The relationship between social identity, descriptive social norms and eating intentions and behaviors

I'll have what She's having (but not what They're having): The moderating role of group membership in the effect of social norms on food choice in an online environment

The modern food-rich environment has contributed to the rise of unhealthy diets linked to noncommunicable diseases. Previous in-person research has found that the effect of social norms on food intake is greater when set by a perceived in-group member relative to an out-group member. Given recent increased social media use, we investigated whether this effect of group membership extends to food choices and to normative information presented remotely online. Participants (N = 179 female university students, 18-32 years) viewed a Facebook page pertaining to either their university (in-group) or a rival university (out-group). They were presented with either a healthy or an unhealthy norm via a post in which a student discussed their order at a café on the relevant campus. Food choice was assessed through an online menu where participants were asked to order one main, side, and dessert dish. As predicted, participants who viewed the healthy norm ordered a higher percentage of healthy items (especially in the desserts category) relative to those who viewed the unhealthy norm. However, this effect was significant only for those in the in-group condition; there was no such pattern for participants in the out-group condition. These findings provide insight into the role of group membership in the effect of social norms, and have practical implications regarding the design of identity-based social media health campaigns to promote healthier eating behaviours.

Higher Numbers of Family Meals and Social Eating Behavior Are Associated with Greater Self-Esteem among Adolescents: The EHDLA

BACKGROUND

the aim of this study was to assess the associations of family meals and social eating behavior with self-esteem levels among Spanish adolescents.

METHODS

This was a secondary cross-sectional study including 706 participants (aged 12 to 17 years; 56.1% girls) from the Eating Habits and Daily Life Activities (EHDLA) study. The evaluation of the frequency of family meals involved participants providing information in physical education classes on how frequently they, along with other members of their household, had shared meals in the previous week. Social eating behavior was assessed by three different statements: "I usually have dinner with others", "Having at least one meal a day with others (family or friends) is important to me", and "I enjoy sitting down with family or friends for a meal". To assess overall self-esteem, the Rosenberg Self-Esteem Scale was used.

RESULTS

In the adjusted models, a positive association was observed between the frequency of family meals and the self-esteem score (unstandardized beta coefficient [B] = 0.06, 95% confidence interval [CI] 0.003 to 0.12, p-adjusted = 0.040). Furthermore, the same positive association was also identified between social eating behavior and the self-esteem score (B = 0.23; 95% CI 0.07 to 0.40, p-adjusted = 0.005).

CONCLUSIONS

Although self-esteem is complex and can be influenced by numerous factors, both family meals and social eating behavior may exert a relevant role in adolescents. Encouraging consistent participation in family meals and promoting positive eating practices could be valuable approaches in public health actions targeting the enhancement of self-esteem levels in adolescents.

Does social-norm messaging influence expected satiety and ideal portion-size selection?

A person's perception of how long a food will stave off hunger (expected satiety) and the ideal amount to consume (ideal portion size) are both influenced by food-to-mealtime norms. Here, we examine whether social norms can modulate this effect, in three experimental studies. In study 1 (n = 235) participants were exposed to a social norm suggesting most people enjoyed consuming pasta for breakfast. There was a main effect of food-to-mealtime congruence for expected satiety and ideal portion size (p < 0.001) - participants selected a smaller portion of pasta for breakfast (vs. lunch) - but there were no other main effects/interactions (p ≥ 0.15). Study 2 (n = 200) followed the same approach as study 1, but sought to examine whether the typical volume of food consumed at breakfast and lunch needed to be controlled. Again, there was a main effect of congruence (the same pattern) (p ≤ 0.02) but no other main effects/interactions (p ≥ 0.73). Study 3 (n = 208) followed the same approach as study 2, but the social-norm message was changed to suggest that most people who eat pasta for breakfast found it effectively reduced their hunger. Again, there was a main effect of congruence (the same pattern) (p < 0.001) but no other main effects/interaction (p ≥ 0.26). These studies provide further evidence for the food-to-mealtime effect, but do not provide any evidence that a single, simple social-norm statement can modulate expected satiety or ideal portion size, or interact with the food-to-mealtime effect.

Can social media be used to increase fruit and vegetable consumption? A pilot intervention study

Background

Exposure to social norms about fruit and vegetable intake has been shown to increase individuals' consumption of these foods. Further, exposure to socially endorsed 'healthy' food posts can increase consumption of low energy-dense (LED), relative to high energy-dense (HED) foods. The current pilot study aimed to investigate whether exposure to healthy eating (vs. control) social media accounts can shift normative perceptions about what others eat, eating intentions and self-reported food consumption.

Methods

In a 2 (condition) × 2 (type of food consumed) mixed factorial design, 52 male and female students were asked to follow either healthy eating (intervention) or interior design (control) Instagram accounts over a two-week period. Baseline and post-intervention measures assessed normative perceptions of Instagram users' consumption of fruit and vegetables (LED foods), and energy dense snacks and sugar sweetened beverages (HED foods). Participants' intentions to consume, and self-reported consumption of these foods, were also measured.

Results

There were no significant changes in perceptions about what others eat, or participants' own eating intentions (ps > 0.05). However, the intervention increased participants' self-reported consumption of LED foods by 1.37 servings (per day) and decreased consumption of HED foods by 0.81 items (per day), compared to the control condition (ps < 0.05).

Conclusions

This novel pilot study demonstrates that a social norm-based social media intervention can successfully encourage healthier eating, with a large effect after two weeks. Certain social media platforms may therefore provide a viable tool for nudging healthy eating. Future work will aim to replicate these findings in a larger and more diverse sample.

Will attitudes corrected by social norms have a more powerful impact on pro-environmental behavior? Evidence from a process model moderated by self-construal

Residents' pro-environmental behaviors are considered important for reducing carbon emissions and achieving carbon neutrality. However, optimizing the implementation of pro-environmental behavior need to be further studied. To this end, we placed residents' recycling behavior within a socialized situation. Explored the "Attitude-Behavior intention-Behavior" intermediary path regulated by self-construal, whether and how it can more effectively promote residents to transfer recycling behavior intention as recycling behavior after joining the influence of social norms. The results showed that after considering the influence of social norms, the transformation of residents' Habit adjustment recycling behavior (HAB) was significantly improved. Further, the masking effect of "Behavioral intention-Interpersonal facilitation recycling behavior (IFB)" in the mediation model was effectively reduced. HAB and IFB had stronger dependence on independent self-construal (IDSC) and interdependent self-construal (ITSC), respectively. In addition, when the self-construal level was low, the overall effect of the chain mediation model was stronger, highlighting the advantage of the role played by social norms.

Body dissatisfaction, ideals, and identity in the development of disordered eating among adolescent ballet dancers

OBJECTIVE

Little is known about how female adolescent ballet dancers-a group at high-risk for the development of body dissatisfaction and eating disorders-construct body ideals, and how their social identities interact with body ideals to confer risk for disordered eating. Using a novel body figure behavioral task, this study investigated (1) whether degree of body dissatisfaction corresponded to severity of disordered eating thoughts and behaviors, and (2) how ballet identity corresponded with ideal body figure size among adolescent ballet dancers.

METHODS

Participants were 188 female ballet dancers ages 13-18 years who completed self-report measures of study constructs and the behavioral task.

RESULTS

Linear regression models indicated that more severe body dissatisfaction was positively associated with increased disordered eating thoughts and behaviors (p < .19), except for muscle building (p = .32). We also found that identifying more strongly as a ballet dancer was correlated with having a smaller ideal body size (p = .017).

CONCLUSION

Findings from this study suggest desire to achieve smaller body sizes is correlated with more severe disordered eating endorsement and stronger ballet identity. Instructors and clinicians may consider assessing the extent to which individuals identify as a ballet dancer as a risk factor for disordered eating and encourage adolescent dancers to build and nurture other identities beyond ballet.

PUBLIC SIGNIFICANCE

Eating disorders are debilitating conditions that can lead to malnutrition, social isolation, and even premature death. Though disordered eating thoughts and behaviors can affect anyone, adolescents in physically demanding and body image-driven activities including ballet dance are particularly vulnerable. Investigating how factors like body dissatisfaction and strength of identity are associated with disordered eating among high-risk groups is crucial for developing effective prevention and intervention methods that minimize harm.

Information, ingestion, and impulsivity: The impact of technology-enabled healthy food labels on online grocery shopping in impulsive and non-impulsive consumers

Introduction

Unhealthy food consumption is a problem for society, companies, and consumers. This study aims to contribute to knowledge regarding such issues by investigating how technology-enabled healthy food labels can impact food choice in an online grocery store context. We conceptualized unhealthy and healthy food choice as a matter of impulsivity problems. Three technology-enabled healthy food labels were derived based on variables that might impact self-control, and their influence on food choice was investigated.

Methods

The empirical study consisted of three parts. In the first part, participants’ impulsivity was measured using an adjusting delay task. Part two investigated the effects of self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels on food choice in a hypothetical online grocery shopping setting using a choice-based conjoint experiment. Lastly, in the third part, three where demographical questions were asked.

Results

The results (n = 405) show that self-monitoring, pre-commitment, and social comparison-based technology-enabled healthy food labels had the most to least impact on food choice in that order. Furthermore, the results indicate that self-monitoring and pre-commitment labels had more impact on the choice for impulsive compared to non-impulsive participants. Similarly, the results indicate that social comparison had more impact on choice for non-impulsive participants. These findings suggest that self-monitoring of previous healthy food choices might be more effective than pre-commitment based on discounts for healthy food products. However, these differences were minor.

Discussion

This finding has managerial implications as grocery stores might increase their revenue by introducing self-monitoring labels in an online grocery shopping setting. Future research should investigate these technology-enabled healthy food labels in natural food purchase settings.

The reciprocal relationship between social identity and adherence to group norms

Previous research has focused on how social identification influences people's adherence to group norms, but has rarely considered how norm adherence might in turn influence how strongly people identify with the group. We proposed a reciprocal relationship between social identification and norm adherence that is shaped by the salience of the social identity in question. Drawing on data from a longitudinal field study of young people attending a mass gathering (N = 661, 1239 unique observations), we used cross-lagged panel modelling across five timepoints to test the reciprocal relationship between social identification with friends and anticipated adherence to perceived drinking norms among friends before (T0), during (T1-T3), and after (T4) the event. Greater social identification at T1 significantly predicted greater norm adherence at T2 which, in turn, predicted greater social identification at T3. These bidirectional effects were only significant during the mass gathering event, when the referent social identity was salient and thus relevant and meaningful in the social context. Findings indicate a complex interplay between social identity and norm adherence that is context dependent and evolves over time. Not only does social identity promote norm adherence but also adherence to those same norms can reinforce a sense of connection to the group.

Psychological Pathways Through Which Social Norms and Social Identity Influence Eating Behavior: Testing a Conceptual Model

BACKGROUND

Although interventions frequently promote healthy eating, failing to consider psychosocial factors, such as social norms, may limit the effectiveness of these efforts. Perceived social norms are a well-documented determinant of eating behavior; however, there is limited understanding of the processes through which, and for whom, this relationship emerges. Using identity-based motivation as a theoretical framework, we present a conceptual model identifying one route through which descriptive social norms-beliefs about how others behave-predict eating behavior, and test whether this process varies across social identities (e.g., self-perceived weight status).

METHOD

Structured telephone interviews were conducted for a national sample of non-diabetic adults who identified as non-Hispanic White, non-Hispanic Black, or Mexican American (n = 990).

RESULTS

Multigroup SEM analysis comparing individuals who self-identified as overweight (versus "about the right weight" and underweight) demonstrated that perceiving descriptive social norms that people do not eat healthy foods predicted greater perceived barriers to eating healthy foods. Perceived barriers, in turn, predicted stronger beliefs that body weight is uncontrollable, and this relationship was stronger for participants who self-identified as overweight (relative to participants who did not identify as overweight). These beliefs subsequently predicted greater self-reported consumption of unhealthy foods (e.g., sweets), but did not predict consumption of fruits or vegetables.

CONCLUSIONS

This study extends our understanding of a psychosocial process that predicts consumption of unhealthy foods and underscores the importance of social identities for shaping responses to perceived norms.

The influence of social norms on anticipated snacking: An experimental study comparing different types of social norms

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.

Follow or not? Descriptive norms and public health compliance: Mediating role of risk perception and moderating effect of behavioral visibility

In a pandemic context, public health events are receiving unprecedented attention, and identifying ways to enhance individual public health compliance behaviors has become an urgent practical problem. Considering that individual decisions are susceptible to group members' behaviors and that descriptive norms provide social information about the typical behaviors of others, we focused on the effects of the properties and reference groups of descriptive norms on public health compliance behaviors. We also investigated the mechanism with risk perception as a mediator and the applicable condition with behavioral visibility as a moderator. Through a 2 × 2 × 2 between-subject survey experiment with 529 subjects, we demonstrated that (1) compared with the negative norm, the positive norm was more effective in promoting public health compliance behaviors; (2) compared with the distal group norm, the proximal group norm more significantly promoted public health compliance behaviors; (3) the effect of the property of descriptive norms on public health compliance behaviors was weakened in the treatment of the proximal group norm; (4) risk perception partially mediated the association between the property of descriptive norms and public health compliance behaviors and fully mediated the effect of the interaction of the property and the reference group of descriptive norms on public health compliance behaviors; in the treatment of the negative-proximal group norm, individuals perceived more risk, thus effectively nudging their public health compliance behaviors; (5) compared with low-visibility behaviors, public health compliance behaviors were significantly stronger for high-visibility behaviors; (6) the property of descriptive norms had a weaker effect on public health compliance behaviors for low-visibility behaviors. In terms of theoretical significance, we refined the study of descriptive norms to promote the application of behavioral public policy. Moreover, the new model of public health compliance behaviors constructed in this study explains the mechanism and applicable conditions of public health compliance behaviors. In practical terms, this study has implications for designing intervention programs to nudge public health compliance behaviors.

Perceptions of social norms around healthy and environmentally-friendly food choices: Linking the role of referent groups to behavior

Referent groups can moderate the perception of social norms and individuals' likelihood to model these norms in food choice contexts, including vegetable intake and reduced meat consumption. The present study investigated whether having a close vs. a distant social group as the referent changed perceptions of social norms around making healthy and eco-friendly food choices. It also assessed whether these changes were associated with a difference in the health and environmental impacts of food choice in a virtual grocery shopping task. A nationally representative sample of UK adults (N = 2,488) reported their perceptions of making healthy and eco-friendly food choices being the norm among people they share meals with (close referent group) and most people in the UK (distant referent group). The former was more commonly perceived to be making both healthy (Z = -12.0, p < 0.001) and eco-friendly (Z = -13.27, p < 0.001) food choices than the latter. Perceptions of norms referring to the close group were significantly associated with the environmental (β = -0.90, 95% CIs: -1.49, -0.28) and health (β = -0.38 p < 0.05, 95% CIs: -0.68, -0.08) impacts of participants' food choices in a virtual shopping task. No such relationship was found for norms referring to the distant group for both environmental (β =0.43, p > 0.05, 95% CIs: -1.12, 0.25) and health (β = -0.06, p > 0.05, 95% CIs: -0.37, 0.25) impacts. Framing social norms around making healthy and eco-friendly food choices to refer to a close referent group may change their perceptions and ability to encourage sustainable and healthy food purchasing.

You Are What You Eat… But Do You Eat What You Are? The Role of Identity in Eating Behaviors—A Scoping Review

Background: Identity is a major construct in the fields of psychology and anthropology that can relate to both the maintenance of eating behaviors and cultural sensitivity. However, there has not been any systematic effort to understand the role of identity in eating behaviors and the maintenance of eating behaviors, or to address multiple aspects of identity within an individual across scientific disciplines. This scoping review aims to understand and describe existing research relating identity to eating behaviors and to detail the measurement of identity. Methods: We conducted a systematic search of Ovid, PsychINFO, Embase, and Web of Science for articles on identity and eating behaviors published between January 1946 and March 2022. We utilized the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist, and search methods were developed with the assistance of a research librarian. We rated articles from 1 to 5 based on the depth, complexity, and multi-dimensionality of the identity measurement conducted. Scoring criteria included a review of the number of items directly querying or evaluating identity and the extent of measurement of identity domains. Results: In total, 100 articles were included, examining 10 different identities, 8 identity constructs, 11 eating behaviors, and construct contributions from 26 theories. The mean score of all articles was 2.9 on the scale from 1 to 5. A total of 10 studies scored a “1”; 30 scored a “2”, indicating the use of 1–2 basic questions about identity; 31 received a “3” for use of a common but non-complex identity instrument; 19 received a “4”, meaning they contained strong evaluation and included multiple types of identity but were lacking in terms of depth of measure and/or the comparison of identity effects to constructs; and 10 scored a “5” for their strong, in-depth measure of identity and inclusion of multiple types. Identity was found to be significantly related to eating behaviors in all but one study. Conclusion: Identity measurements seldom accounted for complexities such as multiple identities and identity shifting over time. Nonetheless, our findings indicate that multiple aspects of identity reciprocally reinforce behavior and that change maintenance is associated with identity salience and centrality. Identity is underutilized and heterogeneously applied in eating behavior research. The inclusion of identity assessments may lead to better outcomes being obtained within differing cultural, normative, and environmental scenarios.

A Social Norms and Identity Approach to Increasing Fruit and Vegetable Intake of Undergraduate Students in the United Kingdom

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.

How food overconsumption has hijacked our notions about eating as a pleasurable activity

The negative effects of overconsumption of food have been extensively studied, with a focus on overweight and negative food attitudes. In this overview, we argue that this negative perspective has spilled over to food consumption in general, which is in contrast with eating as a pleasurable activity that contributes to people's well-being. We review four areas of research that have recently emerged: (de)moralization of food consumption, moderate eating for pleasure, intuitive and mindful eating, and the social benefits of eating. Throughout these four themes, it becomes clear that there needs to be a clear distinction between overconsumption of food, bearing negative consequences, and normal levels of food consumption. The latter is positively associated with enjoyment, contentment, and our social and psychological well-being.

Police Decision-Making in the Absence of Evidence-Based Guidelines: Assessment of Alcohol-Intoxicated Eyewitnesses

Regarding police procedures with alcohol-intoxicated witnesses, Swedish police officers have previously reported inconsistent and subjective decisions when interviewing these potentially vulnerable witnesses. Most officers have also highlighted the need for national policy guidelines aiding in conducting investigative interviews with intoxicated witnesses. The aims of the two studies presented here were to investigate whether (1) police officers' inconsistent interview decisions are attributable to a lack of research-based knowledge; (2) their decision to interview, as well as their perceptions of the witnesses' credibility could be influenced by scientific research; and (3) police officers decision-making and perceptions of witness credibility are biased by pre-existing social norms. In two separate randomized online experiments, police professionals and recruits (Study 1, N = 43; Study 2, N = 214) watched a recorded fictive witness interview to which they were asked to rate the probability of interviewing the witness, the witness' credibility, and to estimate the witness' level of intoxication. Results showed that interview probability and perceived witness credibility were affected by witness intoxication level. While it cannot be stated definitely from the present research, these findings provided indications that police officers and recruits lacked research-based knowledge. Results also showed that interview probability, but not perceptions of credibility, was influenced by a research-based message. In line with research, interview probability for the most intoxicated witness increased after reading the message. Unexpectedly, neither interview probability nor witness credibility was affected by social norms. The current findings added to the legal psychology literature by showing that a breath alcohol concentration (BrAC) as low as .04% was enough for police officers and recruits to consider intoxicated witnesses less credible than sober witnesses. Findings also indicated that, despite the lower credibility assessment, police may have some understanding that these witnesses can be interviewed at low intoxication levels (i.e., around .04%). However, this willingness to interview intoxicated witnesses ceased at a BrAC lower than the levels where research has found intoxicated witnesses as reliable as sober witnesses (i.e., BrAC < .10%). Future directions for research and policy development as well as theoretical and practical implications of the present findings are discussed.

Can Social Cognitive Theory Influence Breakfast Frequency in an Institutional Context: A Qualitative Study

Breakfast is considered an important meal, especially for people who are about to commence a long or demanding workday, and for roles that may involve physical tasks and a requirement to remain alert and vigilant in potentially high-risk situations. This study looks at breakfast consumption influences within two workplace institutional settings, namely military and mining. Semi-structured interviews were conducted with military personnel (n = 12) and mining employees (n = 12) to understand their breakfast consumption behaviour at work and at home, and the associated behavioural influences. The interview questions were framed by social cognitive theory. Overall, cognitive and environmental influences were the most prominent influences on breakfast consumption, less evident were behavioural influences. A negative stereotype of workplace institutional food services emerged as one of the most significant barriers to breakfast consumption for those already at work. Considerations of environmental influences on behaviour may need to be broadened beyond physical barriers and social influences, to include perceptions of the behavioural environment. Programs that aim to increase breakfast consumption must create areas where their employees want to go. Food systems need to ensure nutritious, quality, and appealing food is available. Interventions need to increase participants’ knowledge, improve their attitudes, and create positive expectations for breakfast.

The effect of descriptive norms and social identification on performance and exertion during a physical fitness task

Research suggests that people's perceptions of the typical physical activity behaviors of others-descriptive norms-shape their own physical activity. However, prior work has primarily used cross-sectional designs, focused on people's physical activity intentions or self-reported overall physical activity, and failed to attend to how the normative referent affects the norm-behavior relationship. In a pre-registered experiment, we manipulated the descriptive norm to explore its effect on perceived exertion during, and objectively assessed performance on, an exercise (running) task. We also measured the strength of participants' social identification as a member of the norm reference group as a potential moderator. Following a baseline trial, participants (N = 78) were either told that their baseline score on the running task was below average (high norm condition) or above average (low norm condition) compared to members of the reference group. Participants in both conditions tended to perform better in Trial 2 than Trial 1. However, participants in the high norm condition improved their performance significantly (2.5 times) more than participants in the low norm condition. Social identification moderated the effect of the norm manipulation on perceived exertion. High identifiers tended to exert themselves less than low identifiers during Trial 2 if they were told they were above average, whereas if told they were below average, high identifiers exerted themselves slightly more than low identifiers. Results provide evidence that descriptive norm messages can improve people's performance on physically demanding tasks, and indicate that descriptive physical activity norms may be more influential when the norm reference group is subjectively meaningful. Opportunities to fruitfully deploy norm messages in applied contexts are discussed.

Increasing vegetables purchase with a descriptive-norm message: A cluster randomized controlled intervention in two university canteens

Exposure to social norms is a popular way to foster healthy food behavior. Testing the robustness of this effect, we report a field study assessing the impact of a vegetable-related descriptive norm message on vegetables purchase. The first contribution was to rely on a cluster randomized crossover design: Two canteens were randomly selected to display either a vegetable-related or a neutral-behavior norm message. After a first period of data collection, the displays were reversed for a second period: The number of vegetable portions on the main plate were recorded before, during and after the message display (N = 12.994). The second contribution was to test the impact of a message describing vegetables as the normative choice beyond the mere selection of vegetables, on the quantity of vegetables purchased in lunches containing some. Results indicated that the vegetable-related norm message led to a sustained probability of choosing vegetables, contrary to a decrease observed in the control condition. Moreover, students who ordered vegetables ordered a higher quantity when exposed to a vegetable-related message than before whereas quantity declined in the control condition. By treating both canteens as experimental and control and by analyzing both the presence and the amount of vegetables, these results extend and strengthen those previously observed, bringing support for the effectiveness of a descriptive norm message in eliciting healthier food behavior.

Creativity and Leadership in the Creative Industry: A Study From the Perspective of Social Norms

Individual creativity has been the focus of long-term research in creative industries. However, few studies have explored the impact on individual creativity from social factors. At the same time, the influence of individual creativity on the existence of subsequent factors in the creative industry is also worthy of further investigation. From a social standpoint, this research aims to explore how social norms affect individual creativity, and how individual creativity affects subsequent leadership. The present research takes creative entrepreneurs in creative enterprises as the research objects, and the structural equation model is used to analyze the data obtained from 202 valid questionnaires. Besides, the mediating effect of individual creativity between social norms and individual leadership is verified. The results show that social norms can effectively promote the generation of individual creativity that has a positive impact on both transactional or transformational leadership. It is revealed that social norms are effective tools for enhancing creativity, answering the question of how creative ideas are transformed into creative work and leadership. Individual creativity plays a mediating role between social norms and individual leadership.