C. Peter Herman's research while affiliated with University of Toronto and other places

Publications (214)

Article
Social modeling is a powerful influence on people's food intake: When there is a clear and consistent norm, people eat more when eating with someone who eats a lot and eat less when eating with someone who eats only a little. In three studies, the present research examined how clear versus ambiguous social-normative information influences the model...
Article
Defining and measuring such qualities as restrained eating or dieting may require more than simply administering questionnaires and assuming that we are identifying the population that we wish to study. Different questionnaires may identify different types of restrained eaters, and even deciding what restrained eating consists of is a complicated e...
Article
The Theory of Normal Eating suggests that how much others eat sets an upper limit for how much it is appropriate to eat. This study tested the hypothesis that restrained eaters, who typically eat less than they want to, would be more responsive to a high-intake norm than would unrestrained eaters. Data were combined from 8 experimental studies (tot...
Article
“Overeating” is a significant public health concern, but little is known about how lay people conceptualize overeating. This study explored participants' conceptions of overeating. Participants were 175 university students and 296 community members (56% women) who were asked to rate the extent to which several statements reflected the concept of “o...
Chapter
Modeling of food intake refers to the tendency for people to adjust the amount of food they eat to approximate the amount eaten by their eating companion. People eat more when eating with someone who eats a lot, and they eat less when eating with someone who eat very little. In this chapter, we summarize the research documenting the modeling effect...
Chapter
People eat differently when eating with another person than they do when eating alone. Specifically, we tend to eat similarly to those with whom we eat, sticking more closely to eating norms, and mimicking what and how much our eating companions consume. Eating together and eating according to similar cultural norms or rules has been shown to be a...
Chapter
What we choose to eat, and how much we eat, are powerfully affected by the behavior of other people, as we have seen. To a large extent, we base our food choices on what others choose, and we tend to eat more or less depending on whether our eating companions eat more or less (modeling). We also choose to eat particular foods so as to make a positi...
Chapter
Even before deciding how much to eat, people usually have already chosen what they are going to eat. Food choice and food preferences are determined in part by biological factors, but social factors play an important role. Studies of modeling show that young children and young adults imitate the food choices of others. This is true when the options...
Chapter
In the previous chapter, we considered the idea that the amount of food that a person eats is often used by others as a basis for inferences about that person; we referred to these inferences as “consumption stereotypes.”
Chapter
Before we examine in detail some of the extensive research on social influences on eating, it’s important to discuss two general kinds of concerns about research: methodological concerns and ethical concerns. Both limit what researchers do while conducting research. Methodologically speaking, for research to tell us anything useful, it must be desi...
Chapter
Research on modeling, consumption stereotypes, and impression management is consistent with our theory emphasizing norms of appropriateness. In this chapter we turn to some bodies of research that are less obviously related to norms of appropriateness; however, we believe they are related. The basic idea is that people can figure out what and how m...
Chapter
A large literature shows that people compare themselves to others on a wide variety of dimensions; this is called social comparison. Such comparisons to other people can provide useful guides for our behavior, and they may also have emotional consequences, affecting our self-esteem and happiness. We compare ourselves to others with respect to our f...
Chapter
People form impressions of others based on how much those others eat—we refer to these judgments as “consumptions stereotypes”. For example, people who eat large amounts of food are often viewed as more masculine and less feminine than are people who eat small amounts of food. Given the existence of these consumption stereotypes, people can use the...
Chapter
Social factors play a critical role in determining people’s food intake, but are they aware of the influence that these social factors have? In this chapter, we review evidence related to three key questions about awareness: (1) Do people notice how much others eat? (2) Are people aware of how much they eat in social situations? (3) Are people awar...
Chapter
Overeating can refer to eating more than we had intended to eat, eating more than our eating companions eat, or eating more than norms dictate is an appropriate amount. The act of overeating, however it is defined in a particular situation, has effects on people. These effects may be cognitive (i.e., related to our thoughts), emotional, or behavior...
Chapter
At the end of the Introductory chapter, we alluded to our Theory of Normal Eating. In this chapter, we will flesh out that theory and elaborate on some of the ideas we presented earlier.
Article
The present study aimed to investigate the effect of the spatial positioning of a healthy food cue in the context of unhealthy food cues on subsequent food choice. Undergraduate women (N = 143) were asked to choose a food from a pictorial-style menu that presented a salad and three unhealthier food options in a horizontal line. The position of the...
Article
The contemporary food-rich environment has been consistently linked to unhealthy eating. Emerging research suggests that changing the presentation context of unhealthy foods by introducing a subtle nudge in the form of a healthy food cue may promote healthier dietary choices. This study investigated the effect of the timing of a healthy food cue (b...
Book
This book examines how the social environment affects food choices and intake, and documents the extent to which people are unaware of the significant impact of social factors on their eating. The authors take a unique approach to studying eating behaviors in ordinary circumstances, presenting a theory of normal eating that highlights social influe...
Article
Full-text available
Objective: Recent work has shown that exposure to social norm messages may enhance the consumption of vegetables. However, the majority of this work has been conducted in laboratories, often with student populations. Little is known about whether this approach can be successfully used in other contexts. In this study, a poster featuring a message...
Article
Normative eating cues (portion size, social factors) have a powerful impact on people's food intake, but people often fail to acknowledge the influence of these cues, instead explaining their food intake in terms of internal (hunger) or sensory (taste) cues. This study examined whether the same biases apply when making predictions about how much fo...
Article
Full-text available
People eat more when they eat in groups. Various explanations have been offered for this “social facilitation” of eating. We consider these explanations and find most of them wanting, especially insofar as they do not take into account the increased per capita provision of food when people eat together. We suggest that people often prefer to eat in...
Article
Full-text available
Purpose of review: The purposes of the present review are to organize the recent literature on the effects of food cues on restrained and unrestrained eaters and to determine current directions in such work. Recent findings: Research over the last several years involves both replicating the work showing that restrained eaters respond to attracti...
Article
Objective: We examined whether people’s attributions for their eating behaviour differ according to whether they believe they have eaten more, less or about the same as they normally would. Design: Participants were served a small or large portion of pasta for lunch. Afterwards, they were asked to compare how much they ate in the study to how much...
Article
Food cue exposure has been shown to trigger overeating in restrained eaters. To explore the difficulties experienced by these individuals in regulating their food intake, recent investigations have sought to determine the impact of exposure to a low calorie food cue, but with mixed success. This study tested the possibility that contextual differen...
Article
We conducted a preliminary investigation on the resistance to, and persistence of, social influence regarding the appropriate amount to eat, defined in terms of eating an amount similar to that eaten by a confederate. Participants ate pizza both alone and in the presence of remote confederates presenting either a high or low eating norm. In the por...
Article
Objective: Social factors have a powerful influence on people's food intake but people typically fail to acknowledge the influence of such external cues, instead explaining their food intake in terms of factors such as how hungry they are. We examined whether the tendency to explain one's food intake in terms of internal cues (i.e., hunger) rather...
Article
Norms of appropriateness have been used to account for the influence of a variety of external eating cues (e.g., social factors, portion size) on people's food intake. What is less clear is what, exactly, “appropriate” means. This study explored participants' conceptions of appropriate food intake. Two separate samples were included in this study:...
Article
Pre-exposure to food cues has often been shown to increase food intake, especially in restrained eaters. This study investigated the role of expectations in the effect of such pre-exposure on food intake. A sample of 88 undergraduate women was exposed to visual food cues (photos of grapes and chocolate-chip cookies). In a 2 × 2 × 2 design, particip...
Article
Full-text available
There is evidence that social norm messages can be used to promote the selection of fruit and vegetables in low habitual consumers of these foods but it is unclear whether this effect is sustained over time. It is also unclear whether information about others' liking for a food (liking norm) could have the same effect. Using a 2 × 5 × 2 experimenta...
Article
Large portion sizes are frequently blamed for the obesity epidemic. In this paper, we examine the culpability of large portion sizes. It is true that portion sizes have increased during the obesity epidemic, but there is as yet little evidence that exposure to large portions produces significant weight gain. Furthermore, some evidence argues agains...
Article
Social influences are powerful determinants of food intake. Whereas some people are willing to acknowledge social influences on their food intake, others seem to actively deny being influenced by social cues. Across three samples (total n=835), we examined factors that prior theory and research suggest might predict people's willingness to acknowle...
Article
The portion-size effect (PSE) refers to the fact that people eat more when served larger portions. This effect is neither obvious nor artifactual. We examine the prevailing explanations (or underlying mechanisms) that have been offered for the PSE. The dominant candidate mechanism is "appropriateness"; that is, people accept the portion that they a...
Article
Full-text available
This meta-analysis provides a comprehensive quantitative assessment of research on modeling of food intake. Thirty-eight articles met inclusion criteria. Overall, there was a large modeling effect (r = .39) such that participants ate more when their companion ate more, and ate less when their companion ate less. Furthermore, social models appear to...
Article
The social facilitation of eating (i.e., people eating more in groups than when alone) has been studied for about three decades now. In this paper, we review the empirical research (diary studies, observational studies, and experimental studies) of social facilitation, attending to factors that increase or decrease socially facilitated eating. We a...
Article
Objective: The "unit bias" has been proposed as an explanation for the portion-size effect; people consider a single unit to be an appropriate amount to eat and thus eat more when served a larger unit than when served a smaller unit. We suggest that the unit bias might be better characterized as a "segmentation effect," such that people eat less w...
Article
Wansink and Chandon have examined the "mindlessness" that is often evident in everyday food intake. In this commentary, we focus on four issues raised by Wansink and Chandon's paper: (1) the distinction between food choice and food intake; (2) their model of food intake (and how it compares and contrasts with our own model of food intake); (3) the...
Article
Mate selection seems to be based to some extent on appearance and physique. Assortative mating suggests that romantic partners select each other based on their similarity in important characteristics. Two studies examined the similarity in physiques of members of romantic couples. Study 1 found that the physical measurements of brides-to-be were po...
Article
To determine in a representative Dutch sample the association of dietary restraint, Concern for Dieting, and Weight Fluctuation with subsequent change in body mass index (BMI; in kg/m(2)) in addition to possible moderator effects of sex, level of education, age category, ethnicity, overweight level and physical activity. In a longitudinal study in...
Article
Objective: Two studies examined whether people are aware of social influences on food intake, and whether recognition of those influences is driven by the observation of mimicked eating and/or matching the amount of food eaten. Method: In Study 1, participants watched a video of 1 person eating alone, or a video of 2 people eating together that...
Article
Full-text available
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...
Article
We examined whether a brief education and a brief mindfulness exercise would reduce the effect of portion size on food intake. Participants were randomly assigned to one of the three information conditions (education, mindfulness, or control) and then received a small or large portion of pasta for lunch. Neither education nor mindfulness was effect...
Article
Nutritionists are well aware that people tend to underreport their weights, but psychologists still often rely on weight self-reports. The present paper reviews research on weight underreporting and attempts to identify its underlying motivations. Restrained eaters (and overweight individuals) are especially likely to underreport their weight. We e...
Article
Because emotional and neutral stimuli typically differ on non-emotional dimensions, it has been difficult to determine conclusively which factors underlie the ability of emotional stimuli to enhance immediate long-term memory. Here we induced arousal by varying participants' goals, a method that removes many potential confounds between emotional an...
Article
Full-text available
Numerous studies have shown that people adjust their intake directly to that of their eating companions. A potential explanation for this modelling effect is that the eating behaviour of others operates as an external eating cue that stimulates food intake. The present study explored whether this cue-reactive mechanism can account for modelling eff...
Article
To challenge the conclusion by Jansen et al., Int J Eat Disord 2011; 44:164-168, that the widely used Dutch Eating Behavior Questionnaire (DEBQ) External Eating subscale (DEBQ-EX) lacks validity for external eating, because of limitations of that study. In a seminaturalistic setting we measured participants' intake of crisps and M&Ms while they wat...
Article
Earlier studies assessing the possible moderator effect of self-reported emotional eating on the relation between stress and actual food intake have obtained mixed results. The null findings in some of these studies might be attributed to misclassification of participants due to the use of the median splits and/or insufficient participants with ext...
Article
Full-text available
Numerous studies have shown that people adjust their intake directly to that of their eating companions; they eat more when others eat more, and less when others inhibit intake. A potential explanation for this modeling effect is that both eating companions' food intake becomes synchronized through processes of behavioral mimicry. No study, however...
Article
The obesity epidemic has provoked considerable concern along with suggestions and demands for corrective measures. After surveying the basic features of the epidemic, we turn our attention to self-regulation, which is at the heart of most of the proposed solutions to the epidemic. Information, incentives, and most other tactics to get people to eat...
Article
Objectives: To examine the effects of calorie labeling on food selection and intake in dieters and non-dieters, and to explore whether expectations about food healthfulness moderate these effects. Methods: Participants were presented with a menu containing two items, a salad and a pasta dish. The menu had (a) no calorie information, (b) informat...
Article
Full-text available
Portion size and the intake of others have been found to influence people's food intake. No study, however, has tested the potential influences of both types of situational norms on intake during the same eating occasion. We experimentally tested the effects of manipulating portion size and the intake of others on young women's meal intake during a...
Chapter
This chapter discusses the ubiquity of food cues in our environment and reviews the literature on people's responses to them. Such cues make it particularly difficult for humans to reduce, let alone control, their food intake and, particularly, to restrict their intake to the levels required for life-extension. This chapter also discusses the diffe...
Article
Manipulated perceptions of the portion size of food influence subsequent eating by restrained and unrestrained eaters. In the present study, all participants were served a same-sized slice of pizza. For one-third of participants, their slice appeared larger than the slice being served to another ostensible participant, another third perceived their...
Chapter
In this chapter, we review the research literature on sex and gender differences in hunger and eating behavior. If you ask people about these types of differences in hunger and eating, they will readily identify some: women exhibit certain distinctive cravings during pregnancy and certain phases of the menstrual cycle; men eat more than women do; m...
Article
Full-text available
Numerous studies have shown that the presence of others influences young women's food intake. They eat more when the other eats more, and eat less when the other eats less. However, most of these studies have focused on snack situations. The present study assesses the degree to which young women model the breakfast intake of a same-sex peer in a se...
Article
This study examined whether young men adjusted their snack-food intake to that of a same-sex eating companion. Additionally, hunger was assessed as a possible moderating variable. A total of 59 young men (M age=21.73) participated. An interaction between participants' hunger and confederate's intake on the total amount of snack food (in grams) cons...
Article
Research suggests that caloric restriction (CR) is beneficial; however, the effects of CR in the context of food cues are unclear. A 2 (food cue vs. no cue)x2 (CR vs. ad lib) between-subjects design was employed to test these effects in 40 rats. It was predicted that cue exposure and CR would induce stress, and that these factors might interact syn...
Article
This study investigates the effects of the quality of social interaction on modeling of food intake among young women. A two (confederate's food intake: high versus low) by two (confederate's sociability: sociable versus unsociable) between-participant factorial design was employed. A total of 100 young women (18-27 years) participated. Findings in...
Article
The "false-hope syndrome" suggests that unrealistic expectations are responsible for the cycle of repeated failure and renewed efforts at self-change characterizing many self-changers. Our hypotheses were that: (1) committing to a particular self-change task would inflate initial expectations, (2) participants would be unsuccessful relative to thei...
Article
We examined whether a same-sex peer's vegetable consumption would predict the number of vegetable pieces eaten by the participant. A total of 116 Dutch women (M age = 20.28; M BMI = 21.68) participated. Their nutrient-dense food intake was measured during a 15-min break between two tasks, consisting of rating television advertisements. Participants...
Article
The main aim of this study was to investigate the effects of food-related beliefs about the healthiness of foods, restrained eating, and weight salience on actual food intake during an ad libitum snack. In a 2 (healthy vs. unhealthy) by 2 (restrained vs. unrestrained eaters) by 2 (weight salient vs. not salient) factorial design, 99 female undergra...
Article
Full-text available
We assume that people, to convey positive impressions of themselves, use the amounts eaten by others as limits beyond which their eating may be deemed excessive. One should, therefore, prefer eating partners who eat a lot because others' large intake renders one's own eating nonexcessive. Two studies were conducted to test this hypothesis. As predi...
Article
Few factors have been identified that bolster self-control processes and prevent overeating in restrained eaters; however, research on counteractive-control theory suggests that exposure to food cues may represent such a protective factor. To further investigate the effects of food-cue exposure, restrained and unrestrained eaters were randomly assi...