How does nudging the COVID-19 vaccine play out in people who are in doubt about vaccination?

In spite of the growing availability of COVID-19 vaccines, a substantial number of people is reluctant or uncertain about getting the vaccine. Nudges may improve vaccine uptake but it is unclear how this plays out with the experience of autonomous choice, decision competence, decision satisfaction, and being pressured to make a choice. In an online experiment among a representative sample (N = 884), we examined whether a social norm nudge or a default nudge (either or not transparent) was effective in steering the desired choice of making a hypothetical early vaccination appointment as compared to making a later appointment or no appointment. We also examined how both nudges affected autonomy and related downstream consequences. None of the nudges proved effective in making the desired choice of early vaccination and neither did they impact on downstream consequences. Rather, our results indicate that participants who were certain about their choice (i.e., opted for the earliest available vaccination opportunity or not getting vaccinated at all) reported higher levels of autonomy, competence and satisfaction than participants who did not know yet about vaccination or who postponed the moment of getting their vaccination. We conclude that the experience of autonomy and related downstream consequences is determined by having made up one's mind about vaccination, and is not affected by attempts to nudge the individual.

Understanding public support for COVID-19 pandemic mitigation measures over time: Does it wear out?

Background COVID-19 mitigation measures intend to protect public health, but their adverse psychological, social, and economic effects weaken public support. Less favorable trade-offs may especially weaken support for more restrictive measures. Support for mitigation measures may also differ between population subgroups who experience different benefits and costs, and decrease over time, a phenomenon termed "pandemic fatigue.” Methods We examined self-reported support for COVID-19 mitigation measures in the Netherlands over 12 consecutives waves of data collection between April 2020 and May 2021 in an open population cohort study. Participants were recruited through community panels of the 25 regional public health services, and through links to the online surveys advertised on social media. The 54,010 unique participants in the cohort study on average participated in 4 waves of data collection. Most participants were female (65%), middle-aged [57% (40–69 years)], highly educated (57%), not living alone (84%), residing in an urban area (60%), and born in the Netherlands (95%). Results COVID-19 mitigation measures implemented in the Netherlands remained generally well-supported over time [all scores >3 on 5-point scale ranging 1 (low)−5 (high)]. During the whole period studied, support was highest for personal hygiene measures, quarantine and wearing face masks, high but somewhat lower for not shaking hands, testing and self-isolation, and restricting social contacts, and lowest for limiting visitors at home, and not traveling abroad. Women and higher educated people were more supportive of some mitigation measures than men and lower educated people. Older people were more supportive of more restrictive measures than younger people, and support for more socially restrictive measures decreased most over time in higher educated people or in younger people. Conclusions This study found no support for pandemic fatigue in terms of a gradual decline in support for all mitigation measures in the first year of the pandemic. Rather, findings suggest that support for mitigation measures reflects a balancing of benefits and cost, which may change over time, and differ between measures and population subgroups.

Understanding public support for COVID-19 pandemic mitigation measures over time: Does it wear out?

Background: COVID-19 mitigation measures intend to protect public health, but their adverse psychological, social, and economic effects weaken public support. Less favorable trade-offs may especially weaken support for more restrictive measures. Support for mitigation measures may also differ between population subgroups who experience different benefits and costs, and decrease over time, a phenomenon termed "pandemic fatigue." Methods: We examined self-reported support for COVID-19 mitigation measures in the Netherlands over 12 consecutives waves of data collection between April 2020 and May 2021 in an open population cohort study. Participants were recruited through community panels of the 25 regional public health services, and through links to the online surveys advertised on social media. The 54,010 unique participants in the cohort study on average participated in 4 waves of data collection. Most participants were female (65%), middle-aged [57% (40-69 years)], highly educated (57%), not living alone (84%), residing in an urban area (60%), and born in the Netherlands (95%). Results: COVID-19 mitigation measures implemented in the Netherlands remained generally well-supported over time [all scores >3 on 5-point scale ranging 1 (low)-5 (high)]. During the whole period studied, support was highest for personal hygiene measures, quarantine and wearing face masks, high but somewhat lower for not shaking hands, testing and self-isolation, and restricting social contacts, and lowest for limiting visitors at home, and not traveling abroad. Women and higher educated people were more supportive of some mitigation measures than men and lower educated people. Older people were more supportive of more restrictive measures than younger people, and support for more socially restrictive measures decreased most over time in higher educated people or in younger people. Conclusions: This study found no support for pandemic fatigue in terms of a gradual decline in support for all mitigation measures in the first year of the pandemic. Rather, findings suggest that support for mitigation measures reflects a balancing of benefits and cost, which may change over time, and differ between measures and population subgroups.

How do people understand the spread of COVID-19 infections? Mapping mental models of factors contributing to the pandemic.

OBJECTIVE: To describe the mental models people hold about the COVID-19 pandemic, with a focus on how they understand the factors that drive the spread of COVID-19 and what kind of beliefs are associated with these models. DESIGN: In a series of three studies (total N = 461), we asked participants to identify factors that are relevant for COVID-19 proliferation (Study 1a), rate the importance of factors (Study 1 b), and create a mental model of how these factors relate to virus spread by employing a validated tool for mental model elicitation (Study 2). Main outcome measures: inclusion and centrality of factors in mental models of COVID-19 infection spread. RESULTS: Mitigation measures issued by government, adherence to measures, and virus characteristics were most strongly represented in participants' mental models. Participants who perceived measures as appropriate or who experienced more control and more worry over the spread of the virus created more complex models compared to participants who were less satisfied with measures or who felt lower control and less worry. CONCLUSION: These findings suggest that people are able to create sensible mental models of virus transmission but may appreciate transparent communication to comprehend the bigger picture behind the governmental mitigation strategy.

Make it a habit: how habit strength, goal importance and self-control predict hand washing behaviour over time during the COVID-19 pandemic.

OBJECTIVE: Hand washing has been at the core of recommendations and guidelines that aim to curb infectious diseases in general, and COVID-19 in particular. As hand washing comes down to an individual's behaviour, we aimed to study how individual psychological variables influence hand washing over time during the COVID-19 pandemic. DESIGN: Over the course of 20 weeks, participants answered questions about their hand washing behaviour, goal importance, habit strength and self-control. Participants from an experimental and a control condition completed a baseline and final measurement, and the experimental condition was invited to bi-weekly measurements through reminders. MAIN OUTCOME MEASURE: Hand washing behaviour over the past 14 days was assessed by self-report at baseline and final measurement, and additionally repeatedly over the course of 20 weeks in the experimental condition. RESULTS: Hand washing behaviour decreased over time, but this decrease was buffered by habit strength and goal importance. The decrease was smaller in the experimental condition that received reminders every 2 weeks. CONCLUSION: Sending personal reminders on hand washing behaviour contributes to hand washing behaviour. Moreover, taking habit strength and goal importance, and to a lesser extent self-control into account is important when designing interventions to promote hand washing behaviour.

"Keep your distance for me": A field experiment on empathy prompts to promote distancing during the COVID-19 pandemic.

The outbreak of COVID-19 has turned out to be a major challenge to societies all over the globe. Curbing the pandemic requires rapid and extensive behavioural change to limit social interaction, including physical distancing. In this study, we tested the notion that inducing empathy for people vulnerable to the virus may result in actual distancing behaviour beyond the mere motivation to do so. In a large field experiment with a sequential case-control design, we found that (a) empathy prompts may increase distancing as assessed by camera recordings and (b) effectiveness of prompts depends on the dynamics of the pandemic and associated public health policies. In sum, the present study demonstrates the potential of empathy-generating interventions to promote pro-social behaviour and emphasizes the necessity of field experiments to assess the role of context before advising policy makers to implement measures derived from behavioural science. Please refer to Supplementary Material to find this article's Community and Social Impact Statement.

Eating behavior and food purchases during the COVID-19 lockdown: A cross-sectional study among adults in the Netherlands.

On March 15, 2020, the Dutch Government implemented COVID-19 lockdown measures. Although self-quarantine and social-distancing measures were implemented, restrictions were less severe compared to several other countries. The aim of this study was to assess changes in eating behavior and food purchases among a representative adult sample in the Netherlands (n = 1030), five weeks into lockdown. The results show that most participants did not change their eating behaviors (83.0%) or food purchases (73.3%). However, socio-demographic differences were observed among those that reported changes during lockdown. For example, participants with overweight (OR = 2.26, 95%CI = 1.24-4.11) and obesity (OR = 4.21, 95%CI = 2.13-8.32) were more likely to indicate to eat unhealthier during lockdown compared to participants with a healthy weight. Those with a high educational level (OR = 2.25, 95%-CI = 1.03-4.93) were also more likely to indicate to eat unhealthier during lockdown compared to those with a low educational level. Older participants were more likely to indicate to experience no differences in their eating behaviors compared to those of younger age, who were more likely to indicate that they ate healthier (OR = 1.03, 95%CI = 1.01-1.04) as well as unhealthier (OR = 1.04, 95%CI = 1.02-1.06) during lockdown. Participants with obesity were more likely to indicate to purchase more chips/snacks (OR = 2.79, 95%CI = 1.43-5.45) and more nonalcoholic beverages (OR = 2.74, 95%CI = 1.36-5.50) during lockdown in comparison with those with a healthy weight. Of those that used meal delivery services before, 174 (29.5%) indicated to use meal delivery services more frequently during lockdown. Although the results confirm the persistence of dietary routines, profound socio-demographic differences were observed for those that did report changes. Especially for individuals with overweight and obesity, the lockdown has taken its toll on healthy dietary choices. Further research should unravel underlying mechanisms for these observations.