Is it riskier to meet 100 people outdoors or 14 people indoors? Comparing public and expert perceptions of COVID-19 risk.

People have limited capacity to process and integrate multiple sources of information, so how do they integrate multiple contextual risk factors for Coronavirus disease (COVID-19) infection? In June 2020, we elicited risk perceptions from a nationally representative sample of the public (N = 800) using three psychologically-distinct tasks. Responses were compared to a sample of medical experts who completed the same tasks. Relative to experts, the public perceived lower risk associated with environmental factors (such as whether a gathering takes place indoors or outdoors) and were less inclined to treat risk factors as multiplicative. Our results are consistent with a heuristic simply to "avoid people" and with a coarse (e.g., "safe or unsafe") classification of social settings. A further task, completed only by the general public sample, generated novel evidence that when infection risk competes with risk in another domain (e.g., a different medical risk), people perceive a lower likelihood of contracting the virus. These results inform the policy response to the pandemic and have implications for understanding differences between expert and lay perception of risk. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Can Visual Cues to Portion Size Reduce the Number of Portions of Consumed? Two Randomized Controlled Trials.

BACKGROUND: Since 1950, the portion size of many snack foods has more than doubled and obesity rates have tripled. Portion size determines energy intake, often unwittingly. PURPOSE: This paper tests whether salient visual cues to portion size on the packaging of high fat, sugar, or salty (HFSS) snacks can reduce consumption. METHODS: Two preregistered randomized controlled trials (N = 253 and N = 674) measured consumption in a lab and the home environment. Cues were salient, labeled stripes that demarcated single portions. Participants were randomized to cue condition or control. Consumption was measured without awareness. RESULTS: The main preregistered effect of the visual cue was not statistically significant. There was some variation by subgroup. In Study 1, men were more likely to eat the whole can of potato chips than women but significantly reduced consumption when visual cues were on the pack. The effect size was large: the number of men eating more than the recommended portion fell by 33%. Study 2 monitored household consumption of chocolate biscuits (cookies) sent to family homes in gift packs. Again, the main effect was nonsignificant but there was significant subgroup variation. When the person receiving the biscuits was female, households were more likely to eat more than the recommended portion per person per day, but less likely when the visual cues were displayed. The gender of the eaters was not known. The effect size was again large: the number of households eating more than the recommended portion fell by 26%. Households with children were also less likely to open packs with visual cues compared to control packs. Both studies recorded significant increases in the likelihood of observing serving size information, together with confusion about what it means. CONCLUSIONS: The studies offer some evidence that salient visual cues could play a role in tackling the high consumption of unhealthy snacks, but the effects are confined to specific subgroups and warrant further investigation.

Using decision aids to support self-isolation during the COVID-19 pandemic.

OBJECTIVE: Self-isolation is a vital element of efforts to contain COVID-19. We set out to test whether decision aids can support self-isolation. DESIGN: We conducted a pre-registered online experiment with a nationally representative sample (n = 500). Three stages tested: (i) whether decision trees help people to decide whether they need to self-isolate; (ii) whether an online planning tool increases people's confidence in their ability to self-isolate; and (iii) whether infographics help people to absorb advice on managing a household in which someone must self-isolate. MAIN OUTCOME MEASURES: (i) Accuracy of matching symptom patterns to a response scale for the need to self-isolate; (ii) self-reported confidence in coping with self-isolation; (iii) objective tests of recall and comprehension. RESULTS: Decision trees improved decisions about when self-isolation was necessary, although participants systematically underestimated the need to self-isolate with less common COVID-19 symptoms (e.g. sore throat, fatigue). The online planning tool increased confidence about coping with self-isolation only among the adults aged under 40. Infographics improved recall and comprehension of how to manage self-isolation. CONCLUSION: Decision aids can be used to support self-isolation during COVID-19. The study also demonstrates how even an emergency public health response can benefit from rapid experimental pre-testing of interventions.

Motivating social distancing during the COVID-19 pandemic: An online experiment.

RATIONALE: Maintaining social distance during the COVID-19 pandemic can save lives. We therefore set out to test communication strategies to promote social distancing. OBJECTIVE: We aimed to test two novel public health messages against a control message. The first was designed to exploit the "identifiable victim" effect by highlighting the risk of transmission to identifiable vulnerable persons. The second sought to counteract intuitive underestimation of exponential transmission. METHOD: In total, 500 Irish adults undertook a pre-registered, online experiment. They were randomly assigned to a control group or one of two treatment groups. The control group viewed a current poster that encouraged a 2-m separation between people. The two treatment groups saw posters of similar design, but with narrative messages describing how an individual had infected a specific vulnerable person or multiple other people. Later questions measured intentions to undertake three specific types of social interaction over the coming days and the stated acceptability of three other types of social interaction. Pilot work had identified these six behaviors as "marginal" - people were unsure whether they were advisable. RESULTS: Participants in the treatment conditions were more cautious about undertaking the behaviors and less accepting of them. This positive effect occurred despite participants rating the treatment posters as likely to be less effective and memorable than the control poster. CONCLUSIONS: Messages that invoke thoughts of infecting vulnerable people or large numbers of people can motivate social distancing and, hence, help to limit the spread of COVID-19. Stated public evaluations (obtained via focus groups or surveys) may underestimate the actual effectiveness of such emotional messages.