of communication channel selection and message content.

Structural brain differences do not mediate the relations between sex and personality or psychopathology

INTRODUCTION

Males and females tend to exhibit small but reliable differences in personality traits and indices of psychopathology that are relatively stable over time and across cultures. Previous work suggests that sex differences in brain structure account for differences in domains of cognition.

METHODS

We used data from the Human Connectome Project (N = 1098) to test whether sex differences in brain morphometry account for observed differences in the personality traits neuroticism and agreeableness, as well as symptoms of internalizing and externalizing psychopathology. We operationalized brain morphometry in three ways: omnibus measures (e.g., total gray matter volume), Glasser regions defined through a multi-modal parcellation approach, and Desikan regions defined by structural features of the brain.

RESULTS

Most expected sex differences in personality, psychopathology, and brain morphometry were observed, but the statistical mediation analyses were null: sex differences in brain morphometry did not account for sex differences in personality or psychopathology.

CONCLUSIONS

Men and women tend to exhibit meaningful differences in personality and psychopathology, as well as in omnibus morphometry and regional morphometric differences as defined by the Glasser and Desikan atlases, but these morphometric differences appear unrelated to the psychological differences.

Alternative model of personality disorders traits predict residential addictions treatment completion

BACKGROUND

Among people receiving residential treatment for a substance use disorder (SUD), premature treatment termination predicts poor post-treatment outcomes. We examined the utility of the alternative model for personality disorders (AMPD) for predicting premature residential SUD treatment termination, including interactions with age and gender.

METHODS

Participants (N = 374) were receiving residential treatment for SUD and enrolled in a clinical trial with two conditions: Skills for Improving Distress Intolerance (SIDI) and Supportive Counseling (NCT01741415). Participants were assessed at intake on AMPD traits using the Personality Inventory for DSM-5 (PID-5) and tracked longitudinally. After establishing gender and age measurement invariance, we used competing risk models to predict treatment completion versus premature termination using interactions of PID-5 scores with age and gender.

FINDINGS

Disinhibition and Negative Emotionality domains and facets predicted premature treatment termination, particularly among younger, male participants. There were positive effects of SIDI on treatment completion for participants with high levels of domain and facet Negative Emotionality. A small proportion (≈ 12 %) of the PID-5 items showed differential item functioning by age or gender; however, the aggregate impact on test-level total scores was negligible.

CONCLUSIONS

Participants (particularly young men) displaying poor self-control and emotional regulation are at risk for premature termination. These findings, together with minimal aggregate differential item functioning at the scale level, suggest that the PID-5 is a practically useful, construct-valid, non-proprietary measure, aspects of which can be used for screening in residential SUD treatment. Furthermore, among those with high negative emotionality, SIDI may be effective in preventing premature treatment termination.

Threat appraisal partially mediates the relation between neuroticism and bulimic symptoms

Several studies support an association between neuroticism and bulimic symptoms; however, few studies have focused on how neuroticism exerts its influence. The purpose of this study was to extend the literature by investigating threat appraisal as a potential mediator of the relation between neuroticism and bulimic symptoms. One hundred and twenty women completed self-report measures of trait neuroticism, threat appraisal, and bulimic symptoms. Approximately half of the sample reported moderate or high levels of bulimic symptoms. Bootstrapping analyses revealed that neuroticism and threat appraisal were both positive predictors of bulimic symptoms. Further, threat appraisal partially mediated the association between neuroticism and bulimic symptoms. The findings suggest that women high in neuroticism may be vulnerable to experiencing bulimic symptoms, particularly during periods of heightened stress. These women may perceive bulimic behavior to be more effective in alleviating negative stressful emotions compared to more adaptive coping strategies. Based on the findings, women diagnosed with bulimia nervosa with high levels of neuroticism may benefit from interventions that specifically target threat appraisals to facilitate their ability to effectively adapt to stress.

Examining Gender Differences, Personality Traits, Academic Performance, and Motivation in Ukrainian and Polish Students of Physical Education: A Cross-Cultural Study

Background: This study examined the relationship of academic performance with the Big Five traits of personality, academic motivation, and gender in a cross-cultural context. Methods: Participants in the study were 424 university students of physical education (PE) departments from Poland (53%) and Ukraine (47%). Undergraduates completed a brief version of the International Personality Item Pool (Mini-IPIP) to assess the Five-Factor model of personality, the Academic Motivations Scale (AMS), and grade point average (GPA). Results: Polish PE students scored higher in emotional stability and extroversion and had a higher GPA than Ukrainian PE undergraduates. Gender differences were found in both personality traits and academic motivation scales. Intrinsic motivation may predict academic performance. Conscientiousness and intellect emerged as mediators of the relationship between intrinsic motivation and academic performance and gender was found as a moderator in the relationship between conscientiousness and academic success. Conclusions: Women are more motivated regarding academic achievements than men. In addition to intrinsic motivation, the most important factors for academic grades are some personality traits, gender, and cultural differences. Openness and conscientiousness in men are mediators between intrinsic motivation and academic performance. The results of this study may be useful for PE academic teachers to improve the motivation of their students.

Relationships between big-five personality factors and Alzheimer's disease pathology in autosomal dominant Alzheimer's disease

INTRODUCTION

Changes in personality characteristics are associated with the onset of symptoms in Alzheimer's disease (AD) and may even precede clinical diagnosis. However, personality changes caused by disease progression can be difficult to separate from changes that occur with normal aging. The Dominantly Inherited Alzheimer Network (DIAN) provides a unique cohort in which to relate measures of personality traits to in vivo markers of disease in a much younger sample than in typical late onset AD.

METHODS

Personality traits measured with the International Personality Item Pool at baseline from DIAN participants were analyzed as a function of estimated years to onset of clinical symptoms and well-established AD biomarkers.

RESULTS

Both neuroticism and conscientiousness were correlated with years to symptom onset and markers of tau pathology in the cerebrospinal fluid. Self-reported conscientiousness and both neuroticism and conscientiousness ratings from a collateral source were correlated with longitudinal rates of cognitive decline such that participants who were rated as higher on neuroticism and lower on conscientiousness exhibited accelerated rates of cognitive decline.

DISCUSSION

Personality traits are correlated with the accumulation of AD pathology and time to symptom onset, suggesting that AD progression can influence an individual's personality characteristics. Together these findings suggest that measuring neuroticism and conscientiousness may hold utility in tracking disease progression in AD.

Personality functioning in adults with refractory epilepsy and community adults: Implications for health-related quality of life

INTRODUCTION

Prior research has shown that people with epilepsy are at risk for a poorer health-related quality of life (HRQOL). However, patients differ greatly in how well they adjust to their epilepsy. To better understand these differences, the present study examined the role of personality. More specifically, we examined mean-level differences in Big Five personality traits between adults with refractory epilepsy and a community sample and related these traits to patients' HRQOL.

METHODS

A total of 121 adults with refractory epilepsy (18-40 years old, 56% women) completed questionnaires on the Big Five personality traits, HRQOL, and seizure frequency and severity. Patients' Big Five scores were compared to those of a community sample matched on sex and age using paired samples t-tests. We conducted hierarchical regression analyses to examine associations between personality and HRQOL, while controlling for the effects of sex, age, age at diagnosis, seizure frequency, and seizure severity.

RESULTS

Patients reported higher levels of neuroticism and lower levels of openness as compared to controls. In patients, seizure severity was positively related to neuroticism and negatively related to agreeableness. Finally, patients high in neuroticism and low in conscientiousness generally reported a poorer HRQOL.

CONCLUSION

In the present study, small personality differences were observed between adults with refractory epilepsy and a community sample. Patients' personality was found to play an important role in adjusting to epilepsy, even after controlling for seizure frequency and severity. Personality assessment may help healthcare professionals in identifying patients at risk for poor HRQOL later in life.

Big Five Personality Traits and Life Satisfaction: The Mediating Role of Religiosity

Extensive empirical research conducted up till now has confirmed that personality represents one of the most significant predictors of life satisfaction. Still, no studies to date have empirically tested the path of influence from personality traits to religiosity and the effects of both on life satisfaction/positivity within the same model. In the current study, we aimed to verify whether the relationship between personality and satisfaction/positivity was mediated by religiousness, as it is considered motivational in nature. The sample consisted of 213 participants (72% women) aged between 18 and 75. The average age was approx. 32. We used the following tools: the NEO Five Factor Inventory, the Satisfaction with Life Scale, the Positivity Scale, the Personal Religiousness Scale, and the Intensity of Religious Attitude Scale. Our hypotheses (H1 and H2) found their confirmation to a large degree. In fact, life satisfaction positively correlated with extraversion, agreeableness, and conscientiousness. Moreover, life satisfaction negatively correlated with neuroticism. A similar pattern of results, even slightly stronger, was found in the case of positivity and personality traits. Contrary to our assumptions, neither life satisfaction nor positivity correlated with openness to experience. Extraversion and agreeableness correlated positively with religious attitude, personal religiousness and its four dimensions. Conscientiousness correlated positively only with faith, personal religiousness, and religious attitude. We also found negative and significant correlations between openness and all of the dimensions of personal religiousness. A lack of correlation was found between: (1) neuroticism and all of the dimensions of religiosity; (2) conscientiousness and religious practices, and religious self. Our research offers a contribution to the field by providing evidence that some personality traits predict life satisfaction/positivity because respondents display a personal religiousness/religious attitude.