A synthesis of evidence for policy from behavioural science during COVID-19

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations ('claims') detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms 'physical distancing' and 'social distancing'. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization.

Nudging enforcers: how norm perceptions and motives for lying shape sanctions

We conduct three studies, employing diverse methodologies (a behavioral experiment, a vignette experiment, and a norm elicitation experiment), to investigate when and how norm enforcement patterns can be modified using norm interventions in the context of dishonesty. Our preregistered, three-part data collection effort explores the extent to which norm violations are sanctioned, the impact of norm-nudges on punishment behavior, and the connection to norm perception. Using a representative sample of US participants in Study 1, we present robust evidence that norm enforcement is sensitive not only to the magnitude of the observed transgression (i.e. the size of the lie) but also to its consequences (whether the lie addresses or creates payoff inequalities). We also find that norm enforcers respond to norm-nudges conveying social information about actual lying behavior or its social disapproval. The results of a separate vignette experiment in Study 2 are consistent with the results in our behavioral experiment, thus hinting at the generalizability of our findings. To understand the interplay of norms, information about them, and punishment, we examine norm perceptions across different transgressions in Study 3. We find that norm perceptions are malleable and norm-nudges are most effective when preexisting norms are ambiguous. In sum, we show how norm enforcement can be nudged and which factors matter for doing so across various contexts and discuss their policy implications.

Competition and moral behavior: A meta-analysis of forty-five crowd-sourced experimental designs

Does competition affect moral behavior? This fundamental question has been debated among leading scholars for centuries, and more recently, it has been tested in experimental studies yielding a body of rather inconclusive empirical evidence. A potential source of ambivalent empirical results on the same hypothesis is design heterogeneity-variation in true effect sizes across various reasonable experimental research protocols. To provide further evidence on whether competition affects moral behavior and to examine whether the generalizability of a single experimental study is jeopardized by design heterogeneity, we invited independent research teams to contribute experimental designs to a crowd-sourced project. In a large-scale online data collection, 18,123 experimental participants were randomly allocated to 45 randomly selected experimental designs out of 95 submitted designs. We find a small adverse effect of competition on moral behavior in a meta-analysis of the pooled data. The crowd-sourced design of our study allows for a clean identification and estimation of the variation in effect sizes above and beyond what could be expected due to sampling variance. We find substantial design heterogeneity-estimated to be about 1.6 times as large as the average standard error of effect size estimates of the 45 research designs-indicating that the informativeness and generalizability of results based on a single experimental design are limited. Drawing strong conclusions about the underlying hypotheses in the presence of substantive design heterogeneity requires moving toward much larger data collections on various experimental designs testing the same hypothesis.

Persuading republicans and democrats to comply with mask wearing: An intervention tournament

Many people practiced COVID-19-related safety measures in the first year of the pandemic, but Republicans were less likely to engage in behaviors such as wearing masks or face coverings than Democrats, suggesting radical disparities in health practices split along political fault lines. We developed an "intervention tournament" which aimed to identify the framings that would promote mask wearing among a representative sample of Republicans and Democrats in the U.S. from Oct 14, 2020, to Jan 14, 2021 (N = 4931). Seven different conditions reflecting different moral values and factors specific to COVID-19-including protection from harm (self), protection from harm (community), patriotic duty, purity, reviving the economy, threat, and scientific evidence-were implemented to identify which framings would "win" in terms of promoting mask wearing compared to a baseline condition. We found that Republicans had significantly more negative attitudes toward masks, lower intentions to wear them, and were less likely to sign or share pledges on social media than Democrats, which was partially mediated by Republicans, compared to Democrats, perceiving that the threat of COVID-19 was lower. None of our framing conditions significantly affected Republicans' or Democrats' attitudes, intentions, or behaviors compared to the baseline condition, illustrating the difficulty in overcoming the strength of political polarization during COVID-19.

Politicizing mask-wearing: predicting the success of behavioral interventions among republicans and democrats in the U.S

Scientists and policymakers seek to choose effective interventions that promote preventative health measures. We evaluated whether academics, behavioral science practitioners, and laypeople (N = 1034) were able to forecast the effectiveness of seven different messages compared to a baseline message for Republicans and Democrats separately. These messages were designed to nudge mask-wearing attitudes, intentions, and behaviors. When examining predictions across political parties, forecasters predicted larger effects than those observed for Democrats compared to Republicans and made more accurate predictions for Republicans compared to Democrats. These results are partly driven by a lack of nudge effects on Democrats, as reported in Gelfand et al. (J Exp Soc Psychol, 2021). Academics and practitioners made more accurate predictions compared to laypeople. Although forecasters' predictions were correlated with the nudge interventions, all groups overestimated the observed results. We discuss potential reasons for why the forecasts did not perform better and how more accurate forecasts of behavioral intervention outcomes could potentially provide insight that can help save resources and increase the efficacy of interventions.

Efficient Institutions and Effective Deterrence: On Timing and Uncertainty of Formal Sanctions

Economic theory suggests that the deterrence of deviant behavior is driven by a combination of severity and certainty of punishment. This paper presents the first controlled experiment to study a third important factor that has been mainly overlooked: the swiftness of formal sanctions. We consider two dimensions: the timing at which the uncertainty about whether one will be punished is dissolved and the timing at which the punishment is actually imposed, as well as the combination thereof. By varying these dimensions of delay systematically, we find a surprising non-monotonic relation with deterrence: either no delay (immediate resolution and immediate punishment) or maximum delay (both resolution and punishment as much as possible delayed) emerge as most effective at deterring deviant behavior and recidivism. Our results yield implications for the design of institutional policies aimed at mitigating misconduct and reducing recidivism.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at doi:10.1007/s11166-021-09352-x.

The hyperglycemic effect of 1-deoxy-D-manno-heptulose. Inhibition of hexokinase, glucokinase, and insulin release in vitro

Injection of 1-deoxy-D-manno-heptulose (1-DMH, 400 mg, subcutaneously) into rats is associated with a hyperglycemia which reaches a peak after 2 h and is about half that caused by the same dose of D-manno-heptulose (MH). Insulin release from pieces of rabbit pancreas suspended in 15 mM glucose and 20 mM 1-DMH was about 20% of the release in the absence of 1-DMH. Under the same conditions MH caused a complete block of insulin release. Yeast hexokinase was inhibited to the extent of 58% and 68% by 1-DMH and MH (14.3 mM), respectively. 1-DMH is also inferior to MH as an inhibitor of crude rat liver hexokinase and glucokinase. The primary hydroxyl group on carbon-1 of MH is not required for the heptulose to exert its inhibitory effect on hexokinase.