Here we test the feasibility of using decision markets to select studies for replication and provide evidence about the replicability of online experiments. Social scientists (n = 162) traded on the outcome of close replications of 41 systematically selected MTurk social science experiments published in PNAS 2015–2018, knowing that the 12 studies with the lowest and the 12 with the highest final market prices would be selected for replication, along with 2 randomly selected studies. The replication rate, based on the statistical significance indicator, was 83% for the top-12 and 33% for the bottom-12 group. Overall, 54% of the studies were successfully replicated, with replication effect size estimates averaging 45% of the original effect size estimates. The replication rate varied between 54% and 62% for alternative replication indicators. The observed replicability of MTurk experiments is comparable to that of previous systematic replication projects involving laboratory experiments.
Social media have enabled laypersons to disseminate, at scale, links to news and public affairs information. Many individuals share such links without first reading the linked information. Here we analysed over 35 million public Facebook posts with uniform resource locators shared between 2017 and 2020, and discovered that such ‘shares without clicks’ (SwoCs) constitute around 75% of forwarded links. Extreme and user-aligned political content received more SwoCs, with partisans engaging in it more than politically neutral users. In addition, analyses with 2,969 false uniform resource locators revealed higher shares and, hence, SwoCs by conservatives (76.94%) than liberals (14.25%), probably because, in our dataset, the vast majority (76–82%) of them originated from conservative news domains. Findings suggest that the virality of political content on social media (including misinformation) is driven by superficial processing of headlines and blurbs rather than systematic processing of core content, which has design implications for promoting deliberate discourse in the online public sphere.
Public trust in scientists is critical to our ability to face societal threats. Here, across five pre-registered studies (N = 2,034), we assessed whether perceptions of scientists’ intellectual humility affect perceived trustworthiness of scientists and their research. In study 1, we found that seeing scientists as higher in intellectual humility was associated with greater perceived trustworthiness of scientists and support for science-based beliefs. We then demonstrated that describing a scientist as high (versus low) in intellectual humility increased perceived trustworthiness of the scientist (studies 2–4), belief in their research (studies 2–4), intentions to follow their research-based recommendations (study 3) and information-seeking behaviour (study 4). We further demonstrated that these effects were not moderated by the scientist’s gender (study 3) or race/ethnicity (study 4). In study 5, we experimentally tested communication approaches that scientists can use to convey intellectual humility. These studies reveal the benefits of seeing scientists as intellectually humble across medical, psychological and climate science topics.
The Internet is increasingly important in addressing age-related mental health challenges. We used linear mixed models and meta-analyses to examine the association between Internet use and mental health among 87,559 adults aged ≥50 years from 23 countries. Internet use was associated with fewer depressive symptoms (pooled average marginal effect (AME), -0.09; 95% confidence interval (CI), -0.12 to -0.07), higher life satisfaction (pooled AME, 0.07; 95% CI, 0.05 to 0.10) and better self-reported health (pooled AME, 0.15; 95% CI, 0.12 to 0.17). For two countries (the USA and England) with genetic data available, positive associations between Internet use and mental health were observed across three genetic risk categories. For three countries (the USA, England and China), a higher frequency of Internet use was related to better mental health. Our findings are relevant to public health policies and practices in promoting mental health in later life through the Internet, especially in countries with limited Internet access and mental health services.
Young adults from low socioeconomic backgrounds face an increased risk of early mortality. Here we utilize population-wide data from 17 Norwegian birth cohorts (N = 986,573) to assess whether this risk gradient was explained by early-life educational performance, specifically grade point average at 16 years of age. We show that the gradients in both parental education and income largely disappeared when adjusting for school performance in the models. Specifically, among boys, those with the lowest parental education had an unadjusted hazard ratio (HR) of 2.04 (95% confidence interval (CI) 1.86–2.22) compared with peers with the highest parental education, while for girls, the HR was 1.64 (95% CI 1.35–1.93). After adjusting for school performance, these estimates dropped to 0.99 (95% CI 0.79–1.19) for boys and 0.87 (95% CI 0.55–1.19) for girls. Similarly, the mortality risk for those from the lowest parental income quartile decreased from 1.79 (95% CI 1.67–1.91) to 1.25 (95% CI 1.12–1.38) for boys and from 1.63 (95% CI 1.44–1.83) to 1.24 (95% CI 1.03–1.46) for girls. Low educational performance remained strongly associated with early mortality in analyses accounting for unobserved heterogeneity at the family level; boys with a grade point average in the lowest quartile had an HR of 3.04 (95% CI 2.38–3.89), while for girls, the HR was 1.79 (95% CI 1.22–2.63). External causes of death, particularly accidents and poisoning, were most overrepresented among individuals with poor school performance.
Integrating proteomic and transcriptomic data with genetic architectures of problematic alcohol use and alcohol consumption behaviours can advance our understanding and help identify therapeutic targets. We conducted systematic screens using genome-wise association study data from ~3,500 cortical proteins (N = 722) and ~6,100 genes in 8 canonical brain cell types (N = 192) with 4 alcohol-related outcomes (N ≤ 537,349), identifying 217 cortical proteins and 255 cell-type genes associated with these behaviours, with 36 proteins and 37 cell-type genes being new. Although there was limited overlap between proteome and transcriptome targets, downstream neuroimaging revealed shared neurophysiological pathways. Colocalization with independent genome-wise association study data further prioritized 16 proteins, including CAB39L and NRBP1, and 12 cell-type genes, implicating mechanisms such as mTOR signalling. In addition, genes such as SAMHD1, VIPAS39, NUP160 and INO80E were identified as having favourable neuropsychiatric profiles. These findings provide insights into the genetic landscapes governing problematic alcohol use and alcohol consumption behaviours, highlighting promising therapeutic targets for future research.