We meat again: a field study on the moderating role of location-specific consumer preferences in nudging vegetarian options.

This field study set out to test whether consumers' history of making decisions in a particular choice context moderated the effectiveness of a nudge intervention to reduce meat consumption. In a Danish hospital canteen that served both staff members and visitors, a combination of nudges (Chef's recommendation sticker + prominent positioning) was implemented to promote vegetarian sandwiches. The sales of these sandwiches increased from 16.45% during the baseline period to 25.16% during the nudge intervention period. Most notably, this increase was caused by the visitors, who had weak location-bound preferences. Hospital staff members (who had strong location-bound preferences) were unaffected by the nudge in their choice. This is an important finding because the two consumer groups did not differ on their person-bound preferences for meat. It seems that behaviour change is best predicted by location-bound preferences, whereas the behaviour itself is best predicted by person-bound preferences. These findings can help organizations in estimating whether a nudge intervention has enough potential for behaviour change, or whether more directive policies are required.

Changes in virus-transmission habits during the COVID-19 pandemic: a cross-national, repeated measures study.

OBJECTIVE: The COVID-19 pandemic saw promotion of novel virus transmission-reduction behaviours, and discouragement of familiar transmission-conducive behaviours. Understanding changes in the automatic nature of such behaviours is important, because habitual behaviours may be more easily reactivated in future outbreaks and disrupting old habits may discontinue unwanted behaviours. DESIGN: A repeated-measures, multi-national design tracked virus-transmission habits and behaviour fortnightly over six months (Apr-Sept 2020) among 517 participants (age M = 42 ± 16y, 79% female). MAIN OUTCOME MEASURES: Within-participant habit trajectories across all timepoints, and engagement in transmission-reduction behaviours (handwashing when entering home; handwashing with soap for 20 seconds; physical distancing) and transmission-conducive behaviours (coughing/sneezing into hands; making physical contact) summed over the final two timepoints. RESULTS: Three habit trajectory types were observed. Habits that remained strong ('stable strong habit') and habits that strengthened ('habit formation') were most common for transmission-reduction behaviours. Erosion of initially strong habits ('habit degradation') was most common for transmission-conducive behaviours. Regression analyses showed 'habit formation' and 'stable strong habit' trajectories were associated with greater behavioural engagement at later timepoints. CONCLUSION: Participants typically maintained or formed transmission-reduction habits, which encouraged later performance, and degraded transmission-conducive habits, which decreased performance. Findings suggest COVID-19-preventive habits may be recoverable in future virus outbreaks.

Perceived susceptibility to COVID-19 infection and narcissistic traits.

People's perceived susceptibility to illnesses plays a key role in determining whether or not to take protective measures. However, self-enhancing biases hinder accurate susceptibility perceptions, leaving some individuals to feel invulnerable in the face of acute health risks. Since such biases are prominent characteristics of individuals with narcissistic personality traits, this article empirically examined whether low perceived susceptibility of infection with COVID-19 is related to subclinical narcissism, as measured with the Narcissistic Personality Inventory (NPI-16) and the Narcissism Admiration and Rivalry Questionnaire (NARQ). We report the findings from a worldwide sample (N = 244), a UK sample before governmental pandemic restrictions (N = 261), a UK sample after restrictions (N = 261) and a pooled data analysis (N = 766). Overall, grandiose narcissism as measured with the NPI-16 predicted lower perceived susceptibility of infection, also after controlling for age and gender, whereas the NARQ Admiration subscale predicted higher perceived susceptibility. The findings are discussed in the light of theoretical and policy implications.

When in Doubt, Follow the Crowd? Responsiveness to Social Proof Nudges in the Absence of Clear Preferences.

Nudges have gained popularity as a behavioral change tool that aims to facilitate the selection of the sensible choice option by altering the way choice options are presented. Although nudges are designed to facilitate these choices without interfering with people's prior preferences, both the relation between individuals' prior preferences and nudge effectiveness, as well as the notion that nudges 'facilitate' decision-making have received little empirical scrutiny. Two studies examine the hypothesis that a social proof nudge is particularly effective when people have no clear prior preference, either because people are indifferent (in a color-categorization task; Study 1, N = 255) or because people experience a choice conflict (making shopping decisions about meat products; Study 2, N = 97). Both studies employed a social proof nudge to steer participants' choices. The potential facilitating effect of the nudge was tested using a mouse-tracker paradigm that implicitly assessed experienced uncertainty during decision-making. Results showed that the nudge was effective in steering participants' decisions; the facilitation effect (i.e., reduced uncertainty regarding the decision) was only observed for conflicting preferences, but not under indifference. A better understanding of when and how nudges can influence individuals' behavior may help in deciding whether nudges are an appropriate policy tool for changing particular undesirable behavior.

The (bitter) sweet taste of nudge effectiveness: The role of habits in a portion size nudge, a proof of concept study.

Seemingly insignificant daily practices, such as sugar usage in tea, can have a great accumulated impact on societal issues, such as obesity. That is why these behaviours are often the target of nudge interventions. However, when these behaviours are performed frequently they may turn into habits that are difficult to change. The aim of the current study was to investigate whether a portion size nudge has the potential to work in accordance with (instead of against) existing habits. Specifically, it was tested whether a portion size nudge would be more effective in reducing the amount of sugar added to tea, when people have a strong habit of adding a fixed amount of teaspoons of sugar to a cup of tea. The study (N = 123) had a mixed factorial design with teaspoon size (reduced size vs. control) as a within-subject factor, and habit disruption context condition (hot tea vs. cold tea) as a between-subjects factor. A paired t-test indicated that this nudge reduced sugar intake on average by 27% within subjects. When the context allowed for automatic enactment of the habit, the effectiveness of this nudge was moderated by habit strength. Surprisingly, the nudge effect was actually less pronounced when people had a strong habit. Implications for effective nudge interventions are discussed.

I'm still standing: A longitudinal study on the effect of a default nudge.

OBJECTIVE: This study assessed the effect of a default nudge to reduce sedentary behaviour at work over time. DESIGN AND MAIN OUTCOME MEASURES: A field study was conducted at a governmental organisation. In the present study, the default setting of sit-stand desks (SSDs) was changed from sitting to standing height during a two-week intervention. Stand-up working rates were calculated based on observations that were done prior to, during, two weeks after and two months after the intervention. Additionally, a pre-measure survey (n = 606) and post-measure survey (n = 354) were completed. Intention and social norms concerning stand-up working were compared for the 183 employees who completed both pre- and post-assessments (45.4% female, Mage = 44.21). RESULTS: Stand-up working rates raised from 1.82% in the baseline to 13.13% during the intervention. After the nudge was removed the percentage was 10.01% after two weeks and 7.78% after two months. A multilevel analysis indicated a significant increase in both intention and social norms after the nudge intervention. CONCLUSIONS: This study shows that a default nudge can increase stand-up working rates in offices with SSDs at least until two months after the nudge intervention.