Disentangling periodic and aperiodic resting EEG correlates of personality.

Previous studies of resting electroencephalography (EEG) correlates of personality traits have conflated periodic and aperiodic sources of EEG signals. Because these are associated with different underlying neural dynamics, disentangling them can avoid measurement confounds and clarify findings. In a large sample (n = 300), we investigated how disentangling these activities impacts findings related to two research programs within personality neuroscience. In Study 1 we examined associations between Extraversion and two putative markers of reward sensitivity-Left Frontal Alpha asymmetry (LFA) and Frontal-Posterior Theta (FPT). In Study 2 we used machine learning to predict personality trait scores from resting EEG. In both studies, power within each EEG frequency bin was quantified as both total power and separate contributions of periodic and aperiodic activity. In Study 1, total power LFA and FPT correlated negatively with Extraversion (r ∼ -0.14), but there was no relation when LFA and FPT were derived only from periodic activity. In Study 2, all Big Five traits could be decoded from periodic power (r ∼ 0.20), and Agreeableness could also be decoded from total power and from aperiodic indices. Taken together, these results show how separation of periodic and aperiodic activity in resting EEG may clarify findings in personality neuroscience. Disentangling these signals allows for more reliable findings relating to periodic EEG markers of personality, and highlights novel aperiodic markers to be explored in future research.

Why moral psychology needs personality psychology.

People vary in how they perceive, think about, and respond to moral issues. Clearly, we cannot fully understand the psychology of morality without accounting for individual differences in moral functioning. But decades of neglect of and explicit skepticism toward such individual differences has resulted in a lack of integration between moral psychology and personality psychology-the study of psychological differences between people. In recent years, these barriers to progress have started to break down. This special issue aims to celebrate and further increase the visibility of the personality psychology of morality. Here, we introduce the articles in this special issue by highlighting some important contributions a personality-based perspective has to offer moral psychology-particularly in comparison to the currently prominent social psychological approach. We show that personality psychology is well-placed to (a) contribute toward a rigorous empirical foundation for moral psychology, (b) tackle the conceptualization and assessment of stable moral tendencies, (c) assess the predictive validity of moral traits in relation to consequential outcomes, (d) uncover the mechanisms underlying individual differences in moral judgments and behavior, and (e) provide insights into moral development. For these reasons, we believe that moral psychology needs personality psychology to reach its full scholarly potential.

Psychological well-being in Europe after the outbreak of war in Ukraine.

The Russian invasion of Ukraine on February 24, 2022, has had devastating effects on the Ukrainian population and the global economy, environment, and political order. However, little is known about the psychological states surrounding the outbreak of war, particularly the mental well-being of individuals outside Ukraine. Here, we present a longitudinal experience-sampling study of a convenience sample from 17 European countries (total participants = 1,341, total assessments = 44,894, countries with >100 participants = 5) that allows us to track well-being levels across countries during the weeks surrounding the outbreak of war. Our data show a significant decline in well-being on the day of the Russian invasion. Recovery over the following weeks was associated with an individual's personality but was not statistically significantly associated with their age, gender, subjective social status, and political orientation. In general, well-being was lower on days when the war was more salient on social media. Our results demonstrate the need to consider the psychological implications of the Russo-Ukrainian war next to its humanitarian, economic, and ecological consequences.

Characterizing subdomains of insistence on sameness in autistic youth.

Insistence on sameness (IS) encompasses a range of behavioral patterns, including resistance to change, routines, and ritualized behaviors, that can be present across social and non-social contexts. Given the breadth of behaviors encompassed by IS, it is important to determine whether this domain is best conceptualized and measured as uni- or a multi-dimensional construct. Therefore, the current study aimed to characterize the structure of IS and explore potentially distinct of patterns of associations between identified IS factors and relevant correlates, including age, sex, IQ, anxiety, social abilities, emotional and behavioral dysregulation, and sensory hypersensitivity. Exploratory graph analysis was conducted using the dimensional assessment of restricted and repetitive behaviors to examine the structure of IS in a sample 1892 autistic youth (Mage = 10.82, SDage = 4.14; range: 3-18 years; 420 females) recruited from the Simons Foundation Powering Autism Research for Knowledge cohort. Three distinct IS subdomains labeled as IS-Ritualistic/sameness, IS-Routines, and IS-Others (referring to IS behaviors during interactions with others) were identified. Generalized additive models demonstrated that each of the IS subdomains showed a unique pattern of association with key variables. More specifically, while sensory hypersensitivity was significantly associated with IS-Ritualistic/sameness and IS-Routines, it was not associated with IS-Others. Further, while emotional dysregulation was a unique predictor of IS-Ritualistic/sameness (but not IS-Routines or IS-Others), social interaction abilities were a unique predictor of IS-Routines (but not IS-Ritualistic/sameness or IS-Others). Current findings provide preliminary evidence that the IS may encompass several distinct subdomains.

Differential responses to ethical vegetarian appeals: Exploring the role of traits, beliefs, and motives.

OBJECTIVE: This research examines differential responses to ethical vegetarian appeals as a fuction of individuals' personalities. BACKGROUND: Ethical vegetarian appeals are persuasive messages promoting the adoption of a plant-based diet on moral grounds. Individuals may vary in their receptivity to such appeals, depending on their morally relevant traits (e.g., agreeableness), beliefs (e.g., speciesism), and motives (e.g., concerns about animal welfare). METHODS: We explored (Study 1, N = 907) and then attempted to confirm (Study 2, N = 980) differential responses to three vegetarian appeals-two highlighting moral concerns (animal welfare, the environment) and a third focusing on individual health (control condition). RESULTS: Both studies revealed several differential effects of our vegetarian appeals on the perceived effectiveness of the appeal and resultant intentions to reduce meat consumption. These mostly consisted of differences in receptivity to appeals focused on animal welfare. However, only one such effect observed in Study 1 was clearly replicated in Study 2: People who more strongly believed that eating meat was "normal" rated the vegetarian appeals focused on animal welfare as less effective. CONCLUSION: Ethical vegetarian appeals may elicit different responses from different people, particularly those focused on animal welfare, depending on how normative one believes meat-eating to be. Such insights can inform behavior change efforts in this area.

Profiles of circumscribed interests in autistic youth.

Circumscribed interests (CI) encompass a range of different interests and related behaviors that can be characterized by either a high intensity but otherwise usual topic [referred to as restricted interests (RI)] or by a focus on topics that are not salient outside of autism [referred to as unusual interests (UI)]. Previous research has suggested that there is pronounced variability across individuals in terms of the endorsement of different interests, however, this variability has not been quantified using formal subtyping approaches. Therefore, using Latent Profile Analysis in a sample of 1,892 autistic youth (Mage = 10.82, SDage = 4.14; 420 females), this study aimed to identify subgroups based on the RU and UI profiles. Three profiles of autistic individuals were identified. They were characterized as Low CI, Predominantly RI, and Predominantly UI. Importantly, profiles differed on several key demographic and clinical variables, including age, sex composition, IQ, language level, social and communication abilities, anxiety, and obsessive-compulsive behaviors. Although replication across other samples is needed, the profiles identified in this study are potentially promising for future research given their distinct profiles of RI and UI and unique patterns of associations with key cognitive and clinical variables. Therefore, this study represents an important initial step towards more individualized assessment and support for diverse presentations of CI in autistic youth.

Evaluating the effectiveness of vegetarian appeals in daily life: Comparing positive and negative imagery, and gauging differential responses.

Persuasive appeals designed to reduce meat consumption often employ graphic images of the harms perpetuated by eating meat (e.g., cruel factory farming practices). However, because people are motivated to see themselves as moral, appeals that highlight omnivores' moral failings might be resisted or even backfire. Furthermore, individuals differ in ways that may influence their motivations and attitudes toward animals and meat-eating, and their responses to these appeals. Thus, in a two-week intervention study (N = 427), we compared effects of two vegetarian appeals-one employing graphic negative imagery (footage of factory farming cruelty), the other employing positive imagery (footage from farmed animal sanctuaries)-on daily meat consumption and related affects and cognitions. We also examined several personality traits and other individual differences that may confer differential effects of these appeals. Although neither appeal significantly reduced meat consumption, both the positive and negative appeal increased intentions to eat less meat, and led to more negative affect and cognition when eating meat. Moreover, several individual difference variables moderated the effects of these appeals on actual and intended meat consumption. Findings are discussed in relation to the difficulty of changing morally troublesome behaviour, and the use of graphic appeals despite their unclear impact on behaviour.

Characterizing restricted and unusual interests in autistic youth.

A broad range of interests characterized by unusual content and/or intensity, labeled as circumscribed interests (CI), are a core diagnostic feature of autism. Recent evidence suggests that a distinction can be drawn between interests that, although characterized by unusually high intensity and/or inflexibility, are otherwise common in terms of their content (e.g., an interest in movies or animals), labeled as restricted interests (RI), and interests that are generally not salient outside of autism (e.g., an interest in traffic lights or categorization), labeled as unusual interests (UI). The current study aimed to further characterize RI and UI by exploring their association with age, sex, IQ, and social motivation, as well as to examine differences in the adaptive benefits and negative impacts of these two subdomains. Parents of 1892 autistic children and adolescents (Mage  = 10.82, SDage  = 4.14; 420 females) completed an online survey including the Dimensional Assessment of Restricted and Repetitive Behaviors and the Social Communication Questionnaire. Both RI and UI were found to be highly frequent. Sex-based differences were observed in the content, but not intensity, of CI such that females were more likely to show interests with a social component. Finally, RI and UI showed distinct patterns of association with age, sex, IQ, and social motivation, as well as metrics of adaptive benefits and negative impacts. Findings afford a more nuanced understanding of sex-based differences in CI and, crucially, provide preliminary evidence that RI and UI represent distinct constructs that should be studied independently in future research.

Personality traits beyond Neuroticism predict post-concussive symptomatology in the post-acute period after mild traumatic brain injury in premorbidly healthy adults.

There is growing evidence that an individual's personality traits are related to post-concussion symptomatology beyond the acute period after mild traumatic brain injury (mTBI). Few studies, however, have analyzed this impact beyond the personality trait of Neuroticism. We examined the impact of personality traits on post-concussion symptoms (PCS) by measuring the Big Five personality domains and their lower-order aspects in 87 pre-morbidly healthy participants assessed 6-12 weeks post-mTBI (n = 53) or physical trauma (n = 34). As expected, Neuroticism predicted PCS endorsement in both groups. Conscientiousness and Openness/intellect were predictive of lower PCS endorsement, but only in the mTBI group. Withdrawal, one aspect within the Neuroticism domain, independently predicted PCS endorsement in the mTBI group; the remaining Neuroticism aspect, Volatility, did not predict PCS endorsement in either group. These findings suggest that individuals high in Neuroticism are more likely to report PCS following mTBI and that this relationship is driven by susceptibility to depression/anxiety symptoms (Withdrawal aspect) rather than irritability (Volatility aspect). Further, they suggest that the current focus on the relationship between Neuroticism and PCS reporting in individuals with mTBI should be broadened to include other personality domains, such as Conscientiousness and Openness/intellect.

Personality Neuroscience: An Emerging Field with Bright Prospects.

Personality neuroscience is the study of persistent psychological individual differences, typically in the general population, using neuroscientific methods. It has the potential to shed light on the neurobiological mechanisms underlying individual differences and their manifestation in ongoing behavior and experience. The field was inaugurated many decades ago, yet has only really gained momentum in the last two, as suitable technologies have become widely available. Personality neuroscience employs a broad range of methods, including molecular genetics, pharmacological assays or manipulations, electroencephalography, and various neuroimaging modalities, such as magnetic resonance imaging and positron emission tomography. Although exciting progress is being made in this young field, much remains unknown. In this brief review, we discuss discoveries that have been made, methodological challenges and advances, and important questions that remain to be answered. We also discuss best practices for personality neuroscience research and promising future directions for the field.

Evaluating the Big Five as an organizing framework for commonly used psychological trait scales.

The Big Five is often represented as an effective taxonomy of psychological traits, yet little research has empirically examined whether stand-alone assessments of psychological traits can be located within the Big Five framework. Meanwhile, construct proliferation has created difficulty navigating the resulting landscape. In the present research, we developed criteria for assessing whether the Big Five provides a comprehensive organizing framework for psychological trait scales and evaluated this question across three samples (Total N = 1,039). Study 1 revealed that 83% of an author-identified collection of scales (e.g., Self-Esteem, Grit, etc.) were as related to the Big Five as at least four of 30 Big Five facets, and Study 2 found that 71% of scales selected based on citation counts passed the same criterion. Several scales had strikingly large links at the Big Five facet level, registering correlations with individual Big Five facets exceeding .9. We conclude that the Big Five can indeed serve as an organizing framework for a sizable majority of stand-alone psychological trait scales and that many of these scales could reasonably be labeled as facets of the Big Five. We suggest an integrative pluralism approach, where reliable, valid scales are located within the Big Five and pertinent Big Five research is considered in all research using trait scales readily located within the Big Five. By adopting such an approach, construct proliferation may be abated and it would become easier to integrate findings from disparate fields. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

From ordinary to extraordinary: A roadmap for studying the psychology of moral exceptionality.

Some moral actions - including prosocial actions - are more exceptional than others. Within psychology, interest in such moral exceptionality is mounting, but a definition of the concept is lacking. Our review addresses this issue by integrating insights from the moral exemplar, heroism, and supererogation literatures. We propose an action-based definition that places the outperformance of prescriptive or descriptive moral norms at the core of moral exceptionality. Using our definition, we i) discuss how exceptionality is represented in moral constructs studied across psychology and ii) provide a template for identifying moral exceptionality in the prosocial domain.

Why do people seek information? The role of personality traits and situation perception.

The opportunity to learn new knowledge is ever present. How do people decide if information has sufficient value to counteract the cost of obtaining it? We proposed a conceptual model of information seeking that emphasizes how personality traits and perceptions of situations may influence motivations to seek information to explore (related to trait curiosity and openness/intellect, and situations evoking more positive emotions and opportunities for intellectual engagement) or feel safe (related to trait uncertainty intolerance and neuroticism, and situations that evoke more negative emotions). Across two studies (N = 436; N = 316), information seeking was assessed with two widely used paradigms (advance knowledge of a reward outcome and answers to trivia questions), as well as two variations of the trivia paradigm in Study 1. In all contexts, the available information was noninstrumental, having no practical utility within the context of the task. Consistent with our proposed exploration pathway, curiosity and openness/intellect predicted the choice to seek information for trivia and related stimuli, but not reward-outcome stimuli, and trivia stimuli were generally rated as more intellectually engaging, more positive, and less negative than reward-outcome stimuli. However, evidence for the safety pathway was only partially in line with predictions, with uncertainty intolerance predicting reward-outcome information seeking in Study 2 only. We consider possible modifications to our initial model and implications for information-seeking research. These studies provide a proof of concept that people display both trait- and context-dependent preferences for noninstrumental information, both of which are commonly overlooked in studies of information seeking. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Does openness/intellect predict sensitivity to the reward value of information?

A recent theory proposes that the personality trait openness/intellect is underpinned by differential sensitivity to the reward value of information. This theory draws on evidence that midbrain dopamine neurons respond to unpredicted information gain, mirroring their responses to unpredicted primary rewards. Using a choice task modelled on this seminal work (Experiment 1, N = 139, 69% female), we examined the relation between openness/intellect and willingness to pay for non-instrumental information (i.e., information with no secondary utility). We also assessed whether any such relation was moderated by the dopamine D2 receptor antagonist sulpiride (Experiment 2, N = 164, 100% male). Unexpectedly, most measures of openness/intellect were unrelated to costly information preference in both experiments, and some predicted a decreased willingness to incur a cost for information. In Experiment 2, this cost-dependent association between openness/intellect and information valuation appeared in the placebo condition but not under sulpiride. In addition, participants were more willing to pay for moderately costly information under sulpiride compared to placebo, consistent with a dopaminergic basis to information valuation. Potential refinements to the information valuation theory of openness/intellect are discussed in the light of these and other emerging findings.

Who gives a veg? Relations between personality and Vegetarianism/Veganism.

With rates of vegetarianism and veganism (i.e., veg*nism) rising around the world, a growing body of research has begun to explore psychological characteristics that distinguish vegetarians and vegans from omnivores. However, relatively few studies have examined how veg*nism is related to differences in basic personality traits such as the "Big Five", with those that have tending to yield conflicting results. Moreover, none of these studies have examined personality at the lower levels of the personality trait hierarchy (i.e., aspects and facets of the Big Five). Thus, we sought to clarify how personality traits are related to veg*nism. In Study 1, comprising two samples (S1a: N = 797, S1b: N = 1534), participants were categorised as Veg*n vs Restricted-omnivore vs Omnivore, and completed personality questionnaires at the domain and aspect levels of the Big Five. In Study 2, participants (N = 562) completed both categorical and continuous measures of veg*nism, along with personality questionnaires at the domain, aspect, and facet levels. Across both studies, we found that people who scored higher on traits within the openness/intellect and agreeableness domains most consistently reported higher levels of veg*nism. Patterns in the data also suggested that the relation between personality and veg*nism might depend on the way veg*nism is measured. Theoretical and practical implications of these findings are discussed.

Why Has Personality Psychology Played an Outsized Role in the Credibility Revolution?

Personality is not the most popular subfield of psychology. But, in one way or another, personality psychologists have played an outsized role in the ongoing "credibility revolution" in psychology. Not only have individual personality psychologists taken on visible roles in the movement, but our field's practices and norms have now become models for other fields to emulate (or, for those who share Baumeister's (2016, https://doi.org/10.1016/j.jesp.2016.02.003) skeptical view of the consequences of increasing rigor, a model for what to avoid). In this article we discuss some unique features of our field that may have placed us in an ideal position to be leaders in this movement. We do so from a subjective perspective, describing our impressions and opinions about possible explanations for personality psychology's disproportionate role in the credibility revolution. We also discuss some ways in which personality psychology remains less-than-optimal, and how we can address these flaws.

Anxious and obsessive-compulsive traits are independently associated with valuation of noninstrumental information.

Aversion to uncertainty about the future has been proposed as a transdiagnostic trait underlying psychiatric diagnoses including obsessive-compulsive disorder and generalized anxiety. This association might explain the frequency of pathological information-seeking behaviors such as compulsive checking and reassurance-seeking in these disorders. Here we tested the behavioral predictions of this model using a noninstrumental information-seeking task that measured preferences for unusable information about future outcomes in different payout domains (gain, loss, and mixed gain/loss). We administered this task, along with a targeted battery of self-report questionnaires, to a general-population sample of 146 adult participants. Using computational cognitive modeling of choices to test competing theories of information valuation, we found evidence for a model in which preferences for costless and costly information about future outcomes were independent, and in which information preference was modulated by both outcome mean and outcome variance. Critically, we also found positive associations between a model parameter controlling preference for costly information and individual differences in latent traits of both anxiety and obsessive-compulsion. These associations were invariant across different payout domains, providing evidence that individuals high in obsessive-compulsive and anxious traits show a generalized increase in willingness-to-pay for unusable information about uncertain future outcomes, even though this behavior reduces their expected future reward. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Personality and moral judgment: Curious consequentialists and polite deontologists.

OBJECTIVE: How does our personality relate to the ways in which we judge right from wrong? Drawing on influential theories of moral judgment, we identify candidate traits that may be linked with inclinations toward (a) consequentialist judgments (i.e., those based on the outcomes of an action) and (b) deontological judgments (i.e., those based on the alignment of an action with particular moral rules). METHOD: Across two studies (total N = 843) we examined domains and aspects of the Big Five in relation to inclinations toward consequentialist and deontological judgments. RESULTS: In both studies, we found a unique association between intellect (curiosity, cognitive engagement) and consequentialist inclinations, in line with the view that deliberative cognitive processes drive such inclinations. We also found a consistent unique association between politeness (respectfulness, etiquette) and deontological inclinations, in line with the view that norm-adherence drives such inclinations. Neither study yielded a significant unique relation between deontological inclinations and compassion (sympathy, empathic concern)-or any other emotion-infused trait (e.g., Neuroticism)-as would be expected based on emotion-centered views of deontological moral judgment. CONCLUSIONS: These findings have implications for theories of moral judgment, and reveal how our personality may guide our approach to questions of ethics and morality.

Decoding personality trait measures from resting EEG: An exploratory report.

Can personality be predicted from oscillatory patterns produced by the brain at rest? To date, relatively few studies using electroencephalography (EEG) have yielded consistent relations between personality trait measures and spectral power. Thus, new exploratory research may help develop targeted hypotheses about how neural processes associated with EEG activity may relate to personality differences. We used multivariate pattern analysis to decode personality scores (i.e., Big Five traits) from resting EEG frequency power spectra. Up to 8 minutes of EEG data was recorded per participant prior to completing an unrelated task (N = 168, Mage = 23.51, 57% female) and, in a subset of participants, after task completion (N = 96, Mage = 23.22, 52% female). In each recording, participants alternated between open and closed eyes. Linear support vector regression with 10-fold cross validation was performed using the power from 62 scalp electrodes within 1 Hz frequency bins from 1 to 30 Hz. One Big Five trait, agreeableness, could be decoded from EEG power ranging from 8 to 19 Hz, and this was consistent across all four recording periods. Neuroticism was decodable using data within the 3-6 Hz range, albeit less consistently. Posterior alpha power negatively correlated with agreeableness, whereas parietal beta power positively correlated with agreeableness. We suggest methods to draw from our results and develop targeted future hypotheses, such as linking to individual alpha frequency and incorporating self-reported emotional states. Our open dataset can be harnessed to reproduce results or investigate new research questions concerning the biological basis of personality.

Predicting psychological and subjective well-being from personality: A meta-analysis.

This study reports the most comprehensive assessment to date of the relations that the domains and facets of Big Five and HEXACO personality have with self-reported subjective well-being (SWB: life satisfaction, positive affect, and negative affect) and psychological well-being (PWB: positive relations, autonomy, environmental mastery, purpose in life, self-acceptance, and personal growth). It presents a meta-analysis (n = 334,567, k = 462) of the correlations of Big Five and HEXACO personality domains with the dimensions of SWB and PWB. It provides the first meta-analysis of personality and well-being to examine (a) HEXACO personality, (b) PWB dimensions, and (c) a broad range of established Big Five measures. It also provides the first robust synthesis of facet-level correlations and incremental prediction by facets over domains in relation to SWB and PWB using 4 large data sets comprising data from prominent, long-form hierarchical personality frameworks: NEO PI-R (n = 1,673), IPIP-NEO (n = 903), HEXACO PI-R (n = 465), and Big Five Aspect Scales (n = 706). Meta-analytic results highlighted the importance of Big Five neuroticism, extraversion, and conscientiousness. The pattern of correlations between Big Five personality and SWB was similar across personality measures (e.g., BFI, NEO, IPIP, BFAS, Adjectives). In the HEXACO model, extraversion was the strongest well-being correlate. Facet-level analyses provided a richer description of the relationship between personality and well-being, and clarified differences between the two trait frameworks. Prediction by facets was typically around 20% better than domains, and this incremental prediction was larger for some well-being dimensions than others. (PsycINFO Database Record (c) 2020 APA, all rights reserved).