Oogkleppen af!: Gedragsverandering voor een gezonde wetenschap en samenleving

Oratie uitgesproken door Prof. Dr. Marieke Adriaanse bij de aanvaarding van het ambt van Hoogleraar Gedragsinterventies in Populatiegerichte Zorg aan de Universiteit Leiden op vrijdag 2 december 2022Oratie uitgesproken door Prof. Dr. Marieke Adriaanse bij de aanvaarding van het ambt van Hoogleraar Gedragsinterventies in Populatiegerichte Zorg aan de Universiteit Leiden op vrijdag 2 december 2022LUMC / Geneeskund

Beyond prevention: regulating responses to self-regulation failure to avoid a set-back effect

Despite having good intentions, people fail at times to self-regulate. Most of these instances of everyday self-regulation failure are in themselves trivial. However, the ensuing chain of attributions, thoughts, and subsequent behaviors that people experience after an instance of failure may be detrimental to their long-term self-regulation success. In two studies, we examined the potential of intervening in the aftermath of failure to prevent this so-called "setback effect" by instructing people that setbacks may occur and to attribute future incidents of failure to external causes. In Study 1, we tested whether the intervention indeed decreased the frequency of self-regulation failure in the context of dieting and procrastination. In Study 2, we aimed to replicate the findings from Study 1 in the context of procrastination, and we explored the mediating role of self-efficacy. In both studies, participants in the intervention condition experienced less self-regulation failure and more subjective self-regulation success in the days after the intervention. Study 2 demonstrated that this effect was partly mediated by an increase in self-efficacy. Taken together, findings suggest that a simple mindset manipulation promoting external attributions to failure may be effective in preventing a setback effect from occurring by protecting self-efficacy.Prevention, Population and Disease management (PrePoD)Public Health and primary car

The influence of nudge transparency on the experience of autonomy

While nudges have been shown to be effective and are already being implemented, there is still a debate on the ethics of nudging. This debate specifically refers to the potential of nudges negatively affecting autonomy. It has been suggested that making a nudge transparent may resolve this issue. Whereas previous research has already demonstrated that transparency does not violate nudge effectiveness, it is unknown how transparency affects autonomy and related decision satisfaction and experienced pressure. In an online study with 905 participants, we investigated whether two variations of transparency influence the decision maker’s experience of autonomy, as well as their choice satisfaction and the experienced pressure to choose the nudged option. The results show that autonomy and satisfaction were high–and pressure low–across all conditions, and were therefore not influenced by transparency. Suggesting that nudges do not negatively affect autonomy and that transparency does also not increase it

The effect of nudges on autonomy in hypothetical and real life settings

Nudges have repeatedly been found to be effective, however they are claimed to harm autonomy, and it has been found that laypeople expect this too. To test whether these expectations translate to actual harm to experienced autonomy, three online studies were conducted. The paradigm used in all studies was that participants were asked to voluntarily participate in a longer version of the questionnaire. This was either done in a hypothetical setting, where participants imagined they were asked this question, but did not answer it, and reported their expectations for autonomy; Or in an actual choice setting where participants answered the question and then reported their actual autonomy. The first study utilized the hypothetical setting and tried to replicate that laypeople expect nudges to harm autonomy with the current paradigm. A total of 451 participants were randomly assigned to either a control, a default nudge, or a social norm nudge condition. In the default nudge condition, the affirmative answer was pre-selected, and in the social norm nudge condition it was stated that most people answered affirmative. The results showed a trend for lower expected autonomy in nudge conditions, but did not find significant evidence. In Study 2, with a sample size of 454, the same design was used in an actual choice setting. Only the default nudge was found to be effective, and no difference in autonomy was found. In Study 3, Studies 1 and 2 were replicated. Explanation of the nudge was added as an independent variable and the social norm nudge condition was dropped, resulting in six conditions and 1322 participants. The results showed that participants indeed expected default nudges to harm their autonomy, but only if the nudge was explained. When actually nudged, no effect on autonomy was found, independent of the presence of an explanation.Public Health and primary carePrevention, Population and Disease management (PrePoD

The effect of nudges on autonomy in hypothetical and real life settings

Nudges have repeatedly been found to be effective, however they are claimed to harm autonomy, and it has been found that laypeople expect this too. To test whether these expectations translate to actual harm to experienced autonomy, three online studies were conducted. The paradigm used in all studies was that participants were asked to voluntarily participate in a longer version of the questionnaire. This was either done in a hypothetical setting, where participants imagined they were asked this question, but did not answer it, and reported their expectations for autonomy; Or in an actual choice setting where participants answered the question and then reported their actual autonomy. The first study utilized the hypothetical setting and tried to replicate that laypeople expect nudges to harm autonomy with the current paradigm. A total of 451 participants were randomly assigned to either a control, a default nudge, or a social norm nudge condition. In the default nudge condition, the affirmative answer was pre-selected, and in the social norm nudge condition it was stated that most people answered affirmative. The results showed a trend for lower expected autonomy in nudge conditions, but did not find significant evidence. In Study 2, with a sample size of 454, the same design was used in an actual choice setting. Only the default nudge was found to be effective, and no difference in autonomy was found. In Study 3, Studies 1 and 2 were replicated. Explanation of the nudge was added as an independent variable and the social norm nudge condition was dropped, resulting in six conditions and 1322 participants. The results showed that participants indeed expected default nudges to harm their autonomy, but only if the nudge was explained. When actually nudged, no effect on autonomy was found, independent of the presence of an explanation

Motivated by default - how nudges facilitate people to act in line with their motivation

Nudges are defined as small adjustments in the choice architecture that help people perform desirable behavior. How nudges interact with individuals' motivation has not been studied empirically. We conducted three studies with different types of defaults in three different behavioral domains and investigated how defaults and different types of motivation affect choice outcomes. In Study 1, we investigated the effectiveness of a default to stimulate healthy eating choices implemented in a hypothetical online supermarket setting. In Study 2, we used a scenario in which participants could choose from a list of green amenities (either preselected or not). In Study 3, we asked participants whether they wanted to participate in a basic or longer version of our questionnaire, with the longer version option set as the default in the nudge condition. Across these three studies we show that defaults are effective in promoting desirable behavior and that goal strivings and autonomous motivation have additional positive main effects. We did not find evidence that controlled motivation affected behavioral outcomes. Exploratory analyses revealed that amotivation negatively affected behavior, but the measure had poor reliability. No significant interaction effects were observed. Together, these studies imply that both defaults and motivation have main effects on behavior, such that the default sets the anchor from which people can adjust according to the type and strength of their motivation. Implications for the practice and ethics of nudging are discussed.Public Health and primary carePrevention, Population and Disease management (PrePoD

The effects of nudges: one-shot only?: Exploring the temporal spillover effects of a default nudge

Nudges, such as defaults, are generally found to be effective in guiding immediate behavioural decisions. However, little is known about whether the effect of a nudge can be lasting, meaning that it spills over to subsequent similar choices without the presence of a nudge. In three experiments, we explored the temporal spillover effects of a default nudge. The results of Experiments 1 (N = 1,077) and 2 (N = 1,036) suggest that nudging participants into completing a longer questionnaire affected their decision for the same behaviour a day later without the presence of a nudge. However, nudging participants into a healthier food choice in Experiment 3 (N = 969) did not result in such a temporal spillover effect. The results indicated that participants' change in attitude towards the nudged behaviour may partly explain the temporal spillover effects. These findings suggest that for some, but not all behaviours, default nudges may have the potential to yield temporal spillover effects and warrant a further investigation of boundary conditions and facilitators of the spillover effects of nudges.Prevention, Population and Disease management (PrePoD)Public Health and primary car

Do nudges make use of automatic processing? Unraveling the effects of a default nudge under type 1 and type 2 processing

Nudges have become increasingly popular among policymakers as a tool to stimulate desirable behavior for individuals or society. One of the most prevailing assumptions of nudges is that they make use of automatic processing. Yet, this assumption has received little attention in experimental research. In two preregistered and high powered studies, we investigated this hypothesized working mechanism by using a nudge that has most typically been described as a Type 1nudge: defaults. In both studies, we used a scenario in which participants could choose from a list of green amenities, which were either preselected (opt-out condition) or not (opt-in condition). In Study 1, we investigated the effectiveness of this default nudge under Type 1 processing by manipulating cognitive load. In Study 2, we investigated its effectiveness under Type 2 processing by explicitly instructing half of the participants to deliberate upon their choice. Both studies revealed strong and robust evidence for the default effect. Study 1 further revealed that this default effect was statistically equivalent under cognitive load. Study 2 revealed that the default effect was not attenuated when participants deliberated upon their decision, but instead showed a main effect of deliberation. Together, this implies that default nudges are not dependent on elaborate processing in order to be effective, but that deliberation can in parallel lead to different choice outcomes

When nudgees become nudgers: exploring the use of self-nudging to promote fruit intake

The current study explored (1) the immediate and prolonged effects of self-nudges promoting fruit intake in the home environment, (2) whether the effect of self-nudges on fruit intake persists after self-nudges are no longer used (i.e. a temporal spillover effect) and (3) whether self-nudges can install healthy eating habits that, in turn, explain the temporal spillover effect. Participants (N = 331) were randomly assigned to either a control or self-nudge condition in which they had to choose a self-nudge promoting fruit consumption for 8 weeks. Thereafter, participants were asked to remove the self-nudge for 1 week to assess a possible temporal spillover effect. Results showed a positive effect of the self-nudges on fruit consumption right after implementation that continued during the 8 weeks in which the self-nudge was implemented, which was accompanied by an increase in fruit intake habit strength. However, a mixed picture emerged regarding the temporal spillover effect and no support was found for a mediation effect of habit strength. Although this study is only a first exploration of self-nudging to increase healthy food consumption, results indicate that self-nudging may be a promising extension of traditional nudging that can influence behaviour beyond out-of-home settings.Prevention, Population and Disease management (PrePoD

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