Publications by authors named "Luke D Smillie"

Linking neurobiology to relatively stable individual differences in cognition, emotion, motivation, and behavior can require large sample sizes to yield replicable results. Given the nature of between-person research, sample sizes at least in the hundreds are likely to be necessary in most neuroimaging studies of individual differences, regardless of whether they are investigating the whole brain or more focal hypotheses. However, the appropriate sample size depends on the expected effect size.

View Article and Find Full Text PDF

Manifestations of insistence on sameness (IS) and circumscribed interests (CI) are complex, with individuals varying considerably, not only in the types of behaviours they express, but also in terms of a behaviour's frequency, intensity, trajectory, adaptive benefits, and impacts. However, current quantitative RRB instruments capture only certain aspects of these behaviours (e.g.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 (M = 10.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Persuasive appeals designed to reduce meat consumption often employ graphic images of the harms perpetuated by eating meat (e.g., cruel factory farming practices).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 = 1,039).

View Article and Find Full Text PDF

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 (related to trait curiosity and openness/intellect, and situations evoking more positive emotions and opportunities for intellectual engagement) or (related to trait uncertainty intolerance and neuroticism, and situations that evoke more negative emotions). Across two studies ( = 436; = 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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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 ( = 53) or physical trauma ( = 34).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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).

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Trait extraversion has been theorized to emerge from functioning of the dopaminergic reward system. Recent evidence for this view shows that extraversion modulates the scalp-recorded Reward Positivity, a putative marker of dopaminergic signaling of reward-prediction-error. We attempt to replicate this association amid several improvements on previous studies in this area, including an adequately-powered sample (N = 100) and thorough examination of convergent-divergent validity.

View Article and Find Full Text PDF

Objective: The extensive use of two diverging personality taxonomies (the Big Five and HEXACO models) in contemporary research creates a need for understanding how traits connect to each other across taxonomies. Previous research has approached this at both a highly general (domain-) level as well as at a highly specific (facet-) level. The present report is the first to use the intermediate (aspect-) level of the Big Five Aspect Scales (BFAS) to understand the connections between the two models.

View Article and Find Full Text PDF

Evidence suggests that extraverted (i.e., bold, agentic) behavior increases positive affect (PA), and could be targeted in wellbeing interventions.

View Article and Find Full Text PDF