Eating disorders and intrasexual competition: testing an evolutionary hypothesis among young women

A Slim Majority: The Influence of Sex Ratio on Women's Body Dissatisfaction and Weight Loss Motivations

The current investigation examined whether women's perceptions of the sex ratio (ratio of women to men) in the local population influence their body dissatisfaction and weight loss motivations. A higher ratio of women to men in a given population signifies a relative abundance of same-sex mating competitors, intensifying female intrasexual competition. Five studies (N = 1,776) tested the hypotheses that women's perceptions of a female-skewed sex ratio would correspond to increased feelings of intrasexual competitiveness and perceptions of unfavorable mating prospects, which would, in turn, be associated with heightened body dissatisfaction and weight loss motivations. Among university and community women (Studies 1and 2), perceptions of a female-skewed sex ratio corresponded to greater intrasexual competitiveness, increased body dissatisfaction, and increased dieting inclinations. Among single women, assessments of a female-skewed sex ratio corresponded to perceptions of unfavorable mating prospects, increased romantic pressure to alter their appearance, and higher body dissatisfaction (Study 3). Studies 4 and 5 experimentally manipulated perceived sex ratio. Women in the female-skewed condition felt less satisfied with their weights and shapes, but only if they believed the manipulation (Study 4). In Study 5, using a within-subjects design, women who evaluated a male-skewed (vs. female-skewed) dating profile array subsequently desired to lose less weight. Findings suggest women's perceptions of their social environments may contribute to body image and dieting motivations.

Female intrasexual competitiveness interacts with body mass index to predict willingness to use a risky diet pill

Introduction

Previous research has highlighted the putative role of intrasexual competition (IC) in predicting women's body dissatisfaction, weight loss effort, and, at its extreme, eating disorders. However, extant research reporting on these links is limited by its exclusion of potential confounds, including psychopathologies such as depression. Moreover, it is presently unclear whether women higher in body mass index (BMI) may be more prone to the influence of IC in taking dieting risks.

Methods

To address these gaps in the literature, 189 young adult women completed measures of IC, depressive symptoms, willingness to use a risky diet pill, and had their height and weight measured.

Results

Results showed that IC interacted with BMI to predict willingness to use a risky diet pill, such that women high in both IC and BMI were most likely to take the risky diet pill. Further exploratory analyses considering potential directional links between BMI and depression supported mediating roles of depression (from BMI) and BMI (from depression) in predicting willingness to use a risky diet pill.

Discussion

Results suggest that links between IC and dieting risks may be moderated by women's BMI, and that these links hold when considering depressive symptoms. Future longitudinal research would benefit from a better understanding of the potential directional links between BMI, depression, and diet pill use.

Our Grandmothers' Legacy: Challenges Faced by Female Ancestors Leave Traces in Modern Women's Same-Sex Relationships

Investigations of women's same-sex relationships present a paradoxical pattern, with women generally disliking competition, yet also exhibiting signs of intrasexual rivalry. The current article leverages the historical challenges faced by female ancestors to understand modern women's same-sex relationships. Across history, women were largely denied independent access to resources, often depending on male partners' provisioning to support themselves and their children. Same-sex peers thus became women's primary romantic rivals in competing to attract and retain relationships with the limited partners able and willing to invest. Modern women show signs of this competition, disliking and aggressing against those who threaten their romantic prospects, targeting especially physically attractive and sexually uninhibited peers. However, women also rely on one another for aid, information, and support. As most social groups were patrilocal across history, upon marriage, women left their families to reside with their husbands. Female ancestors likely used reciprocal altruism or mutualism to facilitate cooperative relationships with nearby unrelated women. To sustain these mutually beneficial cooperative exchange relationships, women may avoid competitive and status-striving peers, instead preferring kind, humble, and loyal allies. Ancestral women who managed to simultaneously compete for romantic partners while forming cooperative female friendships would have been especially successful. Women may therefore have developed strategies to achieve both competitive and cooperative goals, such as guising their intrasexual competition as prosociality or vulnerability. These historical challenges make sense of the seemingly paradoxical pattern of female aversion to competition, relational aggression, and valuation of loyal friends, offering insight into possible opportunities for intervention.

An Evolutionary Perspective on Appearance Enhancement Behavior

Researchers have highlighted numerous sociocultural factors that have been shown to underpin human appearance enhancement practices, including the influence of peers, family, the media, and sexual objectification. Fewer scholars have approached appearance enhancement from an evolutionary perspective or considered how sociocultural factors interact with evolved psychology to produce appearance enhancement behavior. Following others, we argue that evidence from the field of evolutionary psychology can complement existing sociocultural models by yielding unique insight into the historical and cross-cultural ubiquity of competition over aspects of physical appearance to embody what is desired by potential mates. An evolutionary lens can help to make sense of reliable sex and individual differences that impact appearance enhancement, as well as the context-dependent nature of putative adaptations that function to increase physical attractiveness. In the current review, appearance enhancement is described as a self-promotion strategy used to enhance reproductive success by rendering oneself more attractive than rivals to mates, thereby increasing one's mate value. The varied ways in which humans enhance their appearance are described, as well as the divergent tactics used by women and men to augment their appearance, which correspond to the preferences of opposite-sex mates in a heterosexual context. Evolutionarily relevant individual differences and contextual factors that vary predictably with appearance enhancement behavior are also discussed. The complementarity of sociocultural and evolutionary perspectives is emphasized and recommended avenues for future interdisciplinary research are provided for scholars interested in studying appearance enhancement behavior.

The Development of Market-Driven Identities in Young People: A Socio-Ecological Evolutionary Approach

With the transition toward densely populated and urbanized market-based cultures over the past 200 years, young people's development has been conditioned by the ascendancy of highly competitive skills-based labor markets that demand new forms of embodied capital (e.g., education) for young people to succeed. Life-history analysis reveals parental shifts toward greater investment in fewer children so parents can invest more in their children's embodied capital for them to compete successfully. Concomitantly, the evolution of market-based capitalism has been associated with the rise of extrinsic values such as individualism, materialism and status-seeking, which have intensified over the last 40-50 years in consumer economies. The dominance of extrinsic values is consequential: when young people show disproportionate extrinsic relative to intrinsic values there is increased risk for mental health problems and poorer well-being. This paper hypothesizes that, concomitant with the macro-cultural promotion of extrinsic values, young people in advanced capitalism (AC) are obliged to develop an identity that is market-driven and embedded in self-narratives of success, status, and enhanced self-image. The prominence of extrinsic values in AC are synergistic with neuro-maturational and stage-salient developments of adolescence and embodied in prominent market-driven criterion such as physical attractiveness, displays of wealth and material success, and high (educational and extra-curricular) achievements. Cultural transmission of market-driven criterion is facilitated by evolutionary tendencies in young people to learn from older, successful and prestigious individuals (prestige bias) and to copy their peers. The paper concludes with an integrated socio-ecological evolutionary account of market-driven identities in young people, while highlighting methodological challenges that arise when attempting to bridge macro-cultural and individual development.

Compassion-focused therapy for body weight shame: A mixed methods pilot trial

Individuals with bigger bodies (body mass index greater than 30) often experience body weight shame and are at increased risk for mental health vulnerabilities such as depression and anxiety. To date, there have been no studies specifically designed and pilot tested to help with body weight shame for individuals with bigger bodies that do not have a diagnosed clinical condition. The aim of current study is to investigate the initial feasibility of compassion-focused therapy (CFT) as a 12-session group intervention for the reduction in body weight shame for individuals with bigger bodies. The study used a mixed method repeated measure design, with both quantitative and qualitative measures, to assess the initial feasibility of the CFT group-based intervention. Participants (N = 5) attended a 12-session/2-h group CFT programme aimed to directly target body weight shame by cultivating compassion. Measurements were conducted at three time points (pre-, post- and 3-month follow-up intervention). Results indicated that CFT had a positive impact on reducing body weight shame, increasing compassion and improving health-engaging behaviours. Qualitative feedback indicated the importance of the group dynamics to help with the de-shaming of body appearance for individuals. Results from this feasibility trial are promising, and future research using randomized controlled trial methodologies should be conducted to evaluate the effectiveness of CFT as a treatment option for body weight shame for individuals with bigger bodies.

Eating Disorders: An Evolutionary Psychoneuroimmunological Approach

Eating disorders are evolutionarily novel conditions. They lead to some of the highest mortality rates of all psychiatric disorders. Several evolutionary hypotheses have been proposed for eating disorders, but only the intrasexual competition hypothesis is extensively supported by evidence. We present the mismatch hypothesis as a necessary extension to the current theoretical framework of eating disorders. This hypothesis explains the evolutionarily novel adaptive metaproblem that has arisen when mating motives conflict with the large-scale and easy availability of hyper-rewarding but obesogenic foods. This situation is exacerbated particularly in those contemporary environments that are characterized by sedentary lifestyles, ever-present junk foods, caloric surplus and the ubiquity of social comparisons that take place via social media. Our psychoneuroimmunological model connects ultimate-level causation with proximate mechanisms by showing how the adaptive metaproblem between mating motives and food rewards leads to chronic stress and, further, to disordered eating. Chronic stress causes neuroinflammation, which increases susceptibility to OCD-like behaviors that typically co-occur with eating disorders. Chronic stress upregulates the serotonergic system and causes dysphoric mood in anorexia nervosa patients. Dieting, however, reduces serotonin levels and dysphoric mood, leading to a vicious serotonergic-homeostatic stress/starvation cycle whereby cortisol and neuroinflammation increase through stringent dieting. Our psychoneuroimmunological model indicates that between-individual and within-individual variation in eating disorders partially arises from (co)variation in gut microbiota and stress responsivity, which influence neuroinflammation and the serotonergic system. We review the advances that have been made in recent years in understanding how to best treat eating disorders, outlining directions for future clinical research. Current evidence indicates that eating disorder treatments should aim to reduce the chronic stress, neuroinflammation, stress responsivity and gut dysbiosis that fuel the disorders. Connecting ultimate causes with proximate mechanisms and treating biopsychosocial causes rather than manifest symptoms is expected to bring more effective and sophisticated long-term interventions for the millions of people who suffer from eating disorders.

Evolutionary Psychology of Eating Disorders: An Explorative Study in Patients With Anorexia Nervosa and Bulimia Nervosa

Prior research on non-clinical samples has lent support to the sexual competition hypothesis for eating disorders (SCH) where the drive for thinness can be seen as an originally adaptive strategy for women to preserve a nubile female shape, which, when driven to an extreme, may cause eating disorders. Restrictive versus impulsive eating behavior may also be relevant for individual differences in allocation of resources to either mating effort or somatic growth, reflected in an evolutionary concept called “Life History Theory” (LHT). In this study, we aimed to test the SCH and predictions from LHT in female patients with clinically manifest eating disorders. Accordingly, 20 women diagnosed with anorexia nervosa (AN), 20 with bulimia nervosa (BN), and 29 age-matched controls completed a package of questionnaires comprising measures for behavioral features and attitudes related to eating behavior, intrasexual competition, life history strategy, executive functioning and mating effort. In line with predictions, we found that relatively faster life history strategies were associated with poorer executive functioning, lower perceived own mate value, greater intrasexual competition for mates but not for status, and, in part, with greater disordered eating behavior. Comparisons between AN and BN revealed that individuals with BN tended to pursue a “fast” life history strategy, whereas people with AN were more similar to controls in pursuing a “slow” life history strategy. Moreover, intrasexual competition for mates was significantly predicted by the severity of disordered eating behavior. Together, our findings lend partial support to the SCH for eating disorders. We discuss the implications and limitations of our study findings.

The K-SF-42

The purpose of the present article is to propose an alternative short form for the 199-item Arizona Life History Battery (ALHB), which we are calling the K-SF-42, as it contains 42 items as compared with the 20 items of the Mini-K, the short form that has been in greatest use for the past decade. These 42 items were selected from the ALHB, unlike those of the Mini-K, making direct comparisons of the relative psychometric performance of the two alternative short forms a valid and instructive exercise. A series of secondary data analyses were performed upon a recently completed five-nation cross-cultural survey, which was originally designed to assess the role of life history strategy in the etiology of interpersonal aggression. Only data from the ALHB that were collected in all five cross-cultural replications were used for the present analyses. The single immediate objective of this secondary data analysis was producing the K-SF-42 such that it would perform optimally across all five cultures sampled, and perhaps even generalize well to other modern industrial societies not currently sampled as a result of the geographic breadth of those included in the present study. A novel method, based on the use of the Cross-Sample Geometric Mean as a criterion for item selection, was used for generating such a cross-culturally valid short form.

Borderline Personality Disorder: Why 'fast and furious'?

The term 'Borderline Personality Disorder' (BPD) refers to a psychiatric syndrome that is characterized by emotion dysregulation, impulsivity, risk-taking behavior, irritability, feelings of emptiness, self-injury and fear of abandonment, as well as unstable interpersonal relationships. BPD is not only common in psychiatric populations but also more prevalent in the general community than previously thought, and thus represents an important public health issue. In contrast to most psychiatric disorders, some symptoms associated with BPD may improve over time, even without therapy, though impaired social functioning and interpersonal disturbances in close relationships often persist. Another counterintuitive and insufficiently resolved question is why depressive symptoms and risk-taking behaviors can occur simultaneously in the same individual. Moreover, there is an ongoing debate about the nosological position of BPD, which impacts on research regarding sex differences in clinical presentation and patterns of comorbidity.In this review, it is argued that many features of BPD may be conceptualized within an evolutionary framework, namely behavioral ecology. According to Life History Theory, BPD reflects a pathological extreme or distortion of a behavioral 'strategy' which unconsciously aims at immediate exploitation of resources, both interpersonal and material, based on predictions shaped by early developmental experiences. Such a view is consistent with standard medical conceptualizations of BPD, but goes beyond classic 'deficit'-oriented models, which may have profound implications for therapeutic approaches.

Methodologically Sound: Evaluating the Psychometric Approach to the Assessment of Human Life History [Reply to ]

Copping, Campbell, and Muncer (2014) have recently published an article critical of the psychometric approach to the assessment of life history (LH) strategy. Their purported goal was testing for the convergent validation and examining the psychometric structure of the High-K Strategy Scale (HKSS). As much of the literature on the psychometrics of human LH during the past decade or so has emanated from our research laboratory and those of close collaborators, we have prepared this detailed response. Our response is organized into four main sections: (1) A review of psychometric methods for the assessment of human LH strategy, expounding upon the essence of our approach; (2) our theoretical/conceptual concerns regarding the critique, addressing the broader issues raised by the critique regarding the latent and hierarchical structure of LH strategy; (3) our statistical/methodological concerns regarding the critique, examining the validity and persuasiveness of the empirical case made specifically against the HKSS; and (4) our recommendations for future research that we think might be helpful in closing the gap between the psychometric and biometric approaches to measurement in this area. Clearly stating our theoretical positions, describing our existing body of work, and acknowledging their limitations should assist future researchers in planning and implementing more informed and prudent empirical research that will synthesize the psychometric approach to the assessment of LH strategy with complementary methods.

Social Rank, Rank-Related Life Events and Eating Pathology

BACKGROUND

This study explored the role of meaning in the link between stress and disordered eating, in particular focusing on social rank.

METHOD

Two hundred and eleven women completed measures of eating pathology, depression, social comparison and life events where life events were assessed in terms of general loss, threat, shame and loss of social status.

RESULTS

Events involving loss of social status were related to eating pathology but only in women reporting self-perceived low rank. Events that did not concern social status were unrelated to eating pathology.

DISCUSSION

Women who perceive themselves to be low social status appear vulnerable to events that concern their social status.

Methodologically sound: Evaluating the psychometric approach to the assessment of human life history [reply to Copping, Campbell, and Muncer, 2014]

Copping, Campbell, and Muncer (2014) have recently published an article critical of the psychometric approach to the assessment of life history (LH) strategy. Their purported goal was testing for the convergent validation and examining the psychometric structure of the High-K Strategy Scale (HKSS). As much of the literature on the psychometrics of human LH during the past decade or so has emanated from our research laboratory and those of close collaborators, we have prepared this detailed response. Our response is organized into four main sections: (1) A review of psychometric methods for the assessment of human LH strategy, expounding upon the essence of our approach; (2) our theoretical/conceptual concerns regarding the critique, addressing the broader issues raised by the critique regarding the latent and hierarchical structure of LH strategy; (3) our statistical/methodological concerns regarding the critique, examining the validity and persuasiveness of the empirical case made specifically against the HKSS; and (4) our recommendations for future research that we think might be helpful in closing the gap between the psychometric and biometric approaches to measurement in this area. Clearly stating our theoretical positions, describing our existing body of work, and acknowledging their limitations should assist future researchers in planning and implementing more informed and prudent empirical research that will synthesize the psychometric approach to the assessment of LH strategy with complementary methods.

Psychometrics and life history strategy: the structure and validity of the High K Strategy Scale

In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006) was distributed to a large British sample (n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

Psychometrics and Life History Strategy: The Structure and Validity of the High K Strategy Scale

In this paper, we critically review the conceptualization and implementation of psychological measures of life history strategy associated with Differential K theory. The High K Strategy Scale (HKSS: Giosan, 2006 ) was distributed to a large British sample ( n = 809) with the aim of assessing its factor structure and construct validity in relation to theoretically relevant life history variables: age of puberty, age of first sexual encounter, and number of sexual partners. Exploratory and confirmatory factor analyses indicated that the HKSS in its current form did not show an adequate statistical fit to the data. Modifications to improve fit indicated four correlated factors (personal capital, environmental stability, environmental security, and social capital). Later puberty in women was positively associated with measures of the environment and personal capital. Among men, contrary to Differential K predictions but in line with female mate preferences, earlier sexual debut and more sexual partners were positively associated with more favorable environments and higher personal and social capital. We raise concerns about the use of psychometric indicators of lifestyle and personality as proxies for life history strategy when they have not been validated against objective measures derived from contemporary life history theory and when their status as causes, mediators, or correlates has not been investigated.

Do human females use indirect aggression as an intrasexual competition strategy?

Indirect aggression includes behaviours such as criticizing a competitor's appearance, spreading rumours about a person's sexual behaviour and social exclusion. Human females have a particular proclivity for using indirect aggression, which is typically directed at other females, especially attractive and sexually available females, in the context of intrasexual competition for mates. Indirect aggression is an effective intrasexual competition strategy. It is associated with a diminished willingness to compete on the part of victims and with greater dating and sexual behaviour among those who perpetrate the aggression.