Objectives: Mindfulness is associated with the different forms of motivation according to self-determination theory (intrinsic, identified, and external motivation, and amotivation). However, causal evidence for reported negative associations of mindfulness with external motivation and amotivation is currently lacking. Therefore, this study investigated causal effects of a brief mindfulness intervention on motivation towards a personal goal. We differentiated distinct forms of motivation and also controlled for baseline motivation and trait mindfulness, which could act as a moderator of the interventional effects. Methods: Data of N = 91 participants were used, who were randomly assigned to either audio-guided meditation or a control condition. Situational motivation for a personal goal was assessed before and after the intervention. Trait mindfulness was measured with the Five Facet Mindfulness Questionnaire. Results: The intervention had a positive effect on the more autonomous forms of motivation (d = 0.48), which was, however, qualified by trait mindfulness; i.e., the effect was larger among participants low in trait mindfulness (d = 1.13 at 1 SD below the overall mean). There were no practically relevant effects on external motivation and amotivation. Conclusions: Mindfulness has a positive causal effect on more autonomous forms of motivation, but probably no relevant effects on external motivation and amotivation. Moderating effects of trait mindfulness need to be considered more systematically in this field of research, but also in research of mindfulness intervention more generally. Mindfulness interventions could be beneficially offered to persons low in trait mindfulness.

In recent years, an ostensible Mozart effect, suggesting beneficial influences of listening to the sonata KV448 on epilepsy, has been extensively covered in popular media outlets. However, the evidential value of such a potential effect seems unclear. Here, we present the first formal meta-analysis on this topic, based on k = 8 studies (N = 207). Further published studies that met our inclusion criteria had to be omitted due to insufficient reporting and author non-responsiveness on data requests. In three independent analyses, we observed non-significant trivial-to-small summary effects for listening to Mozart KV448 or other musical stimuli on epilepsy or other medical conditions (g range: 0.09–0.43). Bias and sensitivity analyses suggested that these effects were likely inflated and non-trivial effects were driven by isolated leverage points. Multiverse analyses conformed to these results, showing inconsistent evidential patterns. Low primary study power and consequently lacking evidential value indicates that there is only little reason to suspect a specific Mozart effect. In all, listening to music, let alone a specific kind of sonata, does not appear to have any beneficial effect on epilepsy. Unfounded authority, underpowered studies, and non-transparent reporting appear to be the main drivers of the Mozart effect myth.

Is lower intelligence in early life an overlooked risk factor for later physical and mental illness? Intelligence shapes decision-making, career paths, and other health-relevant factors. However, our understanding of its association with health remains limited because there is no quantitative synthesis of the literature. Here, we conducted a comprehensive systematic review and meta-analysis of associations between intelligence test scores and mental and physical health. We included studies reporting standardized intelligence test scores obtained in childhood, adolescence, or early adulthood ( 2,900,000) showed a 15-point IQ disadvantage in early life was associated with a 22 percent higher risk of later mental and physical illness (logHR = 0.20, 95% CI [0.13, 0.26]). Lower IQ predicted disease risk across various conditions, including schizophrenia, depression, dementia, and diabetes. Notably, the association between IQ and future health diminished with improved healthcare quality and when education was statistically held constant. Nevertheless, a meaningful effect of intelligence remained after adjusting for these variables. Multiple methods for detecting dissemination bias indicated that risk of bias was low. While our summary effect estimates are precise, all included data were collected in highly developed nations. Further, samples were predominantly male, potentially limiting generalizability. We show that lower IQ scores in early life are linked to a higher risk of later physical and mental illness. Improving education and healthcare quality appears as potential measures to address the issue. This research received no specific funding.

The effectiveness of cloth face masks to prevent viral spread has not yet been conclusively established. In this meta-analysis, we evaluate their effectiveness in comparison to standard medical/surgical and N95-typed masks against viral spread. We identified literature through a systematic search in three databases and meta-analytically synthesized relevant studies by means of random-effects as well as multilevel modelling. Twelve studies comprising k = 28 effect sizes (N = 338) were included. Medical/surgical and N95-typed masks outperformed cloth masks, yielding a large effect (g = 1.40). This effect remained robust when data were grouped according to comparisons with medical/surgical masks (g = 1.25) and N95-typed masks (g = 1.29). However, effects were differentiated according to mask fit, indicating reversals of signs when cloth mask effects were compared with ill-fitting medical/surgical and N95-typed masks (gs = −12.50 and − 10.90, respectively). Cloth face masks were found to have significantly poorer filtering performance than medical/surgical masks and N95 masks, but only if non-cloth masks were properly fitted. Our results illustrate the necessity of using well-fitting medical/surgical or N95-typed masks to prevent viral spread, although some allowance should be made in circumstances where higher compliance with cloth mask mandates are expected.

Objective: Several recent accounts have failed to replicate the so‐called Narcissism Epidemic, suggesting potential influences of the Global Financial Crisis (GFC) in 2008 as a reason for narcissism trend reversals. Here, we provide evidence for narcissism test score changes from 1982 to 2023.Methods: We investigated self‐report data on the Narcissistic Personality Inventory (NPI) from 1105 studies (k = 1621, N = 546,225) using precision‐weighted cross‐temporal meta‐analysis.Results: Data collection years were meaningfully negatively associated with narcissism scores in virtually all analyses (bs: −0.409 to −0.008; partial eta square's: < 0.001 to 0.118; ps: < 0.001 to 0.174), thus indicating cross‐temporally decreasing narcissism self‐report scores. Examination of regression segments pre‐ and post‐dating the GFC and segmented line regressions indicated mostly stable narcissism scores during the 1980s and 1990s that subsequently showed negative slopes with somewhat differing decreases onsets according to analytical subsets.Conclusions: Here, we provide evidence for negative cross‐temporal changes in narcissism from 1982 to 2023 globally, thus contrasting the idea of a Narcissism Epidemic having taken place at any point during the past four decades. Changes appear to generalize across different regions and participant sex, although mean scores were differentiated, yielding higher narcissism values for North American and younger samples.