Received 10 May 2016
Accepted 9 August 2016
Obesity and metabolic syndromes are major threats to health in both developed and developing coun- tries. This opinion article is a holistic attempt to understand the obesity epidemic, by connecting it to the widespread narcissism in society. The narcissism epidemic refers to an increased prevalence of status-striving individualism and a decreased sense of community, observed in Westerns populations and spreading worldwide. Based on social personality and evolutionary psychology approaches, I specu- late that this rise of narcissism underlies a steep social hierarchy resulting in increase of social stress. This social stress markedly affects individuals who are sensitive to social hierarchy dominance due to their personality, yet are relegated at a lower social position. I speculate that over-eating is one major mech- anism for coping with this stress, and discuss the possibility that visceral fat may constitute an adaptive behaviour to the lower social hierarchy position, which is perceived as unjust. Connecting the prevalence of obesity to the narcissism epidemic allows for a more thorough examination of factors, which con- tribute to obesity, which includes early difficult childhood experience, lower rank, and the overall com- petitive framework of the society.
The increased prevalence of obesity is one of the most striking changes in human health . It impedes many progresses in public health and medicine because obesity is associated with comorbidi- ties such as heart disease, type II diabetes, hypertension, and dys- lipidemia . The increase in obesity affects individuals, ethnic groups and countries in an unequal pattern. A number of hypothe- ses have been provided to explain this rise of obesity, such as the recent change toward a sugar and processed-foods enriched diet, a sedentary life style with reduced physical activity. Nevertheless, there is a general consensus among experts that the obesity prob- lem is not simply a personal issue of doing too little exercise and eating too much, but a mismatch between human basic biology, which is the consequence of millions of years of evolution, and modern society. A classical explanation, referred to as the ‘‘thrifty hypothesis”, is that human history was characterized by frequent food scarcities and colonization of adversary climatic zones, and that natural selection had favored individuals who would effec- tively store calories in time of surplus (reviewed in . Therefore, the decrease of physical activities as a consequence of technology and the concomitant increase in food availability in modern society is the alleged etiology of the obesity epidemic. Nevertheless, this theory fails to explain how lower social status individuals, or minorities, are much more affected by obesity, a phenomenon discussed below. Several other evolutionary hypotheses for the meta- bolic syndrome have been proposed, but none of them reach a consensus possibly due to fact that the causes are multifactorial (see [3,4] for extensive reviews).
The purpose of this article is to discuss a hypothesis that views the rising prevalence of obesity as a secondary consequence of the narcissism epidemic and rooting both of them in social dominance interactions. While obesity is often associated to social stress and lower-rank position , hardly any studies have attempted to con- nect the rise of narcissism to the obesity epidemic. I speculate that obesity, and possibly many other diseases that have increased over the last three decades, are a secondary consequence of a society perceived as too competitive and stressful. This would particularly affect individuals who are sensitized by their personality to social dominance hierarchy. It is important to note that this essay does not oppose the classical obesity narrative, which involves the lack of physical exercise concomitant with the availability of processed and sugar-rich food in the modern diet. Rather our proposition is complementary, with an attempt to address why certain individu- als, certain minority groups, and certain societies, as a function of their personalities, are more prone to obesity than others.
The main principles of this article are:
- Human ethnic groups and individuals within a population slightly differ in their predisposition to narcissism. Narcissism could be conceptualized as a higher reactivity to social dominance hierarchy.
- Societal changes have led to a rise of narcissism, notably in the US, leading to a society perceived as more unequal, materialistic, hedonistic and competitive. This rise in narcissism underlies a steep social dominance hierarchy, and is associated with an increased social stress.
- Individuals, whose personalities predispose them to the social dominance hierarchy, but who are relegated to a lower position, are at higher risk for obesity because overeating is a way to cope with social stress.
In this article, I will discuss whether over-eating and increased body weight is just a collateral consequence of the stress, or whether it could have a regulatory function, allowing individuals to re-adjust in the social hierarchy. While obesity researchers tend to examine the problem in terms of metabolism and nutrition, our essay attempts to take a broader perspective on the problem, inte- grating both the psychological and biological dimensions to under- stand obesity.
A social personality view of narcissism
Two forms of narcissism, grandiose and vulnerable
Personality traits are enduring personal characteristics that are revealed in a particular pattern of behaviour. Narcissism is a rela- tively stable individual feature encompassing grandiosity, self- love, a sense of specialness and inflated self-views [6,7]. Two pri- mary forms of narcissism have been defined: grandiose and vul- nerable narcissisms. The grandiose narcissist has been the focus of most studies and corresponds to the classical figure of the nar- cissist in the eyes of the general public. Grandiose narcissists are over-confident, extraverted, high in self-esteem, dominant, atten- tion seeking, interpersonally skilled and charming. However, they are also aggressive, unwilling to take criticism, high in psycholog- ical entitlement and interpersonally exploitative . In other words, narcissists place more value on getting ahead than getting along socially. They tend to score high on traits associated with agency such as extraversion, action, competence and power, but low on traits associated with ‘communion’ such as agreeableness, warmth, kindness, and affection. Narcissists strive for high status as well as leadership position, and they view their close relation- ships as self-enhancement mechanisms rather than partnerships. Grandiose narcissists are attracted by success and fame, and are less sensitive than others to negative social implications such as the costs for the community. Instead, they feel that they are special and entitled to certain privileges. The ‘inflated self’ underlines the trend of narcissistic individuals to over-value their own achieve- ments, while subtly depreciating the contribution of others. Social personality studies have also shown that narcissism has a link with short-term seduction. Narcissists are perceived as more attractive in first acquaintance, but this positive view tends to decrease over time when the others discover that their own interests are not taken in consideration by the narcissist. According to the Big Five classification of personality, grandiose narcissism is characterized by high extroversion and low agreeableness . The term ‘low agreeableness’ could seem surprising, as narcissists often appear charming, but this charm tends to vanish in the long term when they reveal their self-centeredness.
Like the grandiose narcissists, vulnerable narcissists are filled with grandiose dreams, specialness and entitlement, but at the same time, they feel intense shame regarding their needs and ambitions . Thus, the dominant emotion is shame rather than aggressiveness. Because of this antagonistic interaction between high expectation in life and shame, vulnerable narcissists have dif- ficult interpersonal relationships. They are very sensitive to the opinion of others, being easily hurt or embarrassed, and can be paranoid, thinking the world is unfairly stacked against them. Using the dimensional approach, vulnerable narcissism is charac- terized by low agreeableness and high neuroticism. People with pronounced neuroticism are characterized by impulsivity, greater anxiety, depression, vulnerability and hostility. They are much more sensitive to social stress than other individuals.
While grandiose and vulnerable narcissism are associated with an inflated self, both forms are accompanied by a higher depen- dence on the regard of the others for admiration (grandiose) or acceptance (vulnerable). As described later, this higher dependence on the regard of others fits very well the notion that narcissism is intricately linked with social dominance hierarchy. Narcissism is a complex personality taxon, and those commonly called narcissists score high on several dimensions associated with narcissism. It is extremely important to note that the social-personality literature conceptualizes narcissism as a trait that is normally distributed in the population and for which there is no clear cut-off for ele- vated narcissism. Thus, there is no dichotomy between narcissists and non-narcissists, but individuals that differ in an indefinite vari- ety along this trait. The psychiatric literature conceptualizes severe form of narcissism as the Narcissistic Personality Disorder. The descriptions of strong forms of narcissism have been given above to illustrate this personality, but this essay will focus on the mild, non-pathological form of narcissism, and notably on vulnerable narcissists.
Narcissism and parenting
Psychological studies have shown that narcissism is strongly influenced by the mode of parenting . One theory links narcis- sism to excessive parental admiration and overindulgence, which leads children to believe that they are the center of the world. Nar- cissism associated with the child-king cult and self-focused upbringing would explain in part the recent rise of narcissism in Western societies, notably in the US . Another theory views narcissism as the result of a parenting mode that is excessively guided by parental self-focus. Child narcissism develops as an adaptive response to a parenting style that uses the child as a means to satisfy the emotional needs of the parents (e.g., their ambitions). A third theory suggests that parental neglect or rejec- tion might also lead to narcissism by creating a sense of emotional deprivation. In fact, the most severe forms of narcissism are linked to under-parenting, such as the absence of one parent, the neglect or abandonment of the child, the perception of favouritism toward another sibling. In this case, the inflated self could be seen as a des- perate mechanism to attract attention from the entourage that the individual had been lacking during childhood.
It is interesting to note that narcissism is a trait that tends to show an apparent inheritance through upbringing: narcissistic par- ents tend to nurture narcissistic kids. For instance, adults who became narcissistic due to parental over-evaluation and indiscrim- inate praise will tend to inflate achievement of their own children. Similarly, adults who had a difficult childhood because their par- ents neglected them, will have more difficulty to establish endur- ing marital relationships, and might eventually abandon their own children. While social personality psychology makes a strong emphasis on parenting, the origin of different forms of narcissism might be better explained in the general evolutionary framework of parent-offspring with an important role of pre-natal and post- natal stress as mediators of these conflicts .
An evolutionary biology perspective on narcissism
Evolutionary psychology is an emerging research field, which hypothesizes that many human psychology traits and behaviours have a genetic basis, and that the underlying alleles have been selected for during evolution. We will now analyse theories, which have linked the grandiose form of narcissism to short-term mating strategies and social dominance.
Narcissism and short-term mating
The immature human baby requires optimal parenting, which involves substantial efforts by both the mother and the father. This implies that human ancestry probably underwent positive natural selection for pair-bonding, at a time when the benefits of parental investment in long-term relationships probably began to outweigh the benefits of promiscuous strategies. Holtzman and Strube sug- gest that this new set of selection pressure may have created vari- ation in human personality traits that alters mating behaviour . Despite this inclination toward long-term mating strategies favouring bi-parental childcare, residual short-term mating strate- gies are still maintained in the human species. The authors suppose that short-term mating strategies are at the core of narcissism, and that other traits associated with this personality derive from these strategies. Their key point is to see narcissism as a strategy of short-term seduction with high attractiveness, exhibitionist charm and interpersonal skills. Since narcissism trait levels vary continu- ously in the human population, it might be more appropriate to see the level of narcissism as the degree of proclivity to pursue short- term mating and adopting a mode of interaction based on seduc- tion rather than empathy . This hypothesis has the value to explain the link between narcissism and seduction that has been the focus of much social personality research.
Narcissism and dominance
Another complementary view of narcissism is centred on social dominance [15–17]. There is strong evidence that psychological mechanisms similar to the underlying dominance hierarchy in pri- mates are also present in humans and influence human social hier- archy . The social attention holding potential (SAHP) theory suggests that differences in social rank do not stem from threats or coercion in our species, but rather from differences in the amount of attention conferred by others [19,20]. According to the SAHP theory, humans compete with each other to be noticed and valued in a group; when a group member bestows a lot of high quality attention on an individual, that individual rises in status. In contrast, ignored individuals are banished to a lower status. Interestingly, the extended sociometer theory revisits the self- esteem concept by proposing that it represents a status-tracking mechanism: an increase in self-esteem could signal an increase in the degree to which one is socially included and accepted by others [21,22]. Since social acceptance is likely to have been critical to survival and breeding success, evolution would have favored a mechanism that enables an individual to track his or her degree of acceptance by others. This mechanism could provide a feedback of one’s place in the social hierarchy and help to take decisions about challenging or submitting to others.
Consistent with the hypothesis associating narcissism to dominance, grandiose narcissists are striving for position of power and are actually often found in the head of institutions, firms, hospitals and politics, positions. Many personality traits associated with dominance are also similar to narcissism, including physical attrac- tiveness and charm, deep understanding of social relationships (‘‘mind-reading” ability), strong investment in forming powerful alliances (networking abilities), and presence at the center of attention. Grandiose narcissism is characterized by high selfesteem, which according to the sociometer theory signals a high position in the hierarchy.
Both, the social personality approach that focuses on personality traits and attitudes and the evolutionary psychology approach that attempts to decipher their biological origin, complement each other very well. Entitlement, desire to get ahead rather than along, aggression towards challenging of status, selective socialization with the most influential individuals, are all traits associated with dominance. The capacity to seduce, inflated self, perpetual dissat- isfaction (impulsivity) and the lack of empathy are traits that iden- tify more with short-term mating. For Holtzman and Donnellan, short-term mating strategies and dominance are the underlying factors resulting in narcissistic traits  and their co-variation explains the complexities of the narcissism personality. In this model, inputs from the environment determine which program is activated at a given time.
Finally, consistent with the evolutionary psychology hypothesis associating narcissism to short term mating strategies, narcissism peaks at adolescence and in young adults and decreases with age . Adolescents and young adults are characterized by higher short-term mating activity, while adolescence refers to the delicate period of life when humans find their position in the social hierar- chy. Use of the narcissistic personality index (NPI) indicates that narcissism is slightly higher in males than in females . This is consistent with observations indicating that men tend to strive more for status and have more to gain from short-term mating strategies compared to women .
Speculations on the vulnerable narcissism form
Vulnerable narcissists are extremely sensitive to other people’s opinion and often ‘personalize’ harmless statements in a discus- sion. They have great expectations of themselves, and search the approval of the other. In the most severe form, these individuals have difficulty to handle any criticism, which could be seen as a strategy to protect the self-esteem (i.e. the status). When someone over-reacts and personalizes seemingly insignificant elements of a discussion, we tend to be very careful with this person to avoid any confrontation. This confers to such individual a special status and suggests that the vulnerable narcissism form could also be linked to social dominance hierarchy. Vulnerable narcissists could be seen as individuals who are susceptible to social dominance hierarchy because of their fragile self-esteem.
Narcissism viewed as an emergent property
The influences of the parenting style and the child temperament on the extent of narcissism have been described. The third ele- ment, which influences narcissistic trait development and expres- sion, is the conceptual framework of the society, and the overall level of inequality in the society. This complex interrelationship between individual difference, parenting/childhood experience, and influence of the framework of the society become obvious when we take in consideration the link between narcissism and social dominance hierarchy. Our position in a social hierarchy is not just an intrinsic property of an individual, but is an emergent property. A narcissist is an individual, who as a consequence of parenting, pre-natal and post-natal experiences and his or her tem- peramental proclivity, is more sensitive to the social dominance hierarchy. At the same time, the steepness of social dominance hierarchy is the result of interaction between all the members of the group. A human society with a low level of inequality, con- straints that frame the human life, and an emphasis on community will tend to reduce the expression of narcissistic traits.
Evidence and consequences of a rise in narcissism
The rise of narcissism underlies a steepest dominance hierarchy
In their book ‘‘The Narcissism Epidemic”, Campbell and Twenge analysed the spread of narcissism and its damaging consequences in the US society . The authors used experimental and histori- cal data to show that the narcissism score of US-Americans has never been so high and that the shift was especially pronounced in women [12,24]. The symptoms deriving from a rise in narcissism are multiple: materialism, vanity, sense of specialness, antisocial behaviour, exaggerated overconfidence, game playing conception of love, crude sexuality and a strong sense of entitlement (see ). Other symptoms are the desire for status–defining objects, as exemplified by the prosperity of the luxury good industry, despite the economic crisis. There is also the recent emphasis on physical appearance as illustrated by an increased time spent on grooming and the rise in aesthetic surgery. This raise of narcissism is also associated with a more pronounced need for individuality and ‘‘being different”, as evidenced by the rise in ‘‘original” first names, tattoos, piercing or special diets . The authors also pro- vide evidences for the spread of these symptoms to many other nations beyond the US. However, the reasons at the root of this rise in narcissism are not clear. Permissive parenting (‘child-cult’) and self-esteem–focused education, family de-structuration, media culture that provides an echo chamber to narcissists, internet and social networking, decline of traditional religions that con- straint social life by rites, lower synchronization as a consequence of increased individualism, ethnic heterogeneity as a consequence of migration, are all possible explanations for this change [12,15]. This rise of narcissism might not be necessarily historically new, but it would be more visible today with the acceleration of time and the progress in psychology.
Taking into consideration the hypothesis from evolutionary psychology that conceptualizes social dominance as part of the evolutionary basis of narcissism, I have speculated that this rise of narcissism is the visible manifestation of a steep social domi- nance hierarchy . This would mean in a society where individ- uals behave more strategically to achieve their goals and to get ahead, they take less care of the consequences of their actions to the community. An increase in narcissism would explain the sharp increase in inequality (‘‘the rich get richer”) despite the strong human interdependence. In addition, a hypothesis from evolution- ary psychology that conceptualizes short-term mating strategies as the other underlying evolutionary basis of narcissism links this rise of narcissism to a weakening of traditional (monogamous) values and the diminished existence of enduring relationships, which are replaced by relationships based on seduction with a constant need for excitation.
A rise of narcissism leads to a decrease in social capital
The main consequence of high narcissism is a deterioration of trust in relationships. Narcissism is linked to short-term seduction and the use of the other for self-enhancement purpose. Those who suffer from a relationship with a narcissist, suffer also because this type of relationship weakens the trust in others . The last 30 years have been characterized by a sharp decrease in trust towards our elite, including bankers, investors and politicians . This decrease of trust is especially prominent in the romantic domain, where short-term seduction and game playing concept of love become more prevalent. By decreasing trust at the work place or in the affiliate domain, high narcissism decreases the social cap- ital, which is defined by a sense of community and trust in others . Social scientists and health experts have noticed for a long
time that in Western societies, economically poor individuals (those at the bottom of the social hierarchy) experience decrease of health and longevity. Accordingly, stepwise descent in socioeco- nomic status (socioeconomic status means income and/or educa- tion level) predicts increased risks of cardiovascular, respiratory, and psychiatric diseases; infant mortality and also obesity, despite good access to modern medicine . Studies have shown that this relation is predominantly a consequence of socioeconomic status on health, rather than the opposite. As stated by Sapolsky, ‘‘poor health is not so much the outcome of being poor, but of feeling poor” . Thus, a decrease of social capital could be a prevalent factor driving obesity and many other diseases. With the obsession of grandiose narcissists for specialness, rank and attention, a rise of narcissism is expected to increase the perception of being poor and disadvantaged for those individuals of a lower social standing.
A reasonable hypothesis is that this rise of narcissism is associ- ated with an increased level of stress, notably ‘‘threat stress”, described as diffuse stress that one does not have the resources to cope well with, such as impossibility of opposition to precise identifiable stressors. Indeed, a large part of the damage of narcis- sism is inflicted at the meta-organizational level, and is invisible to the community. One example is the economic crisis, caused by the self-interests of skilled and charismatic financiers and bankers, individuals whose behaviour has been routinely associated with narcissism . Another type of stress concerns the instability of marital relationships, especially since a divorce is often considered as the second-most stressful life experience, second to the death of a closely related person. In a narcissism-oriented society obsessed by ranking, physical appearances, wealth and status, our own standing and achievements are constantly challenged. This chal- lenge is especially strong because we are constantly exposed to a media culture of glamorous and self-confident celebrities, while being at the same time responsible for our own real or perceived failures. Such conflict can especially affect individuals with a frag- ile self-esteem, which as described earlier, can be seen as a status- tracking mechanism to evaluate our position in social hierarchy [21,22].
In summary, I hypothesize that the rise of narcissism creates a steep social dominance hierarchy, thus resulting in a more stressful society. This would explain the paradox, that despite their compa- rably high level of wealth, health and technology, many westerners perceive their society as more competitive and more stressful. Interestingly, a large amount of data has already associated obesity to stress, providing a link between the rise of narcissism and obesity.
From a rise of narcissism to obesity
While there are still on-going efforts to decipher in non-human primates whether it is the dominant or the subordinate individuals who experience more stress, there is a global agreement that social dominance hierarchy is largely established by psychological stress through coercion and threat [18,20,26]. Extrapolations of these observations from non-human primates suggest that a steep dom- inance hierarchy may lead to social stress in our society. This stress should more strongly affect the individuals high in narcissism as their personalities render them more sensitive to the social domi- nance hierarchy (i.e. higher sensitivity to the regard of others). Although this social stress should also affect grandiose narcissists striving for high status, it should be especially effective on vulner- able narcissists because of their fragile self-esteem but sensitivity to the regard of others. Furthermore, vulnerable narcissism is char- acterized by neuroticism, a personality dimension associated with higher sensitivity to stress .
This led us to the central idea of this essay, whereby increase of social stress resulting from a steep social dominance hierarchy affects predominantly certain lower ranked individuals, whose personality instils a feeling of entitlement. Their over-eating could be one option to cope with this stress.
Chronic stress, notably social stress, promotes obesity
In addition to higher caloric consumption and lesser physical activity, experts in obesity recognize that stress arising from social situations and work interacts to promote the development of obe- sity and related metabolic syndrome . It is important to note that stress is linked to visceral obesity, which is described as an excess of abdominal fat around internal organs such as the liver, pancreas and intestines and stomach. More importantly, studies have shown that visceral fat is a better predicator of obesity- related disease risk than total body fat mass .
Food intake, beginning from the first breast-feeding, is soothing and provides comfort. Thus, over-eating could be viewed as a cop- ing mechanism to deal with excessive stress. The ‘‘stress-eating” or the ‘‘comfort food” hypothesis sees the excessive consumption of food, notably that with high palatability and caloric value, as a means to cope with psychological stressors [30–33]. The increase in food intake is considered a response to an emotional stress, to diminish the distress in the short term.
Supports for this stress hypothesis are numerous and can be found in epidemiological studies demonstrating a correlation between waist to hip circumference ratio, low social economic sta- tus and job stress [34,35]. The stress hypothesis is also reinforced by a number of experimental observations in animals exposed to chronic social stress, where they display abnormal changes in their body fat distribution [33,36,37]. Clinical research have shown that individuals with low socioeconomic status, who were repeatedly subjected to psychological and economical stressors, developed both perturbation in hypothalamic-pituitary adrenal axis, a major pathway involved in the production of glucocorticoid hormone, and increased visceral adiposity [5,38]. The link between elevated levels of the stress hormone cortisol and visceral fat accumulation is also supported by multiple studies [32,39]. For instance, human subjects treated with corticosteroids eat more, which may there- fore promote obesity [40,41]. These findings strongly support the role of glucocorticoids in the development of obesity. Moreover, a number of other metabolic disease models have also established the importance of the hypothalamic-pituitary adrenal axis and chronic stress in weight gain [30,32].
In addition, the stress hormone cortisol has also been linked to social dominance through a complex interaction with testosterone. While the link with aggressive behaviour is still uncertain, there is rather a good correlation between basal level of testosterone and status-striving personality traits in both males and females [42,43]. Together with the stress hormone cortisol, testosterone affects the social behaviour linked to status . A number of stud- ies suggest that testosterone levels are correlated to dominance only in individuals with low cortisol level . It is striking to note that plasma testosterone levels are inversely correlated with adi- pose tissue mass, and that half of obese male individuals display low levels of testosterone [45,46]. If dominance is achieved by a high level of testosterone and low cortisol, obese individuals with a low level of testosterone and a high level of cortisone will be expected to behave as subordinate. Interestingly, injection of testosterone has a positive effect in the management of obesity in obese males with a testosterone deficiency. Long-term testos- terone therapy does not only reduce waist circumference and BMI but also improves motivation, vigour, energy, and reduces fati- gue .
The observations that two hormones, testosterone and cortisol, are associated with social dominance and propensity for obesity, somewhat connects obesity to social dominance hierarchy.
Linking narcissistic traits to over-feeding
I will now enter a more speculative part of this essay to analyse how certain traits associated with narcissism could be connected to over-eating. Social personality studies note that narcissists over- sell their accomplishments, and have higher expectations when compared to non-narcissists. This over-sizing is linked to the con- cept of inflated self at the core of narcissism personality. This over- sizing is non-conscious and could be considered as a cognitive bias that could also affect the feeding behaviour. This could lead to an excessive appetite (‘‘the eyes bigger than the tummy”) or to over-feed the others by dishing out excessively large and calorific food portions. Studies have indeed shown a marked increase in the size of US-American food servings in the last three decades [47,48].
It is interesting to relate other narcissistic traits to the lack of exercise. Narcissists are capable of strong effort when they get public recognition. Successful grandiose narcissists enjoy individu- alistic sportive exploits (alpinism, marathons.. .), which push their limits, in an attempt to prove their agility and competency. Never- theless, when narcissistic individuals do not get any recognition, they do not make any effort and tend to stay self-absorbed. With- out peer recognition, narcissists rather engage in activity that gives them an immediate excitation (internet, TV, video games). These individuals are also less able to endure demanding activities, and may rather stay hidden at home than exposed to the regard of others, due to their high susceptibility to ego threat. The observa- tion that injection of testosterone in testosterone-deficient obese male individuals not only reduces body fat but also increases moti- vation and activity, suggests that the lack of physical exercise asso- ciated with obesity is rather a consequence of a subordinate position than of fat excess per se. There is also evidence from other mammals supporting a link between subordination and low activ- ity [37,49]. This lack of exercise could be related to a state of depression (see below) that often accompanies obesity .
Although this remains speculative, the stronger dependence of narcissists on the regard of others could make them more vulner- able to the general reduction in social interaction and de- structuration of the social environment in the last three decades. Since social attention (being the center of attention of the other) is an indication of status, it is likely that the recent increase in time spent on screen (e.g., computer and television) in our society, may contribute to obesity, beyond mere inactivity because it sequesters our regard towards the others and thereby depreciate our close rel- atives and friends.
Correlations between the narcissism and the obesity epidemics
I will now discuss a number of correlations consistent with the notion that the obesity epidemic could be a secondary conse- quence of the narcissism epidemic.
A concomitant increase in obesity and narcissism
The first notion relates to the rise in obesity and narcissism. The last three decades have been characterized by an increase in opportunism in love, crude sexuality, celebrity cult, wealth inequality, individualism, and a parallel rise in obesity .
Secondly, the worldwide increase of obesity seems to follow the increase of individualism, rise of aesthetic surgery, decrease of family and traditional values. Obesity is rather prevalent in the USA, which ranks among the most narcissistic nations in the world . USA is also one of most unequal countries, which is worsened by constant exposure of poor individuals to ultra-rich and extrav- agant lifestyles, as well as by celebrity cult through media expo- sure. In contrast, European countries such as Denmark, Sweden or France, which invested significant efforts to combat inequality and have a stronger communal spirit, show significantly less wide- spread obesity. Social norms or a pro-social religious framework, which reduce inequality and short-term mating strategies, are expected to reduce the expression of narcissistic traits. Yet, as Twenge and Campbell suggest, the narcissism epidemic is spread- ing worldwide, as seen from indicators such as the increase in aes- thetic surgery in Latin America .
Increased prevalence of obesity in certain minorities
The status of being a minority should increase the feeling of specialness and is often associated with negative life experiences (e.g., difficult childhood, humiliation, discrimination, decreased socialization), both of which affect the level of narcissism. In par- ticular, there is a good correlation between obesity rates and nar- cissism levels in US ethnic groups. Obesity is more prevalent in African-American and Hispanic populations than in European Americans, and European Americans are in general more obese than those with an East-Asian origin. Although these numbers should be taken with a grain of salt, the use of the Narcissistic Per- sonality Index (NPI) suggests that black Americans score higher on the narcissism scale than Europeans Americans, and as expected, East-Asians have the lowest score . Although surprising when considering their disadvantageous position, it is well known to psychologists that Black Americans have higher self-esteem than the overall US population [51–53]. The degree of narcissism in this US ethnic group also correlates with the percentage of single- parent families. As poor parenting leads to increased narcissism in the progeny, both factors, father-absence and narcissism, should reinforce each other in a vicious circle. Importantly, this NPI mea- surement of narcissism in ethnic populations does not mean that differences in the level of narcissism are fixed genetically. Mea- surements of narcissism levels in Hispanic community using NPI lead to contradictory results. Hispanics NPI scores fall either between black and white or between white and East Asian US- Americans . Given that Hispanics are recent immigrants, it is likely that they are initially protected by their Latino-American tra- ditions, which provide a pro-social and pro-family framework. However, those who are immersed in the individualistic and protestant-based social framework of the US, soon become less protected against the ambient culture, and become more narcissis- tic. Furthermore, the low prevalence of obesity in the East Asian minorities also correlates well with their lower NPI score. Collec- tively, these observations suggest that not all human groups gain weight in response to social stress, and could suggest differences in temperamental proclivity in certain ethnic groups.
A positive correlation between obesity and neuroticism
A number of studies have compared the personalities of obese and non-obese populations (reviewed in ). Although complex to interpret, the majority of these population-based studies indi- cate a positive association of neuroticism with overweight/obesity. One facet of neuroticism that has been associated with obesity is impulsivity. Impulsivity could lead to obesogenic behaviours, such
as difficulty to restrain eating in stress condition or giving into non-social activities with short-term pleasure (TV or video game) over physically-demanding ones. Finally, personality studies have demonstrated that conscientiousness, a trait negatively correlated with narcissism, is protective against overweight .
Vulnerable narcissism is associated with neuroticism and low level of conscientiousness. The association between obesity and these personality traits raises the question whether the latter are a consequence of obesity, or rather factors contributing to obeso- genic behaviours. In the first case, these traits would be a sec-
ondary consequence of the social prejudice associated with obesity. Obese children are often being stereotyped as unhealthy, socially inept, academically unsuccessful, unhygienic and lethargic [55,56]. Instead, I suggest that the personality traits (and their underlying biological origin associated with dominance) may either promote or have a bi-directional interaction with obesity, which may be considered as a stress coping mechanism (see below for further discussion).
Difficult childhood is a risk factor for both vulnerable narcissism and obesity
While the direction of causality between personality traits and obesity is difficult to disentangle, both obesity and vulnerable forms of narcissism are influenced by parenting. Deprivation in childhood and parental neglect increases the risk of obesity by 7–10 times [57,58]. For instance, obesity is common in adults who have been abused or abandoned in their childhood. That the same developmental factors, difficult childhood and poor parental care, are also conducive to both the vulnerable form of narcissism and obesity is consistent with a model rooting both processes in social dominance hierarchy.
Transmission of narcissism and obesity
A striking feature of the obesity epidemic is the increase in childhood obesity. Obese couples tend to give rise to obese chil- dren, and four out of five obese children will remain obese in adult- hood [59,60]. This is comprehensible with our model that links obesity to narcissism, whose underlying biological roots are in the social dominance hierarchy. Indeed, as mentioned above, nar- cissism as a personality seems to be ‘‘transmitted” because narcis- sistic parents tend to raise narcissistic children. Of note, studies show that dominance can already be observed in two-year old chil- dren, supporting the idea that this trait is developed very early in childhood . In this line, it worth mentioning that both over and under-nutrition are risk factors for obesity [61,62]. This appar- ent conundrum can be resolved when considering the link between narcissism and obesity, because narcissism can arise from both child over-evaluation and under-parenting.
All the correlations discussed above do not clarify the direction of causality or the presence of other major factors. Instead, they only provide elements supportive of our hypothesis. Viewing the narcissism epidemic as the underlying cause of obesity epidemic is appealing because it would explain why certain countries are more affected than others, and why within these countries, certain ethnic minorities and individuals are more affected than others.
Is visceral fat gain a regulatory mechanism in the establishment of social hierarchy?
The main hypothesis of this article is that over-eating and the resulting weight gain constitute a coping mechanism to individuals whose personality instils both a feeling of entitlement and a vul- nerability to social-stress. This coping mechanism would be more prevalent when these individuals find themselves in a lower rank position. It is their actual stress over their perceived (and not the actual) status, that should be taken in consideration because these individuals perceive stress to be higher than it really is, due to their personality. Thus, over-eating could be viewed simply as a mecha- nism to distract these individuals from their negative and stressful experiences, consistent with the notion of ‘comfort food’. An alter- native view is that visceral fat in obese individuals also serves a regulatory function, allowing the readjustment of the overweight individuals in the social dominance hierarchy. The idea would be that visceral fat somewhat re-adjusts the personality towards being less aggressive, less ambitious, and possibly more sub- servient, with a higher fascination for the dominant individuals. This would promote integration in the community, and encourage acceptance of the lower position. As an underlying mechanism, vis- ceral fat might affect hormonal levels associated with social dom- inance, for instance by lowering the plasma levels of critical hormones such as testosterone and cortisol. This would make the obese individual less dominant and less sensitive to the ambient social stress. A regulatory role of visceral fat could be the legacy of an ancient evolutionary mechanism involved in social domi- nance. Incidentally, the accumulation of visceral fat may have been greatly exacerbated by the availability of sugar-enriched and pro- cessed food in the modern diet. Alternatively, it could be an evolu- tionary new regulatory mechanism of stress coping, possible today due to the excessive availability of energy-rich food.
There are a number of observations supporting a stress-coping role for visceral fat. For instance, a study in macaques has shown that abdominal obesity is associated with low social status . It is also striking that anorexic women, devoid of any adiposity, are usually viewed as more competitive and engaging in recognition-demanding activities, such as ballet dancing or exces- sive physical exercise. Anorexia has also been associated with the narcissistic personality . Anorexia and obesity could represent two opposite responses to social dominance hierarchy, with the former being about maintaining a dominant style through higher activity and higher sensitivity to stress. The latter is about accept- ing a subordinate style, with lower activity and less sensitivity to stress. Similarly, intense body building activity and obesity could represent opposite responses in men, leading either to mesomorph shape in status-striving individuals and more adiposity in less competitive individuals. In this regard, the human body shape could provide insights into our personality. Consistent with this, humans tend to associate certain personality traits to body shape, which can function as a social signal .
The point is that an increase in social dominance hierarchy (i.e. the rise of narcissism) should act as a differentiating factor that broadens a trend towards extreme shapes: thinner (female) or mesomorph (male) versus overweight. It is interesting to note that many teenagers and young adults, especially females, exhibit peri- ods of alternative weight loss and gain following successful diet and relapse times. Adolescence and young adulthood correspond to psychologically difficult times, where individuals find their posi- tion in the social hierarchy. Studies have shown that individuals with concern about their weight (i.e. restraint dieters) are at risk of weight gain upon stress. This concern with one’s own weight could reflect a higher sensitivity to social dominance hierarchy.
It is well established that obese individuals, especially obese females, have a lower self-esteem. The classical vision views the low self-esteem of obese individuals as the interiorization of the negative regards from the entourage [55,56]. The notion that vis- ceral fat could have a regulatory function suggests an alternative interpretation, in which the decrease of self-esteem reflects a decrease of status. This is consistent with the sociometer theory that views self-esteem as a status striving device.
In conclusion, accumulation of visceral fat could be a coping mechanism for individuals subjected to dominance, allowing them to re-adjust in the social hierarchy by modulating their hormonal level. This would promote the acceptance of a lower status to avoid confrontations and possible violent altercations. An interesting prediction deriving from this hypothesis would be that with equiv- alent socioeconomic level, ethnical background, and childhood conditions, obese individuals should be less violent than athletic individuals.
In primates, social dominance hierarchy often results in the control of reproduction by the most dominant members of the group. It should be noted that overweight humans have reduced fertility abilities [66,67] and that obesity impedes a normal sexual life, as obese individuals are deemed less attractive . Thus, it cannot be excluded that such anti-reproductive outcomes resulting from stress-induced weight gain in others may be a mechanism for dominant individuals in our society to monopolize the mating pool. Evolutionary psychologists consider that humans use thin- ness as a criterion of fertility in female, but it cannot be excluded that it also signals high status. This would explain our unconscious negative feelings towards obese individuals.
Obesity among other submissive strategies
It is often stated that obesity is a ‘mask for depression’, or that there is an ‘‘underlying depression” defended against by the obe- sity. The risk factors to develop obesity and depression are similar: both have been linked to stress and neuroendocrine dysfunction as well as autonomic abnormalities. In addition, obesity tends to increase the risk of depression . The psychologist Paul Gilbert already proposed that social anxiety and depression relate to defensive submissive strategies when individuals find themselves placed in lower status . Depressed individuals enter into a phase of latency, removing themselves from confrontation in social life, while waiting for a better situation. Depression and obesity could be viewed as two related coping responses to social stress. Other responses involve the use of violence (contesting the social hierarchy) or substance abuse (drugs, alcohol, tobacco). The obser- vation that cessation of smoking often leads to weight gain due to overeating is indicative that both mechanisms play a similar role for coping with social stress. It is likely that inputs from the envi- ronment (childhood experience, socioeconomic parameters, minority status, constraints of the society) and biological parame- ters (temperamental proclivity, ethnicity, gender) determine which adaptive program is utilized in an individual at a given time. Depression would be more adapted to a transient loss of status while obesity could be more adapted to a permanent state of low status.
The rise of narcissism and its impact on other diseases
Obesity might not be the only disease affected by the narcissism epidemic. The last decades have been characterized by the sharp increase in the frequency of many diseases in Western societies such as allergies, autoimmune diseases, food intolerance, back pain and eating disorders, in addition to psychological ones. Changes in our alimentation habits, modifications of the intestinal microbiota, excessive use of antibiotics, influences of pesticides and pollution are among the alleged reasons underlying the recent increase of these diseases. However, much less discussion is made about the psychosomatic nature of diseases as a secondary consequence of the rise in narcissism. A vast body of research has causatively asso- ciated psychological stress with a variety of concrete physiological disorders, affecting immune system, digestion, sexuality and brain functions .
Anorexia usually affects young women who are perfectionists and competitive (e.g., classical ballet dancers, models), while thin- ness is associated with self-control. It is suggested that this type of eating disorder is exacerbated in Western countries, which pro- mote slimness as attractive, leading to the depreciation of ‘‘nor- mal” women . While many seemingly independent disorders such as food intolerance, eczemas and allergies could be due to environmental changes, a portion of them could have psychoso- matic origins, and the raise of narcissism might partially explain their increase in modern society. These diseases increase the feel- ing of specialness and put individuals apart from the group. For instance, requirement for a special diet unconsciously marks a spe- cial status. This tells the child that he is different from the others, encouraging individual differentiation. Some of the diseases are also a way to get attention from the family and peers, and to pro- tect ones’ self-esteem by externalizing difficulties. It is worth underlining in this context that the gut is an extremely well inner- vated organ, often called the second brain. The human gut (and likely its microbiota) is extremely sensitive to stress, and it would not be surprising that the gut and its associated nervous system contribute to the establishment of social hierarchy by regulating stress-mediated interaction between humans. Consistent with this view, experts have reported a higher incidence of eating disorders and food intolerance in vulnerable narcissists, which suggests that their intestines could be more sensitive to stress than others . In a narcissism-oriented society, dominated by freedom and indi- vidualism, failures are much more difficult to accept because they directly challenge individual qualities and values. This would explain the prevalence of psychological disorders (e.g., anxiety and depression) associated with fragile self-esteem notably in teenagers. Hence, diffuse stress linked to a steep social dominance hierarchy is likely to result in many more health issues than obesity.
Using new concepts of narcissism from social-personality research and evolutionary biology, I speculated that a significant part of the obesity problem derives from the recent rise of narcis- sism, reflecting a steep social dominance hierarchy. This increase of narcissism would be a source of a diffuse stress, which affects indi- viduals sensitized by their personality to social dominance hierar- chy. It is no surprise that this competitive framework is expected to affect certain vulnerable individuals, who are relegated to lower socioeconomic position and whose personality instils a sensitivity to the regard of others. The point is that our personalities are framed by our biology and not just a habit that can be easily discarded. Here again, it is worth to repeat again that it is the ‘per- ceived’ stress and rank that matters since it is our personalities and their underlying biology, which prime the differently sensitive individuals to the same stimulus.
Our theory is in line with obesity experts, who have stated that one of the main issues in our society today is that it is perceived as too competitive with undue emphasis on physical appearance. This essay is by essence reductionist, and does not attempt to assess all forms of obesity, some of which are likely to have other origins. Nevertheless, it offers evidence to the notion that chronic stress is a causative factor of obesogenic behaviours. It also roots the well-known correlation between low socioeconomic status and bad health in social dominance hierarchy interaction. By linking obesity to social dominance hierarchy, we can expect differences in likelihood for obesity according to gender and possibly ethnical backgrounds, since human populations might slightly differ in their temperamental proclivities to narcissism. Finally, our essay views obesity as a response, among others such as violence, depression, and substance abuse, as a coping mechanism against the reluctance of certain individuals to become subordinate. The amplitude of obesity is also likely to be amplified as food availabil- ity is no longer limited and physical efforts have become optional.
One interest of the model is to link early childhood experience to obesogenic behaviours and to make obesity conditional to cer- tain environments beyond food availability. By connecting the nar- cissism epidemic (a social-personality view) to a steep social dominance hierarchy scale (an anthropological view), I associate the current rise of individuality, the wealth and sexuality inequal- ity, the difficulty to establish enduring relationships and the con- comitant decrease in social capital, to changes in biological parameters that affect human behaviours. It will be of interest to observe in the future if the current increase of narcissism is just transient, which could prefigure a positive societal change, or if it will further extend with possible deleterious consequences.
Current efforts to manage the obesity pandemic are centred on reducing sugar-enriched diet and processed food as well as pro- moting exercise. Experts recognize that these approaches are diffi- cult to implement and generally fail to stem the rise in obesity in the long term. To date, family lifestyle interventions through beha- vioural therapy are measures that do provide a certain long-term benefit. Changing the personality of an individual remains a chal- lenge. This difficulty is especially true for narcissists, both vulner- able and grandiose, because they are extremely attached to a positive view of themselves and have difficulty to handle critics. Our essay raises the notion that an optimal intervention against obesity should include measures to combat the narcissism epi- demic, such as those that instil community spirit, with a better equilibrium between personal achievements and collective benefit. The fight against narcissism is not an easy task because its ascend is societal and complex. Table 1 lists a number of recommenda- tions both at the parenting and societal levels that could dampen down the narcissism epidemic.
I thank Nathalie Vionnet, Carmen Sandi, Leonid Schneider, Marie Meister and Alfred Chng for comments on the manuscript.
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