Social and emotional loneliness and self‐reported difficulty initiating and maintaining sleep (DIMS) in a sample of Norwegian university students

Social and emotional loneliness negatively impact several areas of health, including sleep. However, few comprehensive population‐based studies have evaluated this relationship. Over 12,000 students aged 21–35 years who participated in the student survey for higher education in Norway (the SHoT study) were assessed. Loneliness was assessed using the Social and Emotional Loneliness Scale. Difficulty initiating and maintaining sleep (DIMS) was assessed by a single‐item subjective response on the depression scale of the Hopkins Symptoms Checklist (HSCL‐25). Social loneliness was associated with more serious DIMS (unadjusted proportional odds‐ratio [OR] = 2.69, 95% CI = 2.46–2.95). This association was attenuated following adjustment for anxiety (adjusted OR = 1.92, 95% CI = 1.75–2.10) and depression (adjusted OR = 1.48, 95% CI = 1.34–1.63), however was not substantially altered when all demographics and psychological distress were accounted for (fully adjusted OR = 1.46, 95% CI = 1.30–1.63). Emotional loneliness was also associated with more serious DIMS (unadjusted proportional OR = 2.33, 95% CI = 2.12–2.57). Adjustment for anxiety (adjusted OR = 1.96, 95% CI = 1.78–2.15) and depression (adjusted OR = 1.64, 95% CI = 1.48–1.80) attenuated, but did not extinguish this relationship in the fully adjusted model (adjusted OR = 1.22, 95% CI = 1.09–1.31). Mediation analyses revealed that the social loneliness‐DIMS association was fully attributed to psychological distress, while the emotional loneliness‐DIMS association was only partially mediated, and a direct association was still observed. Associations between social and emotional loneliness and subjective DIMS were embedded in a larger pattern of psychological distress. Mitigating underlying feelings of loneliness may reduce potentially deleterious effects on sleep health and psychological wellbeing in young adults.     

Interactions between Callous Unemotional Behaviors and Executive Function in Early Childhood Predict later Aggression and Lower Peer-liking in Late-childhood

Callous unemotional (CU) behaviors are linked to aggression, behavior problems, and difficulties in peer relationships in children and adolescents. However, few studies have examined whether early childhood CU behaviors predict aggression or peer-rejection during late-childhood or potential moderation of this relationship by executive function. The current study examined whether the interaction of CU behaviors and executive function in early childhood predicted different forms of aggression in late-childhood, including proactive, reactive, and relational aggression, as well as how much children were liked by their peers. Data from cross-informant reports and multiple observational tasks were collected from a high-risk sample (N = 240; female = 118) at ages 3 and 10 years old. Parent reports of CU behaviors at age 3 predicted teacher reports of reactive, proactive, and relational aggression, as well as lower peer-liking at age 10. Moderation analysis showed that specifically at high levels of CU behaviors and low levels of observed executive function, children were reported by teachers as showing greater reactive and proactive aggression, and were less-liked by peers. Findings demonstrate that early childhood CU behaviors and executive function have unique main and interactive effects on both later aggression and lower peer-liking even when taking into account stability in behavior problems over time. By elucidating how CU behaviors and deficits in executive function potentiate each other during early childhood, we can better characterize the emergence of severe and persistent behavior and interpersonal difficulties across development.     

Serotonin enhances the impact of health information on food choice

Serotonin has been implicated in promoting self-control, regulation of hunger and physiological homeostasis, and regulation of caloric intake. However, it remains unclear whether the effects of serotonin on caloric intake reflect purely homeostatic mechanisms, or whether serotonin also modulates cognitive processes involved in dietary decision making. We investigated the effects of an acute dose of the serotonin reuptake inhibitor citalopram on choices between food items that differed along taste and health attributes, compared with placebo and the noradrenaline reuptake inhibitor atomoxetine. Twenty-seven participants attended three sessions and received single doses of atomoxetine, citalopram, and placebo in a double-blind randomised cross-over design. Relative to placebo, citalopram increased choices of more healthy foods over less healthy foods. Citalopram also increased the emphasis on health considerations in decisions. Atomoxetine did not affect decision making relative to placebo. The results support the hypothesis that serotonin may influence food choice by enhancing a focus on long-term goals. The findings are relevant for understanding decisions about food consumption and also for treating health conditions such as eating disorders and obesity.     

The impact of job complexity and performance measurement on the temporal consistency, stability, and test-retest reliability of employee job performance ratings

Although research has shown that individual job performance changes over time, the extent of such changes is unknown. In this article, the authors define and distinguish between the concepts of temporal consistency, stability, and test-retest reliability when considering individual job performance ratings over time. Furthermore, the authors examine measurement type (i.e., subjective and objective measures) and job complexity in relation to temporal consistency, stability, and test-retest reliability. On the basis of meta-analytic results, the authors found that the test-retest reliability of these ratings ranged from .83 for subjective measures in low-complexity jobs to .50 for objective measures in high-complexity jobs. The stability of these ratings over a 1-year time lag ranged from .85 to .67. The analyses also reveal that correlations between performance measures decreased as the time interval between performance measurements increased, but the estimates approached values greater than zero.     

Trait Extraversion and Dopamine Function

An influential theory within personality neuroscience suggests that trait extraversion is underpinned by individual differences in dopamine function. In a review of the relevant literature, we evaluate this theory in light of the evidence from molecular genetics, neuroimaging, and psychopharmacology. Evidence linking individual differences in extraversion with dopamine‐relevant genes, structural volume of dopamine‐rich brain regions (e.g., in striatal and ventral prefrontal areas), dopamine receptor availability, and frontal alpha asymmetry is mixed at best. Evidence concerning both scalp recorded (electroencephalogram) and hemodynamic (functional magnetic resonance imaging) neural responses to rewards appears somewhat more promising. Perhaps the best evidence concerns extraversion‐dependent responses – both neural and behavioural – to dopaminergic drugs. Future research in this area must go beyond the demonstration of theoretically consistent associations and attempt to provide more specific causal evidence for the dopamine hypothesis of extraversion. A further challenge is to expand this hypothesis to incorporate other neurobiological processes that are likely to underlie this trait.