Minority talks: The influence of descriptive social norms on fruit intake

A fist bump in a political meeting? The influence of social context on affordance selection

Historically, understanding human cognition such as action processing has been a challenging issue in cognitive neuropsychology and the more we know about cognition, the more we shape it as a complex, multi-determined phenomenon that is embedded in a social context. The present study aimed at understanding how the social context could influence affordance selection. We hypothesized that affordance selection would be modulated by social context and that a given hand configuration would be considered appropriate or not, as a function of the presence or absence of social context. Twenty-six healthy participants were asked to judge the appropriateness of three variants of 10 hand-object interactions based on photographs presented with or without a visual, social context. In our results, hand configurations were intrinsically acceptable or not, but this effect was modulated by the social context. A three-step model of the influence of social context on affordance selection was proposed, according to which selection depends on social norms, in the form of social knowledge and social context analysis.

Assessment of Nutritional Status and Health Perception among Male Inmates in Israeli Prisons

The nutritional and health perceptions of inmates are crucial to their overall well-being. However, limited research has been conducted on this topic. This study aimed to assess the nutritional and health perception state of male inmates in eleven prisons in Israel. A cross-sectional study was conducted between February and September 2019 with 176 voluntary participants. Structured questionnaires were used to collect data on socio-demographic characteristics, healthy habits, subjective health status, and prison situation variables. The study found that the prevalence of overweight (40%) and obesity (18.1%) among 18-34-year-old inmates was significantly higher than in the reference Israeli population. Short detention periods (up to one year) predicted less weight gain, while older age predicted poorer health status. Better emotional status significantly predicted better subjective health status among male inmates. There is a need for nutrition interventions to improve the health of inmates. The significant weight gain during incarceration and the associated lower health index and stress highlights the importance of increasing knowledge and promoting a healthier lifestyle in incarceration as early as possible and continuing over time.

Regional Living Conditions and Individual Dietary Characteristics of the Russian Population

The goal of our study was to examine the effects of the regional characteristics of the living environment on individual a priori and a posteriori dietary patterns of the Russian population. For the analysis, we used cross-sectional data from the Epidemiology of Cardiovascular Diseases in the Regions of the Russian Federation study from 2013-2014. The sample included 18,054 men and women 25-64 years of age from 12 regions. Based on the frequency of consumption of basic foods, four a posteriori empirical dietary patterns (EDPs), along with an a priori cardioprotective dietary pattern (CPDP), were identified. To describe the regional living environment, five regional indices were used. Adherence to the meat-based EDP was directly associated with deterioration of social living conditions and a more northerly location for the region of residence. The probability of a CPDP increased with greater deterioration of social living conditions, aggravation of demographic crises, and higher industrial development in the region, as well as with declines in the economic development of the region, income, and economic inequality among the population. We detected several gender-dependent differences in the associations established. The patterns revealed reflect the national dietary preferences of Russians, and the regional indices characterize the effect of the living environment.

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.

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.

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.

Context Matters for Food Security: Multi-Sited Evidence of Shared Cultural Models of Food Consumption

Anthropologists have long emphasized the social significance of foods and the contexts in which they are consumed. Expanding on this idea, we define the context of consumption as the non-eating behaviors that surround eating, such as the manner of food preparation, food sharing, and dietary patterns. In this study, we used cultural consensus analysis to assess whether there exist consistently shared, normative ideas about preferable context of food consumption in three diverse research sites: urban Ethiopia, rural Brazil, and rural Haiti. Our analysis demonstrates that in all three communities, there are distinct sets of behaviors that people identified as non-preferable because they reliably associate them with poverty and food insecurity, and behaviors that people identify as preferable because they reliably associate them with wealth and food security. Across the settings, there was little variation in agreement about behaviors across household composition, age, gender, and food security status. These findings suggest that people do indeed share culturally specific ideas about the context in which foods should be prepared and consumed, beyond the actual content of one's diet. Exploring these cultural models elucidates the social consequences of food insecurity, enabling researchers to better examine the relationship between food insecurity, social context, and well-being.

Guess What …?—How Guessed Norms Nudge Climate-Friendly Food Choices in Real-Life Settings

Social norms, also called social comparison nudges, have been shown to be particularly effective in promoting healthy food choices and environmentally friendly behaviors. However, there is limited evidence on the effectiveness of these nudges for promoting sustainable and climate-friendly food choices and their potential to reduce greenhouse gas emissions and support the related SDGs. The paper reports a field experiment that tests the effectiveness of two social norms in a real-life setting based on revealed preferences. The study distinguishes between the widely researched descriptive norms and guessed norms, the latter being tested in this context for the first time. While descriptive norms communicate typical patterns of behavior (e.g., 50% of canteen visitors choose vegetarian meals), guessed norms are determined by the individual’s best guess about the norm in a specific context. The results confirm a remarkable nudging effect of guessed norms: The higher the presumed proportion of vegetarian dishes sold, the lower the probability of choosing a vegetarian dish. Surprisingly, this effect is independent of the respective norm specification (meat or vegetarian norm). The paper provides advice for policy makers about when and how to use guessed norms.

Unpacking the "black box" of global food insecurity and mental health

Food insecurity is a global concern. While it was once characterized mainly as a problem of undernutrition, it is now recognized that a person may be food insecure without experiencing hunger. Numerous studies have demonstrated that food insecurity is strongly related to poor mental health around the world, but the mechanisms that underpin that relationship remain poorly understood. One body of research from nutritional sciences posits that nutrient deficiency impacts brain function, producing symptoms of depression and anxiety. Another body of research from the social sciences posits that the social consequences of having to eat non-preferred foods or obtain food in socially unacceptable ways may compromise mental health through stress. This study was designed to clarify the mechanisms linking food insecurity and mental health using case studies in rural Brazil and urban Ethiopia. Working with samples consisting of about 200 adult household decision-makers (mostly female) recruited between 2015 and 2019 at each site, we tested for nutritional and social mediation of the food insecurity-mental health relationship using multivariable linear regression and mediation analysis. Our analyses found no evidence of mediation in either setting. Moreover, there was no association between nutritional status variables and food insecurity. These findings suggest that food insecurity likely impacts mental health directly through forms of basic needs deprivation, such as worrying about where one's next meal will come from, rather than by acting as a social signal or even by impacting nutritional status. These results underscore the power of basic-needs deprivation for impacting mental health.

Understanding eating and drinking behaviours in Pakistani university students: A conceptual model through qualitative enquiry

Excess weight in Pakistan's university students is on the rise and is driven by their maladaptive eating behaviours. Practitioners in Pakistan have adopted Western conceptual models to understand obesogenic eating behaviours. However, these models provide incomplete explanations as they miss important culturally specific determinants for such eating behaviours. The goals of this study were two-fold: first, to explore Pakistani university students' perception of their obesity-related eating behaviours and attitudes; second, to develop a culturally sensitive model of obesogenic eating behaviours in university students from Pakistan. Semi-structured interviews were used with twenty-four Pakistani university students who were categorised as obese using the Body Mass Index according to Asia-Specific cut-offs. Interviews were transcribed, translated, and then analysed through a Grounded Theory methodology. Six major categories emerged from interviews: (1) Obesogenic Eating Habits (Social Eating, Emotional Eating, and Eating Whatever and Whenever You Want); (2) Beliefs about Food in the Culture; (3) Neither Too Fat nor Too Thin body belief (4) Student Life Attitudes; (5) Student Stressors; (6) Inconsistent Weight-Control Strategies. A model was developed with cultural beliefs about food, attitudes towards student-life, and stressors as important determinants of students' obesogenic eating habits, while inconsistent weight-control strategies contributed to further weight gain. The findings highlight the importance of identifying culturally specific determinants of eating behaviours among university students in Pakistan. This emerging model can be used to guide the development of future quantitative and also longitudinal studies aimed at identifying targets for therapeutic interventions to manage obesogenic eating behaviours in Pakistani university students.

Hopes and reality: consumers’ purchase intention towards whitening cream

In contemporary Bangladeshi society, popularity, marriage, and status are weighed on a scale where the vital criterion is a fair complexion. Women are encouraged to use whitening cream in its colour-conscious culture. The present study identifies the factors that influence consumers’ purchase intention towards whitening cream. A structured questionnaire was used to elicit feedback from 275 female respondents using the convenience sampling method. Structural equation modelling and hypotheses tests were conducted to validate the model after verifying the scale items’ reliability and validity. The findings revealed that attitude, involvement, and descriptive norms were significant factors, and injunctive norms, perceived quality, and price fairness were inessential factors in explaining Bangladeshi female consumers’ purchase intention. The framework used in the study can assist in product design. The study makes an important contribution to the literature by explaining why female consumers equate whiteness with beauty. Marketers should not use deceptive advertisements to influence them falsely; they should fulfil their expectations without causing harm or inciting racism.

Managing Procrastination on Social Networking Sites: The D-Crastinate Method

Procrastination refers to the voluntary avoidance or postponement of action that needs to be taken, that results in negative consequences such as low academic performance, anxiety, and low self-esteem. Previous work has demonstrated the role of social networking site (SNS) design in users’ procrastination and revealed several types of procrastination on SNS. In this work, we propose a method to combat procrastination on SNS (D-Crastinate). We present the theories and approaches that informed the design of D-Crastinate method and its stages. The method is meant to help users to identify the type of procrastination they experience and the SNS features that contribute to that procrastination. Then, based on the results of this phase, a set of customised countermeasures are suggested for each user with guidelines on how to apply them. To evaluate our D-Crastinate method, we utilised a mixed-method approach that included a focus group, diary study and survey. We evaluate the method in terms of its clarity, coverage, efficiency, acceptance and whether it helps to increase users’ consciousness and management of their own procrastination. The evaluation study involved participants who self-declared that they frequently procrastinate on SNS. The results showed a positive impact of D-Crastinate in increasing participants’ awareness and control over their procrastination and, hence, enhancing their digital wellbeing.

Preadolescents' healthy eating behavior: peeping through the social norms approach

BACKGROUND

The rising childhood obesity rate is a major public health challenge. The objective of this study is to examine key underlying mechanisms for peer-related social influence on preadolescents' healthy eating behavior by including factors closely linked with the quality of preadolescents' relationship with peers.

METHODS

A cross-sectional study was conducted in a convenience sample of 278 Lithuanian preadolescents, recruited from a public school. A questionnaire containing sociodemographic questions, questions about food intake, peer-related social norms of healthy eating, social self-efficacy, vegetable preference, need for peer approval and feeling of belonging were applied. Data was analyzed using structural equation modeling.

RESULTS

The results of the SEM showed that social self-efficacy predicts feeling of belonging to the peer group and need for peer approval. Feeling of belonging and need for peer approval predict actual intake of vegetables via injunctive norms of healthy eating. However, neither feeling of belonging nor need for peer approval predicted descriptive norms of healthy eating. Contrary to our expectations, descriptive norms were found to be unrelated with actual intake of vegetables, though vegetable preference predicted actual intake of vegetables. Vegetable preference was not predicted by injunctive or descriptive peers' social norms of healthy eating.

CONCLUSIONS

The findings of this study offer insight for informing parents, teachers and for social norms marketing interventions by stressing the importance of social relations when the aim is to encourage healthy eating among preadolescents.

The impact of descriptive norms on motivation to participate in cancer screening - Evidence from online experiments

OBJECTIVE

The current study tested in two online experiments whether manipulating normative beliefs about cancer screening uptake increases intention to attend colorectal screening among previously disinclined individuals.

METHODS

2461 men and women from an Internet panel (Experiment 1 N = 1032; Experiment 2, N = 1423) who initially stated that they did not intend to take up screening were asked to guess how many men and women they believe to get screened for colorectal cancer. Across participants, we varied the presence/absence of feedback on the participant's estimate, as well as the stated proportion of men and women doing the screening test.

RESULTS

Across the two experiments, we found that receiving one of the experimental messages stating that uptake is higher than estimated significantly increased the proportion of disinclined men and women becoming intenders. While, we found a positive relationship between the communicated uptake and screening intentions, we did not find evidence that providing feedback on the estimate has an added benefit.

CONCLUSION

Screening intention can be effectively manipulated through a high uptake message.

PRACTICE IMPLICATIONS

Communication of high screening uptake is an easy and effective way to motivate disinclined individuals to engage in colorectal cancer screening.

An Exploratory Study Examining the Interactive Effect of Descriptive Norm and Image Appeal Messages on Adults' Physical Activity Intentions: A Test of Deviation Regulation Theory

This exploratory study examined the interaction between messages conveying descriptive norms and image appeals on adults' physical activity intentions. Using a pre-post experimental design, insufficiently active adults (N = 204) were randomly assigned to receive one of four messages, which included both a descriptive norm (prevalence of physical activity: high vs. low) and an image appeal (personality attributes: positive vs. negative). The results from an analysis of covariance, controlling for baseline physical activity intentions, revealed a significant interaction. Post-hoc analyses indicated that when the image appeal was positive, those who received the low descriptive norm had greater physical activity intentions than the high descriptive norm condition. No significant interaction was found for negative image appeals. Results provide preliminary evidence that physical activity intentions can be positively influenced even when physical activity is not considered the norm. Messages that include low descriptive norm information may benefit from including positive image appeals of those who do engage in physical activity, if aiming to increase physical activity intentions in insufficiently active adults.

Contributions of personality to social influence: Contingent associations between social network body size composition and BMI

Social influence is a key determinant of health behaviors and outcomes. Research in the social network tradition emphasizes social structural mechanisms like network content (i.e., the degree to which particular attitudes, attributes, or behaviors are present in the network) and social proximity (i.e., opportunities for social interaction). In contrast, psychologists are oriented toward the individual, identifying how personality traits like self-monitoring affect susceptibility to peer pressure. Here, we integrate social network and personality approaches, examining social influence on body size using surveys of 379 adults with dependent children. Our findings suggest that the association between social network body size composition and respondent BMI is contingent on both individual susceptibility to influence (i.e., high self-monitoring) and social proximity (i.e., opportunities for co-eating). These results indicate that individuals embedded in social networks bring unique sets of social skills and orientations to interactions, potentially influencing the flow of content across networks.

Social Modeling of Food Intake: No Evidence for Moderation by Identification With the Norm Referent Group

Normative information has a powerful effect on food intake and food selection. People tend to use the eating behavior of others as a reference for their own eating behaviors and match their intake to an eating partner. This is known as social modeling. There is some evidence to suggest that people are more likely to model a norm when it comes from an in-group than when it comes from an out-group, but whether the strength of identification with a norm referent group moderates modeling of intake has yet to be examined. The current paper presents the results of two studies that investigated whether modeling of intake is moderated by strength of identification with the norm referent group. In Study 1, we recruited 90 female students from the University of Birmingham (UoB) (mean age = 21). Students were allocated to either a low norm condition (presented with a sheet that presented a low cookie intake of previous participants) or a high norm condition (presented with a sheet that presented a high cookie intake of previous participants), or a no norm condition (control group without the sheet containing information about previous participants’ cookie intake). Students also completed a questionnaire on their identification as a Birmingham student and cookie intake was assessed. In Study 2, we recruited 84 students (mean age = 21) who were randomly allocated to one of two conditions (a group presented with a high norm for vegetable intake or no information about a vegetable intake norm). Strong modeling effects were found across both studies but the extent to which the participants identified as a Birmingham University Student did not moderate these effects. The moderating effect of social identity on modeling of eating might be context-dependent.

Sexual health information-seeking behavior on a social media site: predictors of best answer selection

Purpose

The purpose of this paper is to identify sexual health information needs and the cognitive and affective factors correlated with the best answer chosen by social Q&A users.

Design/methodology/approach

The study collected questions and answers regarding sexual health information on a social Q&A site, and analyzed the questions and a paired sample composed of best and non-best answers (n=480).

Findings

The main information needs of consumers are human development, sexual behavior, and sexual health. Best answers are more likely to include both cognitive (higher level of readability, risky information, social norms) and affective factors (empathy, positive/negative feelings, and optimistic information) than non-best answers.

Research limitations/implications

The study illuminates the roles of social Q&A as a unique platform to discuss sensitive health topics due to the fact that consumers use such social media sites as critical complementary health information sources.

Practical implications

If health information providers develop information with the factors that the study suggests, not only will it be more adopted by consumers, but it will also ameliorate the quality concerns about online health information.

Originality/value

Previous studies only investigated the most prevalent factors, rather than the most effective ones, which have a greater influence on best answer selection. This study compares the best answers and the non-best answers to overcome the limitations of the previous studies. Above all, the study applied the persuasion concepts to address the cognitive and affective perspectives to the answer evaluations of social Q&A.

A Social Norms Intervention Going Wrong: Boomerang Effects from Descriptive Norms Information

A large body of research supports the idea of social norms communication promoting pro-social and pro-environmental behaviour. This paper investigates social norms communication in the field. Signs prompting consumers about sustainable seafood labels and informing them about other consumers’ sustainable choices were displayed in supermarkets in Norway and Germany. Seafood sales (sustainably labelled versus unlabelled products) were observed before, during, and after the implementation of the signs. The expected change towards more sustainable choices was generally not found. In Norway, the choice of sustainable seafood increased in the prompt-only condition, but the effect was neutralised when social norms information was added. In Germany, social norm messages lead to a decline in sustainable choices compared to baseline, a boomerang effect. Overall, an increase in the purchase of seafood (both sustainably labelled and unlabelled) was noted during the intervention. A second study was carried out to further explore the finding that consumers were mainly primed with “seafood” as a food group. In a laboratory setting, participants were confronted with stereotypical food pictures, combined with short sentences encouraging different consumption patterns. Subsequently, they were asked to choose food products in a virtual shop. Confirming the findings of Study 1, participants chose more of the groceries belonging to the food group they were primed with. These studies suggest that social norms interventions—recently often perceived as “the Holy Grail” for behaviour change—are not as universally applicable as suggested in the literature. According to this study, even descriptive norm messages can produce boomerang effects.

Eating for Two? Protocol of an Exploratory Survey and Experimental Study on Social Norms and Norm-Based Messages Influencing European Pregnant and Non-pregnant Women's Eating Behavior

The social context is an important factor underlying unhealthy eating behavior and the development of inappropriate weight gain. Evidence is accumulating that powerful social influences can also be used as a tool to impact people's eating behavior in a positive manner. Social norm-based messages have potential to steer people in making healthier food choices. The research field on nutritional social norms is still emerging and more research is needed to gain insights into why some people adhere to social norms whereas others do not. There are indications stemming from empirical studies on social eating behavior that this may be due to ingratiation purposes and uncertainty reduction. That is, people match their eating behavior to that of the norm set by their eating companion(s) in order to blend in and be part of the group. In this project, we explore nutritional social norms among pregnant women. This population is particularly interesting because they are often subject to unsolicited advice and experience social pressure from their environment. In addition, their pregnancy affects their body composition, eating pattern, and psychosocial status. Pregnancy provides an important window of opportunity to impact health of pregnant women and their child. Nevertheless, the field of nutritional social norms among pregnant women is understudied and more knowledge is needed on whether pregnant women use guidelines from their social environment for their own eating behavior. In this project we aim to fill this research gap by means of an exploratory survey (Study 1) assessing information about social expectations, (mis)perceived social norms and the role of different reference groups such as other pregnant women, family, and friends. In addition, we conduct an online experiment (Study 2) testing to what extent pregnant women are susceptible to social norm-based messages compared to non-pregnant women. Moreover, possible moderators are explored which might impact women's susceptibility to social norms as well as cultural aspects that co-determine which social norms and guidelines exist. The project's findings could help design effective intervention messages in promoting healthy eating behavior specifically targeted to European pregnant women.

Social approval bias in self-reported fruit and vegetable intake after presentation of a normative message in college students

OBJECTIVE

To determine the accuracy of self-reported data regarding Fruit and Vegetable (FV) intake in college students at Utah State University after being presented with a descriptive normative message.

INTERVENTION

Participants (N = 167) were recruited from general education courses and asked to complete a baseline survey containing a FV screener from the National Cancer Institute. They were then randomized to receive one of four messages one week after the initial survey and asked to immediately complete the same FV screener. The Control group received no FV message. The Recommendation group received a message that the recommendation for FV is 4-5 cups per day. The two normative groups received a message that either 80% of students ate more (Low) or less (High) FV than they did, regardless of actual intake, in addition to the recommended intake.

ANALYSIS

Repeated measures ANOVA was used to assess differences in reported FV intake and perceived FV intake of peers between the first and second assessment.

RESULTS AND CONCLUSIONS

Those receiving the message that they were in the lowest 20th percentile of intake reported a half-cup increase in self-reported FV intake and a one-cup increase in perception of peers' intake (p = 0.037 and p=<0.001, respectively). No significant differences were observed in other groups. These results indicate that normative messaging may influence self-reported FV intake and perception of peer intake of college students when this message indicates that the participant is in the lowest percentile of their peers.

The social image of food: Associations between popularity and eating behavior

One factor that determines what we eat and why we eat is our social environment. In the present research, two online studies examined the relationship between food intake and social images. Specifically, the present research assessed the relationship between the food intake university students ascribed to peers who varied in popularity and own self-reported food intake, and whether this relationship was moderated by identification with the peer group. Participants (N = 97 in Study 1; N = 402 in Study 2) were randomly presented with one of four (Study 1) or two of eight (Study 2) vignettes describing a popular or unpopular student (male or female) from their university without receiving any information about the peer's eating behavior. Subsequently, healthy and unhealthy eating ascribed to the peers and own self-reported eating behavior were assessed. Results indicated that popular peers were perceived to eat more healthily than unpopular peers. Moreover, eating behavior ascribed to popular peers were associated with own healthy and unhealthy eating. Importantly, the relationship between healthy eating behavior ascribed to popular peers and own healthy eating behavior was moderated by identification with the student group - the more participants identified with their peers, the more their own eating was aligned with the healthy eating ascribed to a popular peer. Hence, the popularity of others seems to shape perceptions of the food they eat and may facilitate healthy eating via social influence.

The Longitudinal Associations between Perceived Descriptive Peer Norms and Eating and Drinking Behavior: An Initial Examination in Young Adults

Experimental and cross-sectional studies indicate that perceptions of the eating and drinking behavior of one's peers (perceived descriptive peer norms) are associated with the types, frequency and quantity of food, and beverages a person chooses to consume. At present, we know very little about the longitudinal association between perceived descriptive peer norms and future eating or drinking behavior. In this study, we examined whether perceived descriptive peer norms for different food/beverage types predicted frequency of consumption of food/beverages in university students. Three hundred and forty participants completed measures at baseline and follow-up for frequency of consumption of cakes/pastries, sugar containing beverages, and alcoholic beverages, as well as measures of perceived descriptive peer norms at both time points. Perceived descriptive peer norms predicted consumption of pastries/cakes at follow up when controlling for changes in these perceptions over time; believing that one's peers frequently consumed cakes/pastries was associated with an increased frequency of consumption over time, although the magnitude of this effect was small. There was no significant association between perceived descriptive peer norms and changes in frequency of consumption of sugar containing beverages or alcohol over time. In the present longitudinal study of young adults, beliefs about how often one's peers eat or drink specific food and beverages types had limited effect on future eating and drinking behavior.

Personality and Social Framing in Privacy Decision-Making: A Study on Cookie Acceptance

Despite their best intentions, people struggle with the realities of privacy protection and will often sacrifice privacy for convenience in their online activities. Individuals show systematic, personality dependent differences in their privacy decision making, which makes it interesting for those who seek to design 'nudges' designed to manipulate privacy behaviors. We explore such effects in a cookie decision task. Two hundred and ninety participants were given an incidental website review task that masked the true aim of the study. At the task outset, they were asked whether they wanted to accept a cookie in a message that either contained a social framing 'nudge' (they were told that either a majority or a minority of users like themselves had accepted the cookie) or contained no information about social norms (control). At the end of the task, participants were asked to complete a range of personality assessments (impulsivity, risk-taking, willingness to self-disclose and sociability). We found social framing to be an effective behavioral nudge, reducing cookie acceptance in the minority social norm condition. Further, we found personality effects in that those scoring highly on risk-taking and impulsivity were significantly more likely to accept the cookie. Finally, we found that the application of a social nudge could attenuate the personality effects of impulsivity and risk-taking. We explore the implications for those working in the privacy-by-design space.

Which Combinations of Techniques and Modes of Delivery in Internet-Based Interventions Effectively Change Health Behavior? A Meta-Analysis

Background

Many online interventions designed to promote health behaviors combine multiple behavior change techniques (BCTs), adopt different modes of delivery (MoD) (eg, text messages), and range in how usable they are. Research is therefore needed to examine the impact of these features on the effectiveness of online interventions.

Objective

This study applies Classification and Regression Trees (CART) analysis to meta-analytic data, in order to identify synergistic effects of BCTs, MoDs, and usability factors.

Methods

We analyzed data from Webb et al. This review included effect sizes from 52 online interventions targeting a variety of health behaviors and coded the use of 40 BCTs and 11 MoDs. Our research also developed a taxonomy for coding the usability of interventions. Meta-CART analyses were performed using the BCTs and MoDs as predictors and using treatment success (ie, effect size) as the outcome.

Results

Factors related to usability of the interventions influenced their efficacy. Specifically, subgroup analyses indicated that more efficient interventions (interventions that take little time to understand and use) are more likely to be effective than less efficient interventions. Meta-CART identified one synergistic effect: Interventions that included barrier identification/ problem solving and provided rewards for behavior change reported an average effect size that was smaller (ḡ=0.23, 95% CI 0.08-0.44) than interventions that used other combinations of techniques (ḡ=0.43, 95% CI 0.27-0.59). No synergistic effects were found for MoDs or for MoDs combined with BCTs.

Conclusions

Interventions that take little time to understand and use were more effective than those that require more time. Few specific combinations of BCTs that contribute to the effectiveness of online interventions were found. Furthermore, no synergistic effects between BCTs and MoDs were found, even though MoDs had strong effects when analyzed univariately in the original study.

The Role of Social Norms in the Portion Size Effect: Reducing Normative Relevance Reduces the Effect of Portion Size on Consumption Decisions

People typically eat more from large portions of food than from small portions. An explanation that has often been given for this so-called portion size effect is that the portion size acts as a social norm and as such communicates how much is appropriate to eat. In this paper, we tested this explanation by examining whether manipulating the relevance of the portion size as a social norm changes the portion size effect, as assessed by prospective consumption decisions. We conducted one pilot experiment and one full experiment in which participants respectively indicated how much they would eat or serve themselves from a given amount of different foods. In the pilot (N = 63), we manipulated normative relevance by allegedly basing the portion size on the behavior of either students of the own university (in-group) or of another university (out-group). In the main experiment (N = 321), we told participants that either a minority or majority of people similar to them approved of the portion size. Results show that in both experiments, participants expected to serve themselves and to eat more from larger than from smaller portions. As expected, however, the portion size effect was less pronounced when the reference portions were allegedly based on the behavior of an out-group (pilot) or approved only by a minority (main experiment). These findings suggest that the portion size indeed provides normative information, because participants were less influenced by it if it communicated the behaviors or values of a less relevant social group. In addition, in the main experiment, the relation between portion size and the expected amount served was partially mediated by the amount that was considered appropriate, suggesting that concerns about eating an appropriate amount indeed play a role in the portion size effect. However, since the portion size effect was weakened but not eliminated by the normative relevance manipulations and since mediation was only partial, other mechanisms may also play a role.

Encouraging children to eat more fruit and vegetables: Health vs. descriptive social norm-based messages

Traditional intervention approaches to promote fruit and vegetable consumption outline the health benefits of eating fruit and vegetables. More recently, social norm-based messages describing the healthy eating habits of others have been shown to increase fruit and vegetable intake in adults. Here we report two experimental studies which investigated whether exposure to descriptive social norm-based messages about the behaviour of other children and health-based messages increased fruit and vegetable intake in young children. In both studies children were exposed to messages whilst playing a board-game. After exposure to the messages, children were able to consume fruit and vegetables, as well as high calorie snack foods. Although findings were inconsistent across the two individual studies, in a pooled analysis we found evidence that both health messages and descriptive social norm-based messages increased children's fruit and vegetable intake, relative to control condition messages (p < .05). Whether descriptive social norm-based messages can be used to promote meaningful changes to children's dietary behaviour warrants further study.

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Descriptive social norm-based and health messages were examined.

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Health messages increased fruit and vegetable intake.

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Descriptive social norm-based messages increased fruit and vegetable intake.

Effects of Previous Fruit Intake, Descriptive Majority Norms, and Message Framing on Fruit Intake Intentions and Behaviors in Dutch Adults Across a 1-Week Period

OBJECTIVE

To test the effects of descriptive norm and message framing on fruit intake (intentions) in Dutch adults.

DESIGN

Randomized pretest-posttest study using a 2 × 2 design.

SETTING

Internet-based.

PARTICIPANTS

Dutch adults recruited via leaflets and announcements on intranet and Internet and who provided immediate intention (n = 294) and 1-week follow-up intention and fruit intake data (n = 177).

INTERVENTION

Messages combining information on intake of others (low vs high intake) with information about positive or negative outcomes of (in)sufficient fruit intake.

MAIN OUTCOME MEASURES

Fruit intake intentions and fruit intake.

ANALYSIS

Analyses of covariance.

RESULTS

Those already consuming sufficient fruit and receiving negative information about insufficient fruit intake increased their motivation to consume sufficient fruit immediately (P = .03), but not at 1-week follow-up. Those who read positive information about sufficient fruit intake reported higher fruit consumption than those who read negative information about insufficient fruit intake (P = .03). This was stronger in those already consuming sufficient fruit. There were no effects of descriptive norm information (P > .19).

CONCLUSIONS AND IMPLICATIONS

Information about outcomes was more persuasive than descriptive majority norm information. Effects were generally stronger in those already consuming sufficient fruit.

Social modeling of eating: a review of when and why social influence affects food intake and choice

A major determinant of human eating behavior is social modeling, whereby people use others' eating as a guide for what and how much to eat. We review the experimental studies that have independently manipulated the eating behavior of a social referent (either through a live confederate or remotely) and measured either food choice or intake. Sixty-nine eligible experiments (with over 5800 participants) were identified that were published between 1974 and 2014. Speaking to the robustness of the modeling phenomenon, 64 of these studies have found a statistically significant modeling effect, despite substantial diversity in methodology, food type, social context and participant demographics. In reviewing the key findings from these studies, we conclude that there is limited evidence for a moderating effect of hunger, personality, age, weight or the presence of others (i.e., where the confederate is live vs. remote). There is inconclusive evidence for whether sex, attention, impulsivity and eating goals moderate modeling, and for whether modeling of food choice is as strong as modeling of food intake. Effects with substantial evidence were: modeling is increased when individuals desire to affiliate with the model, or perceive themselves to be similar to the model; modeling is attenuated (but still significant) for healthy-snack foods and meals such as breakfast and lunch, and modeling is at least partially mediated through behavioral mimicry, which occurs without conscious awareness. We discuss evidence suggesting that modeling is motivated by goals of both affiliation and uncertainty-reduction, and outline how these might be theoretically integrated. Finally, we argue for the importance of taking modeling beyond the laboratory and bringing it to bear on the important societal challenges of obesity and disordered eating.

The proof is in the eating: subjective peer norms are associated with adolescents’ eating behaviour

Objective

To investigate associations of self-perceived eating-related peer norms (called ‘subjective peer norms’) with adolescents’ healthy eating intentions and intake of healthy and unhealthy food.

Design

Cross-sectional data were collected in a large international survey.

Setting

Two types of subjective peer norms were assessed: perceived peer encouragement of healthy eating and perceived peer discouragement of unhealthy eating. Outcome variables were healthy eating intentions, intake of healthy food (fruits and vegetables) and intake of unhealthy food (snacks and soft drinks).

Subjects

Over 2500 European (pre-)adolescents aged between 10 and 17 years participated.

Results

Subjective peer norms were associated with all three outcome variables. While both perceived encouragement of healthy eating and perceived discouragement of unhealthy eating were related to intentions, only peer encouragement of healthy eating was related to intakes of both healthy and unhealthy food.

Conclusions

Subjective peer norms play a role in adolescent eating behaviour and as such are an important target for health promotion. Addressing norms that encourage healthy eating may be more promising in changing behaviour than norms that discourage unhealthy eating.

How norms work: self-identification, attitude, and self-efficacy mediate the relation between descriptive social norms and vegetable intake

BACKGROUND

The current studies aim to show that descriptive social norms influence vegetable intake and to investigate three potentially underlying processes (self-identification, attitude, and self-efficacy).

METHODS

In two studies, descriptive social norms regarding vegetable intake were manipulated (majority vs. minority norm). Study 1 investigated both the relation between baseline vegetable intake and self-identification, attitude, and self-efficacy, as well as the effect of the norm manipulation on vegetable intake over a one-week period. Study 2 investigated potential mediation of the effect of the manipulation on vegetable intake intentions through self-identification, attitude, and self-efficacy.

RESULTS

Study 1 showed that the proposed mediators were related to a baseline measure of vegetable intake. Moreover, in participants identifying strongly with the norm referent group, majority norms led to higher vegetable consumption than minority norms. Study 2 showed that the direct effect of the social norm manipulation on vegetable intake intentions was partly mediated by self-identification, attitude, and self-efficacy.

CONCLUSIONS

These studies shed first light on processes underlying the effect of descriptive social norms on health behavior. A norm describing the behavior of a salient social group leads people to identify more with, have more positive attitudes toward, and feel more self-efficacious regarding that behavior.

Social norms and dietary behaviors among young adults

OBJECTIVE

To examine associations between young adults' dietary behaviors and perceived social norms for healthy eating.

METHODS

Cross-sectional survey of 1000 diverse college students. Associations between perceived behaviors of family, friends, and significant other and participants' dietary behaviors were examined using t-tests and linear regression.

RESULTS

Young adults consumed more fast food if they perceived that their family, friends, or significant other did so (p < .003). Sugar-sweetened beverage consumption was associated with perceived consumption by family and friends (p < .035). Fruit and vegetable consumption and dinner preparation were associated with perceived behavior of friends only (p < .001).

CONCLUSIONS

Young adults' dietary behaviors appear to reflect their perceptions of normative behavior, particularly among friends.

Social influences on eating: implications for nutritional interventions

We review recent research on the effect of social context on food intake and food choice and assess the implications for nutritional interventions. We focus on studies of modelling of eating behaviour and the impact of perceived eating norms on the amounts and types of food that individuals eat. We suggest that social context influences eating via multiple mechanisms, including identity signalling and self-presentation concerns. However, building on existing theoretical models, we propose that social factors may be particularly influential on nutrition because following the behaviour of others is adaptive and social norms inform individuals about behaviours that are likely to be optimal (‘if everyone else is doing it, I probably should be’). Guided by understanding of the potential underlying mechanisms, we discuss how social norms might be used to promote healthier nutrition.

Reducing high calorie snack food in young adults: a role for social norms and health based messages

Background

Consumption of high calorie junk foods has increased recently, especially among young adults and higher intake may cause weight gain. There is a need to develop public health approaches to motivate people to reduce their intake of junk food.

Objective

To assess the effect of health and social norm messages on high calorie snack food intake (a type of junk food) as a function of usual intake of junk food.

Design

In a between-subjects design, 129 young adults (45 men and 84 women, mean age = 22.4 years, SD = 4.5) were assigned to one of three conditions: 1) a social norm condition, in which participants saw a message about the junk food eating habits of others; 2) a health condition, in which participants saw a message outlining the health benefits of reducing junk food consumption and; 3) a control condition, in which participants saw a non-food related message. After exposure to the poster messages, participants consumed a snack and the choice and amount of snack food consumed was examined covertly. We also examined whether usual intake of junk food moderated the effect of message type on high calorie snack food intake.

Results

The amount of high calorie snack food consumed was significantly lower in both the health and the social norm message condition compared with the control message condition (36% and 28%, both p < 0.05). There was no significant difference in snack food or energy intake between the health and social norm message conditions. There was no evidence that the effect of the messages depended upon usual consumption of junk food.

Conclusions

Messages about the health effects of junk food and social normative messages about intake of junk food can motivate people to reduce their consumption of high calorie snack food.