The power of social influence: A replication and extension of the Asch experiment.

In this paper, we pursue four goals: First, we replicate the original Asch experiment with five confederates and one naïve subject in each group (N = 210). Second, in a randomized trial we incentivize the decisions in the line experiment and demonstrate that monetary incentives lower the error rate, but that social influence is still at work. Third, we confront subjects with different political statements and show that the power of social influence can be generalized to matters of political opinion. Finally, we investigate whether intelligence, self-esteem, the need for social approval, and the Big Five are related to the susceptibility to provide conforming answers. We find an error rate of 33% for the standard length-of-line experiment which replicates the original findings by Asch (1951, 1955, 1956). Furthermore, in the incentivized condition the error rate decreases to 25%. For political opinions we find a conformity rate of 38%. However, besides openness, none of the investigated personality traits are convincingly related to the susceptibility of group pressure.

The Effects of Non-pharmaceutical Interventions on COVID-19 Mortality: A Generalized Synthetic Control Approach Across 169 Countries.

Importance: Governments have introduced non-pharmaceutical interventions (NPIs) in response to the pandemic outbreak of Coronavirus disease (COVID-19). While NPIs aim at preventing fatalities related to COVID-19, the previous literature on their efficacy has focused on infections and on data of the first half of 2020. Still, findings of early NPI studies may be subject to underreporting and missing timeliness of reporting of cases. Moreover, the low variation in treatment timing during the first wave makes identification of robust treatment effects difficult. Objective: We enhance the literature on the effectiveness of NPIs with respect to the period, the number of countries, and the analytical approach. Design Setting and Participants: To circumvent problems of reporting and treatment variation, we analyse data on daily confirmed COVID-19-related deaths per capita from Our World in Data, and on 10 different NPIs from the Oxford COVID-19 Government Response Tracker (OxCGRT) for 169 countries from 1st July 2020 to 1st September 2021. To identify the causal effects of introducing NPIs on COVID-19-related fatalities, we apply the generalized synthetic control (GSC) method to each NPI, while controlling for the remaining NPIs, weather conditions, vaccinations, and NPI-residualized COVID-19 cases. This mitigates the influence of selection into treatment and allows to model flexible post-treatment trajectories. Results: We do not find substantial and consistent COVID-19-related fatality-reducing effects of any NPI under investigation. We see a tentative change in the trend of COVID-19-related deaths around 30 days after strict stay-at-home rules and to a slighter extent after workplace closings have been implemented. As a proof of concept, our model is able to identify a fatality-reducing effect of COVID-19 vaccinations. Furthermore, our results are robust with respect to various crucial sensitivity checks. Conclusion: Our results demonstrate that many implemented NPIs may not have exerted a significant COVID-19-related fatality-reducing effect. However, NPIs might have contributed to mitigate COVID-19-related fatalities by preventing exponential growth in deaths. Moreover, vaccinations were effective in reducing COVID-19-related deaths.

Healthy nutrition in Germany: a survey analysis of social causes, obesity and socioeconomic status.

OBJECTIVE: The obesity pandemic is an increasing burden for society. Information on key drivers of the nutrition cycle of (a) social causation, (b) biological causation and (c) health selection is vital for effective policies targeted at the reduction of obesity prevalence. However, empirical causal knowledge on (a) the social predictors of diet quality, (b) its impact on corpulence and (c) the socioeconomic consequences of obesity is sparse. We overcome the limitations of previous research and acquire comprehensive causal insight into this cycle. DESIGN: Therefore, we analyse two German socio-epidemiological panel surveys exploiting their longitudinal panel structure utilising hybrid panel regression models. SETTING: General population of Germany. PARTICIPANTS: German Health Interview and Examination Survey for Children and Adolescents (KiGGS, n 17 640; age 0-24 years) and the German National Nutrition Monitoring (NEMONIT, n 2610; age 15-82 years). RESULTS: The results indicate that (a) interestingly only sex, education and age explain healthy diets; (b) increases in a newly developed Optimised Healthy Eating Index (O-HEI-NVSII) and in nuts intake reduce BMI, while growing overall energy intake, lemonade, beer and meat (products) intake drive corpulence; (c) in turn, developing obesity decreases socioeconomic status. CONCLUSIONS: These results suggest that policies targeted at the reduction of obesity prevalence may be well advised to focus on boys and men, people with low education, the promotion of a healthy diet and nuts intake, and the limitation of lemonade, beer and meat (products) intake. Therefore, future research may focus on the replication of our findings utilising longer panels and experimental approaches.

Mechanisms of perfect absorption in nano-composite systems.

Recently, it was noted that losses in plasmonics can also enable several useful optical functionalities. One class of structures that can maximize absorption are metal insulator metal systems. Here, we study 3-layer systems with a nano-composite metal layer as top layer. These systems can absorb almost 100% of light at visible frequencies, even though they contain only dielectrics and highly reflecting metals. We elucidate the underlying physical phenomenon that leads to this extraordinary high and broadband absorption. A comprehensive study of the particle material and shape, mirror material and dielectric spacer thickness is provided to identify their influence on the overall absorption. Thus, we can provide detailed design guidelines for realizing optical functionalities that require near-perfect absorption over specific wavelength bands. Our results reveal the strong role of lossy Fabry-Perot interference within these systems despite their thickness being well below half a wavelength.

Contagious yawning, empathy, and their relation to prosocial behavior.

Humans express facial mimicry across a variety of actions. This article explores a distinct example, contagious yawning, and the links to empathy and prosocial behavior. Prior studies have suggested that there is a positive link between empathy and the susceptibility to contagious yawning. However, the existing evidence has been sparse and contradictory. We present results from 2 laboratory studies conducted with 171 (Study 1) and 333 (Study 2) student volunteers. Subjects were video-recorded while watching muted videos of individuals yawning, scratching, or laughing. Empathy was measured using the Interpersonal Reactivity Index. Although subjects imitated all facial expressions to large extents, our studies show that only contagious yawning was related to empathy. Subjects who yawned in response to observing others yawn exhibited higher empathy values by half a standard deviation. However, we found no evidence that the susceptibility to contagious yawning is directly related to prosocial behavior. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The native microbiome of the nematode Caenorhabditis elegans: gateway to a new host-microbiome model.

BACKGROUND: Host-microbe associations underlie many key processes of host development, immunity, and life history. Yet, none of the current research on the central model species Caenorhabditis elegans considers the worm's natural microbiome. Instead, almost all laboratories exclusively use the canonical strain N2 and derived mutants, maintained through routine bleach sterilization in monoxenic cultures with an E. coli strain as food. Here, we characterize for the first time the native microbiome of C. elegans and assess its influence on nematode life history characteristics. RESULTS: Nematodes sampled directly from their native habitats carry a species-rich bacterial community, dominated by Proteobacteria such as Enterobacteriaceae and members of the genera Pseudomonas, Stenotrophomonas, Ochrobactrum, and Sphingomonas. The C. elegans microbiome is distinct from that of the worm's natural environment and the congeneric species C. remanei. Exposure to a derived experimental microbiome revealed that bacterial composition is influenced by host developmental stage and genotype. These experiments also showed that the microbes enhance host fitness under standard and also stressful conditions (e.g., high temperature and either low or high osmolarity). Taking advantage of the nematode's transparency, we further demonstrate that several Proteobacteria are able to enter the C. elegans gut and that an Ochrobactrum isolate even seems to be able to persist in the intestines under stressful conditions. Moreover, three Pseudomonas isolates produce an anti-fungal effect in vitro which we show can contribute to the worm's defense against fungal pathogens in vivo. CONCLUSION: This first systematic analysis of the nematode's native microbiome reveals a species-rich bacterial community to be associated with C. elegans, which is likely of central importance for our understanding of the worm's biology. The information acquired and the microbial isolates now available for experimental work establishes C. elegans as a tractable model for the in-depth dissection of host-microbiome interactions.