Emotional (in)stability: Neuroticism is associated with increased variability in negative emotion after all.

The personality trait neuroticism is tightly linked to mental health, and neurotic people experience stronger negative emotions in everyday life. But, do their negative emotions also show greater fluctuation? This commonsensical notion was recently questioned by [Kalokerinos et al. Proc Natl Acad Sci USA 112, 15838-15843 (2020)], who suggested that the associations found in previous studies were spurious. Less neurotic people often report very low levels of negative emotion, which is usually measured with bounded rating scales. Therefore, they often pick the lowest possible response option, which severely constrains the amount of emotional variability that can be observed in principle. Applying a multistep statistical procedure that is supposed to correct for this dependency, [Kalokerinos et al. Proc Natl Acad Sci USA 112, 15838-15843 (2020)] no longer found an association between neuroticism and emotional variability. However, like other common approaches for controlling for undesirable effects due to bounded scales, this method is opaque with respect to the assumed mechanism of data generation and might not result in a successful correction. We thus suggest an alternative approach that a) takes into account that emotional states outside of the scale bounds can occur and b) models associations between neuroticism and both the mean and variability of emotion in a single step with the help of Bayesian censored location-scale models. Simulations supported this model over alternative approaches. We analyzed 13 longitudinal datasets (2,518 individuals and 11,170 measurements in total) and found clear evidence that more neurotic people experience greater variability in negative emotion.

Neuroticism/Negative Emotionality Is Associated with Increased Reactivity to Uncertain Threat in the Bed Nucleus of the Stria Terminalis, Not the Amygdala.

Neuroticism/negative emotionality (N/NE)-the tendency to experience anxiety, fear, and other negative emotions-is a fundamental dimension of temperament with profound consequences for health, wealth, and well-being. Elevated N/NE is associated with a panoply of adverse outcomes, from reduced socioeconomic attainment to psychiatric illness. Animal research suggests that N/NE reflects heightened reactivity to uncertain threat in the bed nucleus of the stria terminalis (BST) and central nucleus of the amygdala (Ce), but the relevance of these discoveries to humans has remained unclear. Here we used a novel combination of psychometric, psychophysiological, and neuroimaging approaches to test this hypothesis in an ethnoracially diverse, sex-balanced sample of 220 emerging adults selectively recruited to encompass a broad spectrum of N/NE. Cross-validated robust-regression analyses demonstrated that N/NE is preferentially associated with heightened BST activation during the uncertain anticipation of a genuinely distressing threat (aversive multimodal stimulation), whereas N/NE was unrelated to BST activation during certain-threat anticipation, Ce activation during either type of threat anticipation, or BST/Ce reactivity to threat-related faces. It is often assumed that different threat paradigms are interchangeable assays of individual differences in brain function, yet this has rarely been tested. Our results revealed negligible associations between BST/Ce reactivity to the anticipation of threat and the presentation of threat-related faces, indicating that the two tasks are nonfungible. These observations provide a framework for conceptualizing emotional traits and disorders; for guiding the design and interpretation of biobank and other neuroimaging studies of psychiatric risk, disease, and treatment; and for refining mechanistic research.

Serum cortisol and neuroticism for post-traumatic stress disorder over 2 years in patients with physical injuries.

AIM: This study aimed to explore the relationships between serum cortisol levels, personality traits, and the development of Post-Traumatic Stress Disorder (PTSD) over 2 years among individuals with physical injuries. METHODS: Participants were consecutively recruited from a trauma center and followed prospectively for 2 years. At baseline, serum cortisol levels were measured, and personality traits were categorized into five dimensions (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness), using the Big Five Inventory-10. The diagnosis of PTSD during follow-up (at 3, 6, 12, and 24 months post-injury) was determined using the Clinician-Administered PTSD Scale for DSM-5. Binary and multinomial logistic regression analyses were conducted to examine the interactions between cortisol levels, personality traits, and PTSD development. RESULTS: Among 923 patients analyzed, 112 (12.1%) were diagnosed with PTSD at some point during the study period, with prevalence rates decreasing from 8.8% at 3 months to 3.7% at 24 months post-injury. Direct associations between cortisol levels or personality traits and PTSD were not observed. However, a significant interaction between lower cortisol levels and higher Neuroticism in relation to PTSD risk was identified, especially during the early follow-up periods (3 to 6 months), but this association waned from the 12-month follow-up onward. CONCLUSION: Our findings reveal Neuroticism-dependent associations between serum cortisol levels and PTSD development, exhibiting temporal variations. These results suggest that PTSD development may be influenced by a complex, time-sensitive interplay of biological and psychosocial factors, underscoring the importance of considering individual differences in stress reactivity and personality in PTSD research and treatment.

Neuroticism may not reflect emotional variability.

Neuroticism is one of the major traits describing human personality, and a predictor of mental and physical disorders with profound public health significance. Individual differences in emotional variability are thought to reflect the core of neuroticism. However, the empirical relation between emotional variability and neuroticism may be partially the result of a measurement artifact reflecting neuroticism's relation with higher mean levels-rather than greater variability-of negative emotion. When emotional intensity is measured using bounded scales, there is a dependency between variability and mean levels: at low (or high) intensity, it is impossible to demonstrate high variability. As neuroticism is positively associated with mean levels of negative emotion, this may account for the relation between neuroticism and emotional variability. In a metaanalysis of 11 studies (N = 1,205 participants; 83,411 observations), we tested whether the association between neuroticism and negative emotional variability was clouded by a dependency between variability and the mean. We found a medium-sized positive association between neuroticism and negative emotional variability, but, when using a relative variability index to correct for mean negative emotion, this association disappeared. This indicated that neuroticism was associated with experiencing more intense, but not more variable, negative emotions. Our findings call into question theory, measurement scales, and data suggesting that emotional variability is central to neuroticism. In doing so, they provide a revisionary perspective for understanding how this individual difference may predispose to mental and physical disorders.

Causal Effects of Positive Affect, Life Satisfaction, Depressive Symptoms, and Neuroticism on Kidney Function: A Mendelian Randomization Study.

BACKGROUND: Further investigation of the causal effects of psychologic wellbeing on kidney function is warranted. METHODS: In this Mendelian randomization (MR) study, genetic instruments for positive affect, life satisfaction, depressive symptoms, and neuroticism were introduced from a previous genome-wide association study meta-analysis of European individuals. Summary-level MR was performed using the CKDGen data of European ancestry (n=567,460), and additional allele score-based MR was performed in the individual-level data of White British UK Biobank participants (n=321,024). RESULTS: In summary-level MR with the CKDGen data, depressive symptoms were a significant causative factor for kidney function impairment (CKD OR, 1.45; 95% confidence interval, 1.07 to 1.96; eGFR change [%] beta -2.18; 95% confidence interval, -3.61 to -0.72) and pleiotropy-robust sensitivity analysis results supported the causal estimates. A genetic predisposition for positive affect was significantly associated with better kidney function (CKD OR, 0.69; 95% confidence interval, 0.52 to 0.91), eGFR change [%] beta 1.50; 95% confidence interval, 0.09 to 2.93) and sensitivity MR analysis results supported the finding for CKD outcome, but was nonsignificant for eGFR. Life satisfaction and neuroticism exposures showed nonsignificant causal estimates. In the UK Biobank with covariate-adjusted allele score MR analysis, allele scores for positive affect and life satisfaction were causally associated with reduced risk of CKD and higher eGFR. In contrast, neuroticism allele score was associated with increased risk of CKD and lower eGFR, and depressive symptoms allele score was associated with lower eGFR, but showed nonsignificant association with CKD. CONCLUSIONS: Health care providers in the nephrology field should be aware of the causal linkage between psychologic wellbeing and kidney function.

Brain structural connectivity, anhedonia, and phenotypes of major depressive disorder: A structural equation model approach.

Aberrant brain structural connectivity in major depressive disorder (MDD) has been repeatedly reported, yet many previous studies lack integration of different features of MDD with structural connectivity in multivariate modeling approaches. In n = 595 MDD patients, we used structural equation modeling (SEM) to test the intercorrelations between anhedonia, anxiety, neuroticism, and cognitive control in one comprehensive model. We then separately analyzed diffusion tensor imaging (DTI) connectivity measures in association with those clinical variables, and finally integrated brain connectivity associations, clinical/cognitive variables into a multivariate SEM. We first confirmed our clinical/cognitive SEM. DTI analyses (FWE-corrected) showed a positive correlation of anhedonia with fractional anisotropy (FA) in the right anterior thalamic radiation (ATR) and forceps minor/corpus callosum, while neuroticism was negatively correlated with axial diffusivity (AD) in the left uncinate fasciculus (UF) and inferior fronto-occipital fasciculus (IFOF). An extended SEM confirmed the associations of ATR FA with anhedonia and UF/IFOF AD with neuroticism impacting on cognitive control. Our findings provide evidence for a differential impact of state and trait variables of MDD on brain connectivity and cognition. The multivariate approach shows feasibility of explaining heterogeneity within MDD and tracks this to specific brain circuits, thus adding to better understanding of heterogeneity on the biological level.

Stability of nightmare frequency and its relation to neuroticism: A longitudinal study.

Models of nightmare aetiology postulate an interaction between trait and state factors. However, most of the studies that support these models have been cross-sectional and longitudinal studies are scarce. The present data were obtained from N = 888 participants completing two online dream studies carried out independently with the same online panel 2 years apart. Nightmare frequency declined over the 2-year period and these changes were related to changes in neuroticism. The effect of current psychopathology (state aspect) on nightmare frequency was significant but much smaller compared to the effect of previously measured nightmare frequency (trait aspect) and, thus, the study provided empirical evidence for diathesis-stress models. Future longitudinal studies should take a closer look at life events and other factors that increase and/or decrease nightmare frequencies.

Is neuroticism relevant for old cancer survivors? A controlled, population-based study (the Norwegian HUNT-3 survey).

PURPOSE: Personality traits, particularly neuroticism, have an impact on people's health and lifestyle. Due to lack of previous studies, we examined old cancer survivors (OCSs) versus cancer-free age-matched controls aged ≥ 70 years, regarding prevalence of high neuroticism, health problems in those with high and low neuroticism, and sociodemographic and clinical variables that were significantly associated with high neuroticism. METHODS: We merged data from a Norwegian population-based health study (the HUNT-3) and from the Cancer Registry of Norway identifying OCSs. Three cancer-free controls were drawn at random for each OCS. Neuroticism was self-rated on a brief version of Eysenck Personality Questionnaire. Between-group statistical comparisons were made between OCS and controls, and among their subgroups with high and low neuroticism. Logistic regression analyses were used to investigate independent variables significantly associated with high neuroticism. RESULTS: Twenty-nine percent of OCSs reported high neuroticism while controls reported 30%. OCSs showed significantly lower rate of good life satisfaction than controls. All other between-group comparisons were nonsignificant. Being OCSs was not significantly related to high neuroticism in the regression analyses. Sociodemographic, general health, and lifestyle issues, lack of energy, and low life satisfaction remained significantly associated with high neuroticism in the multivariable analysis. CONCLUSIONS: The prevalence of high neuroticism was similar in OCSs and controls. High neuroticism was associated with negative health and lifestyle issues in both groups.

Personality Traits and Emotional Word Recognition: An ERP Study.

Recent research has investigated how personality trait differences influence the processing of emotion conveyed by pictures, but limited research has examined the emotion conveyed by words. The present study investigated whether extraversion (extroverts vs. introverts) and neuroticism (high neurotics vs. low neurotics) influence the processing of positive, neutral, and negative words that were matched for arousal. Electroencephalography (EEG) was recorded from healthy participants while they performed a lexical decision task. We found that personality traits influenced emotional word recognition at N400 (300-450 ms) and LPC (450-800 ms). At the earlier (N400) stage, the more extraverted and neurotic a participant was, the more reduced the N400s for the positive words relative to neutral words were. This suggests that the extroverts and high neurotics (i.e., high impulsivity) identified positive content in words during lexical feature retrieval, which facilitated such retrieval. At the later (LPC) stage, both the introverts and high neurotics (i.e., high anxiety) showed greater LPCs to negative than neutral words, indicating their sustained attention and elaborative processing of negative information. These results suggest that extraversion and neuroticism collectively influence different stages of emotional word recognition in a way that is consistent with Gray's biopsychological theory of personality.

How intelligence and emotional control are related to suicidal behavior across the life course - A register-based study with 38-year follow-up.

BACKGROUND: Both low intelligence and low emotional control have previously been linked to a higher risk of suicide, but it is unknown whether the associations apply consistently over the life course. METHODS: The study was based on data on intelligence and emotional control, collected from 48 738 Swedish men conscripted in 1969-1970, at ages 18-20 years. The data were linked to national registers giving information on subsequent suicidal behavior (completed and attempted suicide) up to the age of 59 years. The associations were investigated using logistic regression and Cox proportional hazards regression models, with adjustment for childhood socioeconomic status. RESULTS: Intelligence and emotional control assessed in late adolescence both showed robust inverse associations with suicidal behavior over the 38-year follow-up. However, while the association between lower intelligence and higher rate of suicidal behavior remained the same throughout (~40% increased hazard per unit on a five-level scale), the association between lower emotional control and suicidal behavior was substantially stronger in early adulthood (~100% increased hazard per unit) than in late middle age (~30% increased hazard per unit). CONCLUSIONS: The study adds to previous research by showing that the association between poor emotional control and subsequent suicide risk in men becomes weaker over the life course, while the association between low intelligence and suicide risk seems to be constant. The particularly high suicide risk of young men with poor emotional control may motivate targeted prevention efforts.

Familial Influences on Neuroticism and Education in the UK Biobank.

Genome-wide studies often exclude family members, even though they are a valuable source of information. We identified parent-offspring pairs, siblings and couples in the UK Biobank and implemented a family-based DNA-derived heritability method to capture additional genetic effects and multiple sources of environmental influence on neuroticism and years of education. Compared to estimates from unrelated individuals, total heritability increased from 10 to 27% and from 17 to 56% for neuroticism and education respectively by including family-based genetic effects. We detected no family environmental influences on neuroticism. The couple similarity variance component explained 35% of the variation in years of education, probably reflecting assortative mating. Overall, our genetic and environmental estimates closely replicate previous findings from an independent sample. However, more research is required to dissect contributions to the additional heritability by rare and structural genetic effects, assortative mating, and residual environmental confounding. The latter is especially relevant for years of education, a highly socially contingent variable, for which our heritability estimate is at the upper end of twin estimates in the literature. Family-based genetic effects could be harnessed to improve polygenic prediction.

Neuroticism in temporal lobe epilepsy is associated with altered limbic-frontal lobe resting-state functional connectivity.

Neuroticism, a core personality trait characterized by a tendency towards experiencing negative affect, has been reported to be higher in people with temporal lobe epilepsy (TLE) compared with healthy individuals. Neuroticism is a known predictor of depression and anxiety, which also occur more frequently in people with TLE. The purpose of this study was to identify abnormalities in whole-brain resting-state functional connectivity in relation to neuroticism in people with TLE and to determine the degree of unique versus shared patterns of abnormal connectivity in relation to elevated symptoms of depression and anxiety. Ninety-three individuals with TLE (55 females) and 40 healthy controls (18 females) from the Epilepsy Connectome Project (ECP) completed measures of neuroticism, depression, and anxiety, which were all significantly higher in people with TLE compared with controls. Resting-state functional connectivity was compared between controls and groups with TLE with high and low neuroticism using analysis of variance (ANOVA) and t-test. In secondary analyses, the same analytics were performed using measures of depression and anxiety and the unique variance in resting-state connectivity associated with neuroticism independent of symptoms of depression and anxiety identified. Increased neuroticism was significantly associated with hyposynchrony between the right hippocampus and Brodmann area (BA) 9 (region of prefrontal cortex (PFC)) (p < 0.005), representing a unique relationship independent of symptoms of depression and anxiety. Hyposynchrony of connection between the right hippocampus and BA47 (anterior frontal operculum) was associated with high neuroticism and with higher depression and anxiety scores (p < 0.05), making it a shared abnormal connection for the three measures. In conclusion, increased neuroticism exhibits both unique and shared patterns of abnormal functional connectivity with depression and anxiety symptoms between regions of the mesial temporal and frontal lobe.

Mood Instability and Trait Anxiety as Distinct Components of Eysenckian Neuroticism With Differential Relations to Impulsivity and Risk Taking.

This article presents the results of 2 studies that investigated mood instability in the Eysenck neuroticism scales and its relationship to trait impulsivity and risk taking. In Study 1 we examined the relationship between a mood instability factor in the Eysenck Personality Inventory and impulsivity (i.e., rapid unplanned behavior) in a general population sample of 6,066 adults. The mood instability factor was positively correlated with impulsivity. The remaining factors, largely reflecting trait anxiety, were also positively correlated with impulsivity, although these correlations disappeared when mood instability was included in the same regression model. In Study 2 we factor analyzed the short form of the revised Eysenck Personality Questionnaire to isolate mood instability and trait anxiety factors and explore their associations with risk taking in a general population sample of 394,170 adults 40 to 69 years old. The mood instability factor was positively associated with risk taking, whereas the association for the trait anxiety factor was negative. Taken together, the results suggest that mood instability and trait anxiety are separable components of Eysenckian neuroticism and that mood instability is the main component that is positively associated with trait impulsivity and risk taking. Further research is needed to clarify the factor structure of Eysenckian neuroticism.

Association between personality traits and elder abuse in a community-dwelling Chinese population: findings from the PINE study.

Elder abuse is a pervasive public health issue. The relationship between personality traits and elder abuse remains unclear. This study aims to examine the associations between neuroticism, conscientiousness, and elder abuse. Data were derived from the Population Study of Chinese Elderly (PINE), a community-engaged study of 3,157 US Chinese older adults in the greater Chicago area from 2011-2013. Elder abuse included psychological, physical, and sexual abuse, financial exploitation, and caregiver neglect. The assessments of neuroticism and conscientiousness were derived from the NEO Five-Factor Inventory. Logistic regression was used. Higher neuroticism (score range: 6-30, OR = 1.14, CI = 1.11-1.18) and lower conscientiousness (score range: 16-60, OR = 0.97, CI = 0.96-0.99) were associated with a higher risk of elder abuse. With respect to different forms of elder abuse, higher neuroticism was associated with an increased risk of psychological abuse (OR = 1.14, CI = 1.10-1.17), financial exploitation (OR = 1.03, CI = 1.00-1.07), and caregiver neglect (OR = 1.06, CI = 1.03-1.09). Higher conscientiousness was associated with a higher risk of financial exploitation (OR = 1.02, CI = 1.00-1.05). Intervention programs could reduce neuroticism and raise conscientiousness of elder abuse victims.

A Mendelian randomization study of the causal association between anxiety phenotypes and schizophrenia.

Schizophrenia shows a genetic correlation with both anxiety disorder and neuroticism, a trait strongly associated with anxiety. However, genetic correlations do not discern causality from genetic confounding. We therefore aimed to investigate whether anxiety-related phenotypes lie on the causal pathway to schizophrenia using Mendelian randomization (MR). Four MR methods, each with different assumptions regarding instrument validity, were used to investigate casual associations of anxiety and neuroticism related phenotypes on schizophrenia, and vice versa: inverse variance weighted (IVW), weighted median, weighted mode, and, when appropriate, MR Egger regression. MR provided evidence of a causal effect of neuroticism on schizophrenia (IVW odds ratio [OR]: 1.33, 95% confidence interval [CI]: 1.12-1.59), but only weak evidence of a causal effect of anxiety on schizophrenia (IVW OR: 1.10, 95% CI: 1.01-1.19). There was also evidence of a causal association from schizophrenia liability to anxiety disorder (IVW OR: 1.28, 95% CI: 1.18-1.39) and worry (IVW beta: 0.05, 95% CI: 0.03-0.07), but effect estimates from schizophrenia to neuroticism were inconsistent in the main analysis. The evidence of neuroticism increasing schizophrenia risk provided by our results supports future efforts to evaluate neuroticism- or anxiety-based therapies to prevent onset of psychotic disorders.

Maternal environmental risk factors and the development of internalizing and externalizing problems in childhood: The complex role of genetic factors.

The development of problem behavior in children is associated with exposure to environmental factors, including the maternal environment. Both are influenced by genetic factors, which may also be correlated, that is, environmental risk and problem behavior in children might be influenced by partly the same genetic factors. In addition, environmental and genetic factors could interact with each other increasing the risk of problem behavior in children. To date, limited research investigated these mechanisms in a genome-wide approach. Therefore, the goal of this study was to investigate the association between genetic risk for psychiatric and related traits, as indicated by polygenetic risk scores (PRSs), exposure to previously identified maternal risk factors, and problem behavior in a sample of 1,154 children from the Amsterdam Born Children and their Development study at ages 5-6 and 11-12 years old. The PRSs were derived from genome-wide association studies (GWASs) on schizophrenia, major depressive disorder, neuroticism, and wellbeing. Regression analysis showed that the PRSs were associated with exposure to multiple environmental risk factors, suggesting passive gene-environment correlation. In addition, the PRS based on the schizophrenia GWAS was associated with externalizing behavior problems in children at age 5-6. We did not find any association with problem behavior for the other PRSs. Our results indicate that genetic predispositions for psychiatric disorders and wellbeing are associated with early environmental risk factors for children's problem behavior.

Modeling prior information of common genetic variants improves gene discovery for neuroticism.

Neuroticism reflects emotional instability, and is related to various mental and physical health issues. However, the majority of genetic variants associated with neuroticism remain unclear. Inconsistent genetic variants identified by different genome-wide association studies (GWAS) may be attributable to low statistical power. We proposed a novel framework to improve the power for gene discovery by incorporating prior information of single nucleotide polymorphisms (SNPs) and combining two relevant existing tools, relative enrichment score (RES) and conditional false discovery rate (FDR). Here, SNP's conditional FDR was estimated given its RES based on SNP prior information including linkage disequilibrium (LD)-weighted genic annotation scores, total LD scores and heterozygosity. A known significant locus in chromosome 8p was excluded before estimating FDR due to long-range LD structure. Only one significant LD-independent SNP was detected by analyses of unconditional FDR and traditional GWAS in the discovery sample (N = 59 225), and notably four additional SNPs by conditional FDR. Three of the five SNPs, all identified by conditional FDR, were replicated (P < 0.05) in an independent sample (N = 170 911). These three SNPs are located in intronic regions of CADM2, LINGO2 and EP300 which have been reported to be associated with autism, Parkinson's disease and schizophrenia, respectively. Our approach using a combination of RES and conditional FDR improved power of traditional GWAS for gene discovery providing a useful framework for the analysis of GWAS summary statistics by utilizing SNP prior information, and helping to elucidate the links between neuroticism and complex diseases from a genetic perspective.

Neuroticism as a Predictor of Frailty in Old Age: A Genetically Informative Approach.

OBJECTIVE: Neuroticism is associated with poor health outcomes, but its contribution to the accumulation of health deficits in old age, that is, the frailty index, is largely unknown. We aimed to explore associations between neuroticism and frailty cross-sectionally and longitudinally, and to investigate the contribution of shared genetic influences. METHODS: Data were derived from the UK Biobank (UKB; n = 274,951), the Australian Over 50's Study (AO50; n = 2849), and the Swedish Twin Registry (Screening Across the Lifespan of Twins Study [SALT], n = 18,960; The Swedish Adoption/Twin Study of Aging [SATSA], n = 1365). Associations between neuroticism and the frailty index were investigated using regression analysis cross-sectionally in UKB, AO50, and SATSA and longitudinally in SALT (25-29 years of follow-up) and SATSA (6 and 23 years of follow-up). The co-twin control method was applied to explore the contribution of underlying shared familial factors (SALT, SATSA, AO50). Genome-wide polygenic risk scores for neuroticism were used in all samples to further assess whether common genetic variants associated with neuroticism predict frailty. RESULTS: High neuroticism was consistently associated with greater frailty cross-sectionally (adjusted ß [95% confidence intervals] in UKB = 0.32 [0.32-0.33]; AO50 = 0.35 [0.31-0.39]; SATSA = 0.33 [0.27-0.39]) and longitudinally up to 29 years (SALT = 0.24 [0.22-0.25]; SATSA 6 years = 0.31 [0.24-0.38]; SATSA 23 years = 0.16 [0.07-0.25]). When adjusting for underlying shared genetic and environmental factors, the neuroticism-frailty association remained significant, although decreased. Polygenic risk scores for neuroticism significantly predicted frailty in the two larger samples (meta-analyzed total ß = 0.059 [0.055-0.062]). CONCLUSIONS: Neuroticism in midlife predicts frailty in late life. Neuroticism may have a causal influence on frailty, whereas both environmental and genetic influences, including neuroticism-associated common genetic variants, contribute to this relationship.

The relationship between neuroticism and appetitive conditioning.

Appetitive conditioning is considered a central mechanism for the vulnerability to psychiatric disorders. However, the investigation of individual differences that are related to altered appetitive learning has been almost neglected so far. The aim of this study was to investigate the link between neuroticism and appetitive conditioning processes. 79 subjects participated in a differential conditioning procedure in which a conditioned stimulus (CS+) was paired with a reward (money) after a fast behavioral response, while a second conditioned stimulus (CS-) was never followed by a reward, irrespective of the behavioral response. As a main result, neuroticism correlated negatively with the underlying neural processes of appetitive conditioning in females, but not in males. In detail, higher levels of neuroticism were associated with decreased neural responses in the left (p = .001) and right amygdala (p = .011), left (p = .063) and right (p = .019) nucleus accumbens, and left (p = .002) and right (p = .021) orbitofrontal cortex (all results are family-wise-error-corrected). The present results support previous findings, which also showed an inverse sex-specific effect in the context of neuroticism and emotional processing in females. In addition, the findings suggest that neuroticism is not solely linked to increased amygdala sensitivity during the processing of negative stimuli but also to decreased neural responses when processing rewarding stimuli. Possible explanations for the sex differences and implications are discussed.

Do People Know What They're Like in the Moment?

Knowing yourself requires knowing not only what you are like in general (trait self-knowledge) but also how your personality fluctuates from moment to moment (state self-knowledge). We examined this latter form of self-knowledge. Participants (248 people; 2,938 observations) wore the Electronically Activated Recorder (EAR), an unobtrusive audio recorder, and completed experience-sampling self-reports of their personality states four times each day for 1 week. We estimated state self-knowledge by comparing self-reported personality states with consensual observer ratings of personality states coded from the EAR files, which formed the criterion for what participants were "actually" like in the moment. People had self-insight into their momentary extraversion, conscientiousness, and likely neuroticism, suggesting that people can accurately detect fluctuations in some aspects of their personality. However, the evidence for self-insight was weaker for agreeableness. This apparent self-ignorance may be partly responsible for interpersonal problems and for blind spots in trait self-knowledge.