This research adopted the Theory of Planned Behavior (TPB) to predict intention and behavior to avoid food waste. In a pilot study, behavioral, normative, and control beliefs were identified. In the main study, a TPB model extended with descriptive and moral norms was assessed using a two-wave design and applying SEM. The associations between beliefs and TPB constructs were analyzed by MIMIC models. Attitude, descriptive and moral norms, and perceived behavioral control were associated with intention to avoid food waste, which predicted behavior. Considering the most important beliefs in forming intentions has important implications for designing food waste prevention interventions.

Social norm interventions hold the potential to change people\'s behavior. Five field experiments (N = 1,163) examined the effects of a simple and easily realizable social norm nudge based on the social media format \"Be like Bill.\" The nudge consisted of a stick figure named Toni that communicated descriptive and injunctive norms regarding pro-environmental or pro-social behaviors. Nudge conditions were compared to no-intervention control conditions. Experiment 1 (N = 179) focused on paper towel consumption in a women\'s restroom at a German university. The nudge condition used less paper towels than the control condition, d = 0.48. Experiment 2 (N = 183) replicated this result (d = 0.32) in a more diverse setting of a women\'s restroom at a German Christmas market. Experiment 3 (N = 250) examined differences in the effects of prescriptive (i.e., \'do-norm\') versus proscriptive (i.e., \'do not-norm\') social norms on paper towel consumption again in a university women\'s restroom. The effectiveness of both social norm nudge conditions was shown in comparison to the control condition (d = 0.46; d = 0.40), while the prescriptive and proscriptive social norm manipulations did not differ. Experiment 4 (N = 206) applied the nudging approach to the use of plastic lids in a coffee shop, where no effect was found. Finally, Experiment 5 (N = 345) focused on the pro-social behavior of mask wearing in a bakery toward the end of the Covid-19 pandemic restrictions in Germany. In the nudge condition, more visitors put on face masks compared to the control group, d = 0.39. Limitations and contextual factors regarding the applicability of our social norm nudge are discussed.

A pro-environmental behavior (PEB) intervention may increase the adoption of other PEBs that were not targeted by the intervention, leading to a positive spillover effect. Communication that both support autonomy, as defined by self-determination theory, and compliance with descriptive norms may promote the targeted PEBs and positive spillover effect. Such communication may enhance autonomous motivation to adopt PEBs. A pilot study (N = 350) about waste management in a university campus found that autonomous communication supplemented by normative information influenced both targeted and non-targeted behavioral intentions, compared to autonomous-only and controlling communication. Findings were replicated in a main study (N = 629). An intervention combining autonomy support and descriptive norms increased the likelihood of a positive spillover effect in contrast to an intervention combining controlling communication and descriptive norms. In both studies, autonomous motivation mediated the positive spillover effect. Results suggest that communication that promotes autonomous motivation by fulfilling basic self-determination needs may have a broader effect on a wider range of PEBs.

The induced-hypocrisy is a paradigm in which people promote a normative behavior (normative salience step) and then recall their past transgressions (transgression salience step). It is an effective two-step procedure for encouraging prosocial behaviors. This study aims to explore whether discrimination can be reduced using the hypocrisy paradigm combining two kinds of social norms, namely injunctive and descriptive norms. We assigned 80 participants to descriptive norm-related hypocrisy, injunctive norm-related hypocrisy, combined-norm hypocrisy, and control conditions. Results showed that intention to adopt active normative behaviors was higher in the combined-norms than in the single norm hypocrisy conditions. We observed the same pattern in reducing discriminatory behaviors in the Cyberball game, which measures passive discrimination (exclusion). Our findings have both practical and theoretical implications. First, they provide a new and effective means for producing behavioral changes in the field of discrimination. Second, they contribute to further investigating the explanatory processes underlying the hypocrisy effect.

Research on health-related self-uniqueness beliefs suggested that these beliefs might predict adherence to precautions against COVID-19.
We examined if comparative optimism (believing that one is less at less than others), self-superiority (believing that one already adheres better to precautions than others), and egocentric impact perception (believing that adverse events affect oneself more than others) predicted intended adherence to precautions.
We measured self-reported intentions, optimism for self and others, perceived past adherence by self and others, and perceived impact of the measures and the disease on self and others in a 5-wave longitudinal study in December 2020-May 2021 (N ≈ 5000/wave). The sample was in key respects representative for the Belgian population. We used joint models to examine the relationship between self-uniqueness beliefs and intended adherence to the precautions.
Believing that COVID-19 would affect one\'s own life more than average (egocentric impact perception) was associated with higher intentions to adhere to precautions, as was believing that the precautions affected one\'s life less than average (allocentric impact perception). Self-superiority concerning past adherence to precautions and comparative optimism concerning infection with COVID-19 were associated with higher intended adherence, regardless of whether their non-comparative counterparts (descriptive norm, i.e., perceived adherence to precautions by others, and personal optimism, respectively) were controlled for. Comparative optimism for severe disease and for good outcome were associated with lower intended adherence if personal optimism was not controlled for, but with higher intended adherence if it was controlled for.
Self-uniqueness beliefs predict intended adherence to precautions against COVID-19, but do so in different directions.

Previous studies have found that social norms affect eating behavior for different types of social norm measures and manipulations as well as different types of eating behavior. The current study investigated the effects of descriptive, injunctive, and liking norms on intentions to consume healthy snacks and anticipated snack choice, compared to a no-norm control condition. Moreover, we distinguished between descriptive norms that stress the frequency versus the quantity of food consumption. An experiment was conducted among 189 young adults. It was hypothesized that participants who received a descriptive quantity or frequency norm would intend to consume, and make an anticipated selection of, more low-calorie snacks than participants who received a no-norm control message. Due to inconsistency or lacking evidence regarding the effects of the other types of norms on eating behavior, no hypotheses were formulated for the injunctive and liking norm conditions. The hypothesis was partly confirmed. Descriptive quantity and frequency norms did not result in a stronger intention to consume healthy snacks in the upcoming week, but they did result in lower-calorie snack choices when people were asked to select three snacks that they planned to eat on the following day. No other differences between the conditions were found. These findings show that emphasizing both how much and how often most other people consume healthy foods affects anticipated healthy food choices. This can provide health professionals more options to mobilize the power of descriptive social norms for affecting health behavior change.

Though health insurance policies remain critical to eliminating healthcare access barriers, population-wide subscription in Ghana however remains unsatisfactory. Therefore, this study, while employing a questionnaire survey to elicit data (n= 312) analyzed via the structural equation modeling technique, investigates individual health insurance subscription underpinnings using the theory of planned behavior. The results of data analysis affirmed attitude, subjective norm and perceived behavior control as positively related to health insurance subscription. Similarly, results further revealed personal norm and descriptive norm as significantly related to intention, testifying to individuals\' subscription as not anchored on a single factor, but rather on a confluence of behavior-driven elements. The current study, in addition to affirming the TPB\'s predictive potency, also enriches health insurance research, and underscores the much often-disregarded behavior constituents as imperative to health policy design and implementation. In view of the study results, implications for augmenting subscription, and suggestions for further research are subsequently delineated.

This study investigated the influence of descriptive norm messages that either communicated that university students eat a sufficient amount of fruit and vegetable (F&V) or that they do not, on F&V consumption, and whether or not any effects are moderated by student identification. An online 2 (Norm: \"Sufficient\"/\"Insufficient\") × 2 (Identification: \"Low\"/\"High\") experimental design was employed. Infographics containing \"sufficient\"/\"insufficient\" F&V intake descriptive norms were presented. An identification manipulation was employed to create \"high\"/\"low\" student identifiers. F&V intake intentions were assessed after the manipulations; self-reported F&V intake was reported at 2 days post-intervention. Undergraduate students in the United Kingdom (N = 180) reported their intake intentions, of which 112 (62%) completed the behavioral follow-up. Participants were predominantly white female students from Scottish universities, mean age 20.4 (±1.6) years. Baseline mean F&V consumption was high (4.5 ± 2.8). There were no significant main effects of Norm or Identification manipulations on F&V intentions and intake. Significant norm × identification interactions were revealed for fruit intake intentions and vegetable intake at follow-up, indicating half-portion differences (~40 g) between groups. Ironic effects were observed for \"high\" identifiers, who neither intended to, nor acted in accordance with group norms; \"low\" student identifiers intended to and followed group norms, whereby the \"sufficient\"/\"low\" group intended to consume significantly more fruit portions and consumed more vegetables than the \"insufficient\"/\"low\" group. Given the half-portion differences between groups resulting from the norm × identification interactions, future research on a larger sample of young adults with low F&V intake is warranted to further explore the conditions under which moderating effects of identification are observed and the underlying mechanisms.

Through meat-eating choices, people are able to express their national social identification and adhere to broader cultural norms. The current research examines the relationship between people\'s perceptions of national descriptive and injunctive meat-eating norms and their national social identification, on the one hand, and their attitudes toward meat-eating and their intentions to eat meat, on the other hand. In a sample that includes American, British, and Australian participants, we observe that: (1) favorable attitudes toward meat eating are positively predicted by national injunctive but not descriptive norms, and (2) intentions to eat meat are positively predicted by national descriptive but not injunctive norms. National social identification positively predicts both attitudes and intentions. Intentions to eat meat were also predicted by a three-way interaction between descriptive and injunctive norms, and social identification. Alignment of relatively high descriptive and injunctive meat-eating norms predicted meat-eating intentions more than alignment of relatively low descriptive and injunctive norms. With normative misalignment, however, people began to rely on their national social identifications as a basis for meat-eating intentions. The data are discussed with reference to the impact of social factors in influencing meat consumption. Moreover, we consider the potential for national social identification to have a normative component of meat consumption independent of descriptive and injunctive norms. This work advances our understanding of meat consumption by revealing national-level normative and identity processes beyond more focused identities of, for example, an environmentalist, a health conscious person, or an animal rights activist.

COVID-19 has caused a devastating impact on public health and made the development of the COVID-19 vaccination a top priority. Herd immunity through vaccination requires a sufficient number of the population to be vaccinated. Research on factors that promote intention to receive the COVID-19 vaccination is warranted. Based on Diffusion of Innovations Theory, this study examines the association between the perceived efficacy of the COVID-19 vaccination, use of social media for COVID-19 vaccine-related information, openness to experience and descriptive norm with the intention to receive the COVID-19 vaccination, and the moderating role of openness to experience among 6922 university students in mainland China. The intention to receive the free and self-paid COVID-19 vaccination is 78.9% and 60.2%, respectively. Results from path analyses show that perceived efficacy of the COVID-19 vaccination, use of social media for COVID-19 vaccine-related information, and openness to experience and descriptive norm are all positively associated with the intention to receive COVID-19 free and self-paid vaccination. The association between the perceived efficacy of the COVID-19 vaccination and descriptive norm with the intention to receive the COVID-19 vaccination is stronger among those with a lower level of openness to experience. Our findings support the usefulness of Diffusion of Innovations Theory and the moderating role of openness of experience in explaining intention to receive the COVID-19 vaccination.