Mimicry of food intake: the dynamic interplay between eating companions

Effects of bitten food images in marketing communications

Marketing communications (e.g., food packages, restaurant menus, coupons, social media posts) often include images of bitten and non-bitten (i.e., complete) foods. Taking an empirics first approach, the current research explores how and why these images influence consumers. A field study shows a higher redemption rate for discount coupons featuring a bitten (vs. non-bitten) food. However, a controlled online study fails to replicate this effect. Two additional preregistered studies shed light on the inconsistent results observed online and in the field by identifying two competing mechanisms catalyzed by bitten food images. Bitten food images lead to vicarious enticement, an automatic process in which a viewer makes sense of a bitten food image by picturing someone approaching and tasting the food, as well as emotional conflict (i.e., the simultaneous activation of positive and negative thoughts and feelings). While vicarious enticement has a positive impact on product responses, emotional conflict has a negative impact. The effect of bitten (vs. non-bitten) food images on product responses appears to depend on the strength of these two mechanisms in a given context. These findings yield insights for researchers examining visual characteristics of food images as well as advertisers designing marketing communications.

Mimicry in misophonia: A large-scale survey of prevalence and relationship with trigger sounds

BACKGROUND

Misophonia is often referred to as a disorder that is characterized by excessive negative emotional responses, including anger and anxiety, to "trigger sounds" which are typically day-to-day sounds, such as those generated from people eating, chewing, and breathing. Misophonia (literally "hatred of sounds") has commonly been understood within an auditory processing framework where sounds cause distress due to aberrant processing in the auditory and emotional systems of the brain. However, a recent proposal suggests that it is the perceived action (e.g., mouth movement in eating/chewing sounds as triggers) of the trigger person, and not the sounds per se, that drives the distress in misophonia. Since observation or listening to sounds of actions of others are known to prompt mimicry in perceivers, we hypothesized that mimicking the action of the trigger person may be prevalent in misophonia. Apart from a few case studies and anecdotal information, a relation between mimicking and misophonia has not been systematically evaluated.

METHOD

In this work, we addressed this limitation by collecting data on misophonia symptoms and mimicry behavior using online questionnaires from 676 participants.

RESULTS

Analysis of these data shows that (i) more than 45% of individuals with misophonia reported mimicry, indicating its wide prevalence, (ii) the tendency to mimic varies in direct proportion to misophonia severity, (iii) compared to other human and environmental sounds, trigger sounds of eating and chewing are more likely to trigger mimicking, and (iv) the act of mimicking provides some degree of relief from distress to people with misophonia.

CONCLUSION

This study shows prevalence of mimicry and its relation to misophonia severity and trigger types. The theoretical framework of misophonia needs to incorporate the phenomenon of mimicry and its effect on management of misophonia distress.

The Impact of Modifiable Preoral Factors on Swallowing and Nutritional Outcomes in Healthy Adults: A Scoping Review

PURPOSE

Swallowing has previously been characterized as consisting of four phases; however, it has become apparent that these four phases are not truly discrete and may be influenced by factors occurring prior to bolus entrance into the oral cavity (i.e., preoral factors). Still, the relationship between these factors and swallowing remains poorly understood. The aim of this review was to synthesize and characterize the literature pertaining to the influence of preoral factors on swallowing and nutritional outcomes in healthy individuals.

METHOD

We performed a scoping review, searching the databases of PubMed, CINAHL, Cochrane, and Scopus. Search terms included those related to swallowing, experience of preoral factors, and exclusionary terminology to reduce animal and pediatric literature. Our initial search revealed 5,560 unique articles, of which 153 met our inclusionary criteria and were accepted into the review.

RESULTS

Of the accepted articles, 78% were focused exclusively on nutritional outcomes, 17% were focused on both swallowing and nutritional outcomes, and 5% were focused on solely swallowing outcomes. Of the preoral factors examined, 99% were exteroceptive in nature (17% olfactory, 44% visual, 21% auditory, 7% tactile, 11% other), while 1% were proprioceptive in nature.

CONCLUSIONS

This review supports the influence of preoral factors on swallowing and nutritional outcomes. However, there is a large emphasis on the visual modality and on nutritional outcomes. Nearly none of the literature found in this review directly measured swallowing safety, efficiency, or physiology. Future work will benefit from a larger focus on proprioceptive preoral factors as they relate to swallowing outcomes.

Maternal adherence to healthy lifestyle and risk of depressive symptoms in the offspring: mediation by offspring lifestyle

BACKGROUND

Adherence to healthy lifestyles can be beneficial for depression among adults, but the intergenerational impact of maternal healthy lifestyles on offspring depressive symptoms is unknown.

METHODS

In total, 10 368 mothers in Nurses' Health Study II and 13 478 offspring in the Growing Up Today Study were paired. Maternal and offspring healthy lifestyles were defined as a composite score including a healthy diet, normal body mass index (BMI), never-smoking, light-to-moderate consumption of alcohol, and regular moderate-to-vigorous physical activity. Maternal lifestyles were assessed during their offspring's childhood. Offspring depressive symptoms were repeatedly assessed five times using the Center for Epidemiological Studies Depression Scale-10 (CESD-10); the offspring were between the ages of 14 and 30 when the first CESD-10 was assessed. Covariates included maternal variables (age at baseline, race/ethnicity, antidepressant use, pregnancy complications, etc.) and offspring age and sex.

RESULTS

Children of mothers with the healthiest lifestyle had significantly fewer depressive symptoms (a 0.30 lower CESD-10 score, 95% confidence interval (CI) 0.09-0.50) in comparison with children of mothers with the least healthy lifestyle. The association was only found significant in female offspring but not in males. For individual maternal lifestyle factors, a normal BMI, never-smoking, and adherence to regular physical activity were independently associated with fewer depressive symptoms among the offspring. The association between maternal healthy lifestyles and offspring depressive symptoms was mediated by offspring's healthy lifestyles (mediation effect: 53.2%, 95% CI 15.8-87.3).

CONCLUSIONS

Our finding indicates the potential mechanism of intergenerational transmission of healthy lifestyles to reduce the risk of depressive symptoms in offspring.

Factors associated with eating rate: a systematic review and narrative synthesis informed by socio-ecological model

Accumulating evidence shows associations between rapid eating and overweight. Modifying eating rate might be a potential weight management strategy without imposing additional dietary restrictions. A comprehensive understanding of factors associated with eating speed will help with designing effective interventions. The aim of this review was to synthesise the current state of knowledge on the factors associated with eating rate. The socio-ecological model (SEM) was utilised to scaffold the identified factors. A comprehensive literature search of eleven databases was conducted to identify factors associated with eating rate. The 104 studies that met the inclusion criteria were heterogeneous in design and methods of eating rate measurement. We identified thirty-nine factors that were independently linked to eating speed and mapped them onto the individual, social and environmental levels of the SEM. The majority of the reported factors pertained to the individual characteristics (n = 20) including demographics, cognitive/psychological factors and habitual food oral processing behaviours. Social factors (n = 11) included eating companions, social and cultural norms, and family structure. Environmental factors (n = 8) included food texture and presentation, methods of consumption or background sounds. Measures of body weight, food form and characteristics, food oral processing behaviours and gender, age and ethnicity were the most researched and consistent factors associated with eating rate. A number of other novel and underresearched factors emerged, but these require replication and further research. We highlight directions for further research in this space and potential evidence-based candidates for interventions targeting eating rate.

Effects of Meal Similarity on Interpersonal Synchronization in Three-Party Remote Dining

In recent years, online commensality, such as remote dining, has become a way to connect people in different places. In remote dining, people have drinks, snacks, or meals while chatting with each other via video calls and seek connectedness and belonging. However, many people feel that there is a gap between real-life and digital co-eating and that interaction in current remote dining fails to satisfy the need for companionship. Unlike real-life co-eating, in remote dining, one's meal may not be similar to that of a partner's because people usually prepare their own food separately. In this study, we focused on the effects of meal similarity on interpersonal synchronization and subjective feelings. We conducted a laboratory-based remote dining experiment and video analysis to investigate whether eating similar meals in remote conditions has any effect on eating behavior and to explore the relationship between meal similarity, interpersonal synchronization, and subjective feelings. The results showed that participants ate at a faster pace and conducted eating actions more frequently. They were more synchronized with their partners, and the feeling of togetherness was stronger. Thus, we suggest that preparing similar meals or ordering the same dishes can enhance the remote dining experience.

Behavioral mimicry of eating in mice

Nonconscious behavioral mimicry is prevalent in humans and highly social animals who imitate the behaviors of others without awareness. Previous studies indicated people tended to match their amount of eating to that of their eating companions due to behavioral mimicry, however whether such phenomena were existed in rodents is still unknown. Developing a behavioral paradigm would be helpful to better understand the molecular and circuit mechanisms underlying behavioral mimicry. In this study, we examined behavioral mimicry of eating in C57BL/6J mice which had strong sociality and were widely used as animal model in researches. We set up an eating monitoring platform, and this platform could record the data of mice eating behavior in real time. We further examined the behavioral mimicry of eating in mice, and found that the mice observing eating behavior of food-restricted mice would consume more food than control mice, and visual cue with eating behavior was sufficient to increased food consumption in mice. Our study indicated behavioral mimicry of eating was existed in mice and provided a mouse model for future studies on the mechanism of behavioral mimicry of eating.

Content Validation of a Chrononutrition Questionnaire for the General and Shift Work Populations: A Delphi Study

Unusual meal timing has been associated with a higher prevalence of chronic disease. Those at greater risk include shift workers and evening chronotypes. This study aimed to validate the content of a Chrononutrition Questionnaire for shift and non-shift workers to identify temporal patterns of eating in relation to chronotype. Content validity was determined using a Delphi study of three rounds. Experts rated the relevance of, and provided feedback on, 46 items across seven outcomes: meal regularity, times of first eating occasion, last eating occasion, largest meal, main meals/snacks, wake, and sleep, which were edited in response. Items with greater than 70% consensus of relevance were accepted. Rounds one, two, and three had 28, 26, and 24 experts, respectively. Across three rounds, no outcomes were irrelevant, but seven were merged into three for ease of usage, and two sections were added for experts to rate and comment on. In the final round, all but one of 29 items achieved greater than 70% consensus of relevance with no further changes. The Chrononutrition Questionnaire was deemed relevant to experts in circadian biology and chrononutrition, and could represent a convenient tool to assess temporal patterns of eating in relation to chronotype in future studies.

The Motor Basis for Misophonia

Misophonia is a common disorder characterized by the experience of strong negative emotions of anger and anxiety in response to certain everyday sounds, such as those generated by other people eating, drinking, and breathing. The commonplace nature of these "trigger" sounds makes misophonia a devastating disorder for sufferers and their families. How such innocuous sounds trigger this response is unknown. Since most trigger sounds are generated by orofacial movements (e.g., chewing) in others, we hypothesized that the mirror neuron system related to orofacial movements could underlie misophonia. We analyzed resting state fMRI (rs-fMRI) connectivity (N = 33, 16 females) and sound-evoked fMRI responses (N = 42, 29 females) in misophonia sufferers and controls. We demonstrate that, compared with controls, the misophonia group show no difference in auditory cortex responses to trigger sounds, but do show: (1) stronger rs-fMRI connectivity between both auditory and visual cortex and the ventral premotor cortex responsible for orofacial movements; (2) stronger functional connectivity between the auditory cortex and orofacial motor area during sound perception in general; and (3) stronger activation of the orofacial motor area, specifically, in response to trigger sounds. Our results support a model of misophonia based on "hyper-mirroring" of the orofacial actions of others with sounds being the "medium" via which action of others is excessively mirrored. Misophonia is therefore not an abreaction to sounds, per se, but a manifestation of activity in parts of the motor system involved in producing those sounds. This new framework to understand misophonia can explain behavioral and emotional responses and has important consequences for devising effective therapies.SIGNIFICANCE STATEMENT Conventionally, misophonia, literally "hatred of sounds" has been considered as a disorder of sound emotion processing, in which "simple" eating and chewing sounds produced by others cause negative emotional responses. Our data provide an alternative but complementary perspective on misophonia that emphasizes the action of the trigger-person rather than the sounds which are a byproduct of that action. Sounds, in this new perspective, are only a "medium" via which action of the triggering-person is mirrored onto the listener. This change in perspective has important consequences for devising therapies and treatment methods for misophonia. It suggests that, instead of focusing on sounds, which many existing therapies do, effective therapies should target the brain representation of movement.

Social modulation of ageing: mechanisms, ecology, evolution

Human life expectancy increases, but the disease-free part of lifespan (healthspan) and the quality of life in old people may not show the same development. The situation poses considerable challenges to healthcare systems and economies, and calls for new strategies to increase healthspan and for sustainable future approaches to elder care. This call has motivated innovative research on the role of social relationships during ageing. Correlative data from clinical surveys indicate that social contact promotes healthy ageing, and it is time to reveal the causal mechanisms through experimental research. The fruit fly Drosophila melanogaster is a prolific model animal, but insects with more developed social behaviour can be equally instrumental for this research. Here, we discuss the role of social contact in ageing, and identify lines of study where diverse insect models can help uncover the mechanisms that are involved. This article is part of the theme issue 'Ageing and sociality: why, when and how does sociality change ageing patterns?'

Social Modeling and Eating Behavior-A Narrative Review

Social modeling of eating is the adjustment of the amount of food eaten to the intake of the accompanying person. In this paper we provide a narrative review of literature on social modeling of eating with a particular focus on recent studies. Firstly, we describe the structure of a typical modeling experiment. Secondly, we present a variety of research in this field: experiments with various types of confederates, experiments aimed at the evaluation of the influence of gender, partner’s body weight, type of food, hunger, personal characteristics, etc. Thirdly, we present practical implications of this knowledge. The common conclusion is that social modeling of eating occurs in different situations and consumption is adapted to the standards established by the eating partner, but is not their direct reflection. Social influence of eating is not restricted to "artificial" laboratory situations; social modeling and social norms manipulations may be used to change people’s dietary practices, especially in children and young adults. Within the home environment parental modeling has been shown to promote children’s snacking and fruit and vegetable consumption. Social modeling may be used in nutrition interventions aimed at the improvement of children’s diet and in obesity prevention programs.

Social modeling of food choices in real life conditions concerns specific food categories

The social context of eating has a profound effect on consumption choices. Social modeling, that involves using others' behavior as a guide for appropriate consumption, has been well documented for food intake, but less is known about social modeling of food choices. Moreover, social modeling has mainly been studied in laboratory settings. We conducted an observational study in a self-service canteen to examine whether the food choices of an individual were influenced by the choice of the person ahead in the queue. We recorded food choices of 546 individuals (333 men and 211 women) and those of the person in front of them in the queue along a linear buffet. Starters were sub-categorized into salads, mixed starters (e.g. avocado shrimp mayonnaise), and cold meat starters, and desserts were sub-categorized into fruits, dairy products and pastries. There was a significantly higher probability of taking a starter in general (OR = 1.65, IC = 1.06-2.57, p = 0.03), a salad (OR = 1.78, CI = 1.08-2.93, p = 0.02), a mixed starter (OR = 2.98, CI = 1.42-6.05, p < 0.01), but not a cold meat, if the person ahead in the queue also took one compared to when the person ahead did not take one. No significant modelling was found for desserts which may be because almost all participants took a dessert. These results highlight that social modeling influences food choices, and that this phenomenon can be observed in a real life setting. These data also suggest that some food categories, such as starters, could be more susceptible to social modeling than are others. Finally, we observed modeling both between familiar and unfamiliar participants, which suggests that social norms could be used to promote healthier eating in a range of settings including friendship groups.

Self-categorization as a basis of behavioural mimicry: Experiments in The Hive

INTRODUCTION

Do we always do what others do, and, if not, when and under what conditions do we do so? In this paper we test the hypothesis that mimicry is moderated by the mere knowledge of whether the source is a member of the same social category as ourselves.

METHODS

We investigated group influence on mimicry using three tasks on a software platform which interfaces with mobile computing devices to allow the controlled study of collective behaviour in an everyday environment.

RESULTS

Overall, participants (N = 965) were influenced by the movements of confederates (represented as dots on a screen) who belonged to their own category in both purposive and incidental tasks.

CONCLUSION

Our results are compatible with collective level explanations of social influence premised on shared social identification. This includes both a heuristic of unintended mimicry (the acts of group members are diagnostic of how one should act), and communication of affiliation (based on a desire to make one's group cohesive). The results are incompatible with traditional 'contagion' accounts which suggest mimicry is automatic and inevitable. The results have practical implications for designing behavioural interventions which can harness the power of copying behaviour, for example in emergency evacuations.

Behavioral Mimicry as a Strategy to Increase Drinking Behaviors in Older Adults

Purpose Individuals with dysphagia, particularly in the presence of dementia, are at high risk for decreased nutrition and hydration. Unfortunately, current treatment options are not without limitations and often ignore the crucial social aspects of mealtimes. The aim of this exploratory, proof-of-concept study was to examine whether the social phenomenon of nonconscious behavioral mimicry can increase drinking behaviors in healthy older adults. Method Forty-two older adults (M _age = 68.26 years, SD = 6.49) participated. Participants and a member of the research team posing as another participant (a confederate) took turns describing two series of pictures, while, unbeknownst to the participants, the confederate either frequently drank from a cup of water or touched the cup. The primary outcome measures (number of drinks per minute, number of cup touches per minute, percentage of time spent drinking, and percentage of time spent touching the cup) were coded and analyzed across both the confederate drinking and cup-touching conditions. Results Participants drank more frequently and spent more task time drinking during the confederate drinking condition as compared to the cup-touching condition. There was significant variability in drinking patterns across participants, with some only drinking when they were not engaged in the picture description task. Conclusions Behavioral mimicry may increase drinking behaviors in healthy older adults, although the effect may not be as robust among certain subsets of individuals. Clinically, mimicry may hold potential as a powerful, noninvasive supplemental mealtime strategy for increasing intake in those who are most at risk for malnutrition.

The Snacking Chameleon: Psychological Proximity Increases Imitation of Food Intake Independently of Brand Choice

Observing other people snacking can affect one’s own consumption behavior. The present experiment tested whether temporal distance moderates imitation of brand choice and the number of snacks consumed. Based on previous research demonstrating that psychological distance (e.g., temporal or spatial distance) reduces imitation of movements, we hypothesized that participants would imitate the amount of food intake to a lesser degree when they temporally distance themselves from a model person. To test this idea, participants (n = 113) were asked to imagine their life either the next day (proximal condition) or in one year (distant condition). Next, participants watched a video clip depicting a model person who chose one of two brands of pretzels and ate either plenty or just a few of the pretzels. Then, participants chose one of the two brands of pretzels, served themselves as many of the pretzels as they liked, and ate them while filling in a tasting questionnaire. As expected, participants primed with proximity imitated snack intake more than participants primed with distance. The brand choice was not affected by self-distancing. Implications for snacking behavior are discussed.

Sensing eating mimicry among family members

Family relationships influence eating behavior and health outcomes (e.g., obesity). Because eating is often habitual (i.e., automatically driven by external cues), unconscious behavioral mimicry may be a key interpersonal influence mechanism for eating within families. This pilot study extends existing literature on eating mimicry by examining whether multiple family members mimicked each other's bites during natural meals. Thirty-three participants from 10 families were videotaped while eating an unstructured family meal in a kitchen lab setting. Videotapes were coded for participants' bite occurrences and times. We tested whether the likelihood of a participant taking a bite increased when s/he was externally cued by a family eating partner who had recently taken a bite (i.e., bite mimicry). A paired-sample t-test indicated that participants had a significantly faster eating rate within the 5 s following a bite by their eating partner, compared to their bite rate at other times (t = 7.32, p < .0001). Nonparametric permutation testing identified five of 78 dyads in which there was significant evidence of eating mimicry; and 19 of 78 dyads that had p values < .1. This pilot study provides preliminary evidence that suggests eating mimicry may occur among a subset of family members, and that there may be types of family ties more prone to this type of interpersonal influence during meals.

Computational Commensality: From Theories to Computational Models for Social Food Preparation and Consumption in HCI

Food and eating are inherently social activities taking place, for example, around the dining table at home, in restaurants, or in public spaces. Enjoying eating with others, often referred to as “commensality,” positively affects mealtime in terms of, among other factors, food intake, food choice, and food satisfaction. In this paper we discuss the concept of “Computational Commensality,” that is, technology which computationally addresses various social aspects of food and eating. In the past few years, Human-Computer Interaction started to address how interactive technologies can improve mealtimes. However, the main focus has been made so far on improving the individual's experience, rather than considering the inherently social nature of food consumption. In this survey, we first present research from the field of social psychology on the social relevance of Food- and Eating-related Activities (F&EA). Then, we review existing computational models and technologies that can contribute, in the near future, to achieving Computational Commensality. We also discuss the related research challenges and indicate future applications of such new technology that can potentially improve F&EA from the commensality perspective.

Digital Commensality: Eating and Drinking in the Company of Technology

Commensality is a key aspect of social dining. However, previous research has identified a number of pros and cons associated with the incorporation of digital technology into eating and drinking episodes. For instance, those who are distracted by digital technology may eat/drink more (that is, they may overconsume) as a result of their failure to attend to the food-related sensations that are thought to cue the termination of eating. Similarly, it has often been suggested that the use of mobile devices at mealtimes can disrupt the more commensal aspects of dining/drinking (at least among those who are physically present together). At the same time, however, looking to the future, it seems clear that digital technologies also hold the promise of delivering opportunities for enhanced multisensory experiential dining. For instance, they might be used to match the auditory, visual, or audiovisual entertainment to the eating/drinking episode (e.g., think only about watching a Bollywood movie while eating a home-delivery Indian meal, say). Indeed, given the growing societal problems associated with people dining by themselves, there are a number of routes by which digital technologies may increasingly help to connect the solo diner with physically co-located, remote, or even virtual dining partners. In this review of the literature, our focus is specifically on the role of technology in inhibiting/facilitating the more pleasurable social aspects of dining, what one might call "digital commensality." The focus is primarily on Westernized adults with reasonable access to, and familiarity with, digital technologies.

Personal Network Characteristics as Predictors of Change in Obesity Risk Behaviors in Early Adolescence

The potential for peers to influence obesity risk behavior increases in adolescence, yet there are knowledge gaps of how behaviors are modified in response to peers over time. This study examined how personal friendship network characteristics were associated with obesity-related behaviors from late childhood to early adolescence. Two waves of friendship, physical activity, screen time, and dietary recall data were collected from 11- to 13-year-old students (99% retention) in Australia (n = 308) over a five- to eight-month period. Regression models identified friendship network characteristics that predicted later health behaviors which varied by gender and behavior type, such as the number of friends positively associated with physical activity intensity (males) and screen time (females). The need for considering context to influence behavior change is discussed.

The rippling dynamics of valenced messages in naturalistic youth chat

Even though human behavior is largely driven by real-time feedback from others, this social complexity is underrepresented in psychological theory, largely because it is so difficult to isolate. In this work, we performed a quasi-experimental analysis of hundreds of millions of chat room messages between young people. This allowed us to reconstruct how-and on what timeline-the valence of one message affects the valence of subsequent messages by others. For the highly emotionally valenced chat messages that we focused on, we found that these messages elicited a general increase of 0.1 to 0.4 messages per minute. This influence started 2 s after the original message and continued out to 60 s. Expanding our focus to include feedback loops-the way a speaker's chat comes back to affect him or her-we found that the stimulating effects of these same chat events started rippling back from others 8 s after the original message, to cause an increase in the speaker's chat that persisted for up to 8 min. This feedback accounted for at least 1% of the bulk of chat. Additionally, a message's valence affects its dynamics, with negative events feeding back more slowly and continuing to affect the speaker longer. By reconstructing the second-by-second dynamics of many psychosocial processes in aggregate, we captured the timescales at which they collectively ripple through a social system to drive system-level outcomes.

Social modeling of eating mediated by mirror neuron activity: A causal model moderated by frontal asymmetry and BMI

The social modeling of eating effect refers to the consistently demonstrated phenomenon that individuals tend to match their quantity of food intake to their eating companion. The current study sought to explore whether activity within the mirror neuron system (MNS) mediates the social modeling of eating effect as a function of EEG frontal asymmetry and body mass index (BMI). Under the guise of rating empathy, 93 female undergraduates viewed a female video confederate "incidentally" consume either a low or high intake of chips while electroencephalogram (EEG) activity was recorded. Subsequent ad libitum chip consumption was quantified. A first- and second-stage dual moderation model revealed that frontal asymmetry and BMI moderated an indirect effect of model consumption on participants' food consumption as mediated by MNS activity at electrode site C3, a₃b₃=-0.718, SE=0.365, 95% CI [-1.632, -0.161]. Left frontal asymmetry was associated with greater mu activity and a positive association between model and participant chip consumption, while right frontal asymmetry was associated with less mu activity and a negative association between model and participant consumption. Across all levels of frontal asymmetry, the effect was only significant among those with a BMI at the 50th percentile or lower. Thus, among leaner individuals, the MNS was demonstrated to mediate social modeling of eating, as moderated by frontal asymmetry. These findings are integrated within the normative account of social modeling of eating. It is proposed that the normative framework may benefit from consideration of both conscious and unconscious operation of intake norms.

Goal-Directed Drinking Behaviors Can Be Modified Through Behavioral Mimicry

PURPOSE

This study tested whether behavioral mimicry can alter drinking behavior. It was hypothesized that participants would increase drinking behaviors given increased confederate drinking but not cup touching.

METHODS

Nineteen healthy adults (Mage = 20.32 years) completed 2 picture description tasks; during 1 task, a confederate frequently sipped water (complete drinking gesture), and during the other, the confederate touched her cup but did not drink (partial gesture). Outcome measures included number of drinks per minute, number of cup touches per minute, percentage of time spent drinking, and percentage of time spent touching the cup.

RESULTS

Participants spent more time drinking and had an increased drinking rate during the drinking condition versus the cup-touching condition. For a majority of participants, drinking rate increased during the drinking condition versus baseline. Drinking, but not cup touching, rate also increased given increased confederate cup touching for many.

CONCLUSIONS

Mimicry likely contributes to social modeling of drinking behaviors. This effect appears more robust given a complete target gesture (full drink); however, a partial goal-directed drinking gesture may also yield a mimicked response. Beyond the theoretical implications, these results provide directions for research investigating more naturalistic mechanisms for increasing dietary intake in various patient populations (e.g., individuals with dysphagia).

Portion size tells who I am, food type tells who you are: Specific functions of amount and type of food in same- and opposite-sex dyadic eating contexts

Previous research has shown that women eating small portions of food (vs. eating big portions) are perceived as more feminine, whereas men eating large portions are perceived as more masculine. The specific type of food items have also been shown to carry connotations for gender stereotyping. In addition, matching the co-eater's food quantity is also a means to ingratiate him or her. Thus, a potential motivational conflict between gender identity expression and ingratiation arises when people eat in opposite-sex dyads. Scholars have, thus far, focused their attention on one of these two dimensions at a time, and rarely in relation to the co-eaters' sex. The present study investigated, through a restaurant scenario, the way in which women and men, when asked to imagine having lunch in dyads, combine food choice and quantity regulation as a function of the co-eater's sex. Results showed that participants use the quantity dimension to communicate gender identity, and the food type dimension to ingratiate the co-eater's preferences by matching her/his presumed choice, following gender-based stereotypes about food. In opposite-sex dyads, dishes that incorporate the two dimensions were chosen above the expected frequency.

Environmental Strategies to Promote Food Intake in Older Adults: A Narrative Review

Aging is often accompanied by lower intakes of food energy and consequent negative effects on health. To some extent this is due to declines in physiological ability, including the sensory responsiveness to regulate food intake. Fortunately, environmental factors may still influence food intake in older adults. Factors such as social facilitation, modeling, and nutrition knowledge and skills have been shown to stimulate their food intake. While environmental factors such as the eating location, portion size, food presentation, and labeling are known to influence eating behavior, their effectiveness in stimulating food intake in older persons is not well delineated. It is suggested that improving the environmental stimuli that promote food intake is a viable strategy to overcome age-related declines in nutrient intakes. This strategy is so promising that further research is warranted.

Cognitive mechanisms for responding to mimicry from others

Compared to our understanding of neurocognitive processes involved producing mimicry, the downstream consequences of being mimicked are less clear. A wide variety of positive consequences of mimicry, such as liking and helping, have been reported in behavioural research. However, an in-depth review suggests the link from mimicry to liking and other positive outcomes may be fragile. Positive responses to mimicry can break down due to individual factors and social situations where mimicry may be unexpected. It remains unclear how the complex behavioural effects of mimicry relate to neural systems which respond to being mimicked. Mimicry activates regions associated with mirror properties, self-other processing and reward. In this review, we outline three potential models linking these regions with cognitive consequences of being mimicked. The models suggest that positive downstream consequences of mimicry may depend upon self-other overlap, detection of contingency or low prediction error. Finally, we highlight limitations with traditional research designs and suggest alternative methods for achieving highly ecological validity and experimental control. We also highlight unanswered questions which may guide future research.

The Possible Antecedents and Consequences of Matching of Food Intake: Examining the Role of Trait Self-Esteem and Interpersonal Closeness

Although there is evidence that people tend to match their intake to that of others, less is known about the motives underlying this effect. The current study, therefore, examined the relationship between self-esteem, a specific factor that has been related to the likelihood of social matching. Further, we examined the effects of food matching on interpersonal closeness among eating companions. The sample included 89 female dyads. All dyads had free access to palatable snack food during a 15 min interaction. For each dyad the matching score was calculated, as well as both individual's trait self-esteem scores and interpersonal closeness with their eating partner. The overall degree of matching within dyads was high, replicating the findings of previous research. No relationship, however, was found between trait self-esteem and the degree of matching. Furthermore, there was no effect of matching on perceived interpersonal closeness with or liking of the other person. These results suggest that self-esteem might not be a robust predictor of matching and that matching of food intake may not result in increased perceived interpersonal closeness or liking among eating partners.

Interoceptive dysfunction: toward an integrated framework for understanding somatic and affective disturbance in depression

Depression is characterized by disturbed sleep and eating, a variety of other nonspecific somatic symptoms, and significant somatic comorbidities. Why there is such close association between cognitive and somatic dysfunction in depression is nonetheless poorly understood. An explosion of research in the area of interoception-the perception and interpretation of bodily signals-over the last decade nonetheless holds promise for illuminating what have until now been obscure links between the social, cognitive-affective, and somatic features of depression. This article reviews rapidly accumulating evidence that both somatic signaling and interoception are frequently altered in depression. This includes comparative studies showing vagus-mediated effects on depression-like behaviors in rodent models as well as studies in humans indicating both dysfunction in the neural substrates for interoception (e.g., vagus, insula, anterior cingulate cortex) and reduced sensitivity to bodily stimuli in depression. An integrative framework for organizing and interpreting this evidence is put forward which incorporates (a) multiple potential pathways to interoceptive dysfunction; (b) interaction with individual, gender, and cultural differences in interoception; and (c) a developmental psychobiological systems perspective, emphasizing likely differential susceptibility to somatic and interoceptive dysfunction across the lifespan. Combined with current theory and evidence, it is suggested that core symptoms of depression (e.g., anhedonia, social deficits) may be products of disturbed interoceptive-exteroceptive integration. More research is nonetheless needed to fully elucidate the relationship between mind, body, and social context in depression.

Awareness of social influence on food intake. An analysis of two experimental studies

There is consistent evidence that the amount of food we consume can be influenced by the eating behaviour of other people. Some previous experimental studies reported that consumers are unaware of this influence on their behaviour. The present research tested whether people may be more aware of social influence on their eating than previously assumed. In two studies, participants (total n = 160) were exposed to information about the amount of snack food other people had been eating shortly before being served the same snack food and eating as much as they liked. After this, participants responded to questions regarding whether they thought their food intake had been socially influenced, and reported the reasons why they believed they had or had not been influenced. Of the 160 participants, 34% reported that they had been influenced, 10% were unsure and 56% reported they had not been influenced. Crucially, participants' reports of social influence appeared to be accurate; the food intake of participants reporting social influence was significantly affected by the amount of food other people had been eating, whereas the food intake of participants denying social influence was unaffected. Individuals may be more aware of the effect that social influence has on their eating behaviour than previously assumed. Further work is needed to identify the factors which determine whether people are susceptible to social influence on eating behaviour.

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.

Looking while eating: the importance of social context to social attention

Recent studies have found that participants consistently look less at social stimuli in live situations than expected from conventional laboratory experiments, raising questions as to the cause for this discrepancy and concerns about the validity of typical studies. We tested the possibility that it is the consequences of a potential social interaction that dictates one's looking behaviour. By placing participants in a situation where the social consequences of interacting are congruent with social norms (sharing a meal), we find an increased preference for participants to look at each other. Dyads who were particularly interactive also looked more at the other person than dyads who did not interact. Recent landmark studies have shown that in real world settings people avoid looking at strangers, but we show that in a situation with a different social context the opposite holds true.

Food for love: the role of food offering in empathic emotion regulation

The present article examines the interpersonal and intrapersonal antecedents and consequences of food offering. Food offering is one of the earliest biobehavioral regulatory interactions between parent and child. It ensures survival of the child who is fully dependent on food provision by others. The quality of these early interactions influences how people respond to situations later in life, and food offering in particular may be closely related to emotion regulation throughout the lifespan. While research has examined other forms of emotion regulation, and food consumption has been studied from an intrapersonal perspective, we know little about the interpersonal effects of food offering. After reviewing literature from a wide range of disciplines, we propose that one mechanism underlying these effects is empathic emotion regulation (EER). We conceptualize EER as an interpersonal regulation system in which an empathic response to another person’s emotional state aims to regulate both emotion within the provider and across interaction partners. We suggest that the offer of food by an empathic provider is motivated by the emotional state of one’s interaction partner (recipient). By offering food, the provider not only aims to attenuate the recipient’s negative affect but also her own. Food offering thereby becomes a means to increase positive affect for both recipient and – when the offer has the desired effect – provider. We further propose that the sharing of food resources as well as the use of food as a support behavior increases interpersonal closeness. Finally, we frame the process of food offering within a developmental perspective. If the regulatory success of food offering becomes a replacement for other support behaviors, children will learn from an early age to use food as a primary means to soothe self and others, possibly resulting in eating disorders and a restricted range of coping behavior.

Imitation of snack food intake among normal-weight and overweight children

This study investigated whether social modeling of palatable food intake might partially be explained by the direct imitation of a peer reaching for snack food and further, assessed the role of the children's own weight status on their likelihood of imitation during the social interaction. Real-time observations during a 10-min play situation in which 68 participants (27.9% overweight) interacted with normal-weight confederates (instructed peers) were conducted. Children's imitated and non-imitated responses to the confederate's food picking movements were compared using a paired sample t-test. In addition, the pattern of likelihood of imitation was tested using multilevel proportional hazard models in a survival analysis framework. Children were more likely to eat after observing a peer reaching for snack food than without such a cue [t₍₆₇₎ = 5.69, P < 0.0001]. Moreover, findings suggest that children may display different imitation responses during a social interaction based on their weight status (HR = 2.6, P = 0.03, 95% CI = 1.09–6.20). Overweight children were almost twice as likely to imitate, whereas normal-weight children had a smaller chance to imitate at the end of the interaction. Further, the mean difference in the likelihood of imitation suggest that overweight children might be less likely to imitate in the beginning of the interaction than normal-weight children. The findings provide preliminary evidence that children's imitation food picking movements may partly contribute to social modeling effects on palatable food intake. That is, a peer reaching for food is likely to trigger children's snack intake. However, the influence of others on food intake is a complex process that might be explained by different theoretical perspectives.

Social models provide a norm of appropriate food intake for young women

It is often assumed that social models influence people’s eating behavior by providing a norm of appropriate food intake, but this hypothesis has not been directly tested. In three experiments, female participants were exposed to a low-intake model, a high-intake model, or no model (control condition). Experiments 1 and 2 used a remote-confederate manipulation and were conducted in the context of a cookie taste test. Experiment 3 used a live confederate and was conducted in the context of a task during which participants were given incidental access to food. Participants also rated the extent to which their food intake was influenced by a variety of factors (e.g., hunger, taste, how much others ate). In all three experiments, participants in the low-intake conditions ate less than did participants in the high-intake conditions, and also reported a lower perceived norm of appropriate intake. Furthermore, perceived norms of appropriate intake mediated the effects of the social model on participants’ food intake. Despite the observed effects of the social models, participants were much more likely to indicate that their food intake was influenced by taste and hunger than by the behavior of the social models. Thus, social models appear to influence food intake by providing a norm of appropriate eating behavior, but people may be unaware of the influence of a social model on their behavior.

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.