Female Intrasexual Competition Research Articles

Mating competition among females: testing the distinction between natural and sexual selection in an insect.

In species where females compete for mates, the male often provides the female with resources in addition to gametes. A recently suggested definition of sexual selection proposed that if females only benefit from additional resources that come with each mating and not additional gametes, female intrasexual competition for mating opportunities would result in natural selection rather than sexual selection. The nuptial gift-giving bushcricket Kawanaphila nartee has dynamic sex roles and has been a textbook example of sexual selection acting on females via mating competition. We investigated whether females of this species gain fitness benefits from nuptial gifts, additional ejaculates or both by controlling the number of matings and whether the female was allowed to consume the nutritious gift (spermatophylax) at mating. We found that egg production per day of life increased with the number of additional matings, both with and without spermatophylax consumption, but consuming the spermatophylax had an additional positive effect on the number of eggs. These effects were particularly strong in females with shorter lifespans. We discuss how the recently suggested definition of sexual selection applies to nuptial-feeding insects and conclude that both natural and sexual selections influence mating competition in K. nartee females.

Perceptions of Income Inequality and Women's Intrasexual Competition.

Income inequality has been empirically linked to interpersonal competition and risk-taking behaviors, but a separate line of findings consistently shows that individuals have inaccurate perceptions of the actual levels of income inequality in society. How can inequality be both consistently misperceived and yet a reliable predictor of behavior? The present study extends both these lines of research by evaluating if the scope of input used to assess income inequality (i.e., at the national, state, county, or postal code level) can account for perception discrepancies and if actual/perceived inequality is associated with female intrasexual competition. Female participants recruited online from the general US population (n = 691) provided demographic information, measures of perceived income inequality, and measures of intrasexual competition attitudes and behavior. Actual and perceived income inequality (at any level) did not predict negative attitudes toward other women or female weighting of physical appearance as a desirable trait. Perceived income inequality and actual county-level inequality was, however, predictive of female competition in the form of self-sexualization clothing choice. Further analyses found that age and importance placed on physical attractiveness also predicted women's clothing choices. Perceptions of income inequality were predicted not by actual Gini indices, but by beliefs about the levels of poverty and income gaps. These results highlight the importance of better understanding the proximate cues by which people perceive environmental features such as inequality, and how those cues are used to adjust interpersonal behaviors.

Off with her hair: Intrasexually competitive women advise other women to cut off more hair

Intrasexual competition between women is often covert, and targets rivals' appearance. Here we investigate appearance advice as a vector for female intrasexual competition. Across two studies (N = 192, N = 258) women indicated how much hair they would recommend hypothetical clients have cut off in their hypothetical salon. Clients varied in their facial attractiveness (depicted pictorially), the condition of their hair, and how much hair they wished to have cut off. Participants also provided self-report measures of their own mate value and intrasexual competitiveness. In both studies, participants' intrasexual competitiveness positively predicted how much hair they recommended clients have cut off, especially when the hair was in good condition and the clients reported wanting as little as possible cut off – circumstances wherein cutting off too much hair is most likely to indicate sabotage. Considering data across both collectively, women tended to recommend cutting the most hair off clients they perceived to be as attractive as themselves. These data suggest that just like mating, intrasexual competition may be assortative with respect to mate value. They also demonstrate that competitive motives can impact female-female interactions even in scenarios which feature no prospective mates, and are nominally unrelated to mate guarding or mating competition.

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.

Women's Romantic Jealousy Predicts Risky Appearance Enhancement Effort.

Human appearance enhancement effort has recently been considered from an evolutionary perspective as an adaptive and sexually dimorphic strategy for effective female intrasexual and intersexual competition. Most writing and research on the topic to date has focused on appearance enhancement as a means of mate attraction, with relatively less research examining its role in mate retention. The present study considered whether romantic jealousy, as a negative emotion experienced in response to perceived threat to a desired relationship, predicts costly and/or risky appearance enhancement independent of the closely related emotion of envy. In a sample of 189 undergraduate women, results showed that romantic jealousy and dispositional envy were positively correlated with one another. Results further demonstrated that romantic jealousy predicted women's positive attitude toward cosmetic surgery, willingness to use a one-week free tanning membership, willingness to use a risky diet pill, and intent on spending a greater proportion of their income on appearance enhancement, but not intended use of facial cosmetics. Results held independent of participants' dispositional envy, suggesting that romantic jealousy is a unique predictor of women's efforts at enhancing their physical appearance, which could extend into costly and physically risky mate retention efforts.

Female intrasexual competition is affected by the sexual orientation of the target and the ovulatory cycle.

Female intrasexual competition is affected by the sexual orientation of the target and the ovulatory cycle.

The role of sexual selection in flowering plant origin and evolution and the potential significance of female competition and selection in ovules

Abstract Ever since Erasmus and Charles Darwin laid down the foundations of the concept, sexual selection has largely been regarded as a matter of male competition and female selection. While their role in plant evolution and the elusive origin of flowering plants has largely been neglected in contrast to the situation with animals, there is a growing body of evidence accumulated over the past 50 years supporting the hypothesis that, together with the flower and the carpel, increased pollination has led to an intensification of the competition between the fittest (and faster) pollen tubes and their selection by the surrounding maternal tissue. In contrast, the potential role of female competition was historically seldom considered but started to re-emerge a decade ago in both animal and plant evolution. Here, I review a large body of the vast embryological literature to re-evaluate unusual developmental traits in the plant female germline, traditionally considered as teratological occurrences of mere systematic interest, in the light of the current phylogenetic framework for flowering plants. After a summary of the basic tenets of sexual selection and the role of male competition and maternal selection in shaping plant evolution and diversity, I show how recent insights into the deepest nodes of flowering plant phylogeny and confirmation of their systematic relationships over the past 30 years have led to major shifts in our understanding of the reproductive biology of their most recent common ancestor. I also show that a re-evaluation of these unusual developmental traits in the female germline, especially in early-diverging lineages of flowering plants, may potentially be correlated with some floral structural traits. On the basis of these results, I argue that there is circumstantial evidence for mechanisms of female intrasexual competition and selection in individual ovules of flowering plants that are similar to those between pollen tubes competing inside the carpel. I also argue that although they may have evolved independently multiple times in unrelated lineages, they could also be the ‘burning embers’ of plesiomorphic traits that would have been largely selected against after the evolution of their most recent common ancestor.

Supplemental Material for Female Intrasexual Competition Is Affected by the Sexual Orientation of the Target and the Ovulatory Cycle

Supplemental Material for Female Intrasexual Competition Is Affected by the Sexual Orientation of the Target and the Ovulatory Cycle

Influence of operational sex ratio and male age on mating competition intensity in reindeer (Rangifer tarandus)

The operational sex ratio (OSR), the ratio of sexually active males to sexually receptive females, is one of the main measures used to predict the intensity and direction of mating competition, influencing the opportunity for sexual selection. Here, we conducted the first experimental study to investigate how OSR and male age impacts the intensity of mating competition in reindeer (Rangifer tarandus), under semi-natural conditions during the rut. We manipulated OSR on two levels in two enclosures, a female biased treatment (3♂:6♀ = OSR 0.5) and a sex balanced treatment (3♂:3♀ = OSR 1), over 2 years with males from two age groups, and with females of various ages. We found some support for prevailing OSR theory, notably with female intrasexual competition occurring at lower frequencies in OSR 1 than OSR 0.5, and male intrasexual competition occurring at higher frequencies in the older male age group. Courtship behaviour was found to occur at higher frequencies in OSR 1 than OSR 0.5; however, there was no effect of male age. To successfully pass on genes to the next generation, one needs access to mates and winning a competitive bout is not always indicative of successfully accomplishing gene flow. Studies on OSR have the potential to help us understand the drivers behind sexual competition and how best to predict breeding outcomes during a rut.

Friendship, Mating, and Reputation in U.S. College Sororities: Exploring Female Intrasexual Competition and Cooperation

Friendship, Mating, and Reputation in U.S. College Sororities: Exploring Female Intrasexual Competition and Cooperation

Influence of operational sex ratio and male age on mating competition intensity in reindeer (Rangifer tarandus)

The operational sex ratio (OSR), the ratio of sexually active males to sexually receptive females, is one of the main measures used to predict the intensity and direction of mating competition, influencing the opportunity for sexual selection. Here, we conducted the first experimental study to investigate how OSR and male age impacts the intensity of mating competition in reindeer (Rangifer tarandus), under semi-natural conditions during the rut. We manipulated OSR on two levels in two enclosures, a female biased treatment (3♂:6♀ = OSR 0.5) and a sex balanced treatment (3♂:3♀ = OSR 1), over 2 years with males from two age groups, and with females of various ages. We found some support for prevailing OSR theory, notably with female intrasexual competition occurring at lower frequencies in OSR 1 than OSR 0.5, and male intrasexual competition occurring at higher frequencies in the older male age group. Courtship behaviour was found to occur at higher frequencies in OSR 1 than OSR 0.5; however, there was no effect of male age. To successfully pass on genes to the next generation, one needs access to mates and winning a competitive bout is not always indicative of successfully accomplishing gene flow. Studies on OSR have the potential to help us understand the drivers behind sexual competition and how best to predict breeding outcomes during a rut.

An intergenerational androgenic mechanism of female intrasexual competition in the cooperatively breeding meerkat

Female intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testosterone, but in females, there has been little systematic investigation of androgen-mediated behaviour within and across generations. In 22 clans of wild meerkats (Suricata suricatta), we show that matriarchs 1) express peak androgen concentrations during late gestation, 2) when displaying peak feeding competition, dominance behaviour, and evictions, and 3) relative to subordinates, produce offspring that are more aggressive in early development. Late-gestation antiandrogen treatment of matriarchs 4) specifically reduces dominance behaviour, is associated with infrequent evictions, decreases social centrality within the clan, 5) increases aggression in cohabiting subordinate dams, and 6) reduces offspring aggression. These effects implicate androgen-mediated aggression in the operation of female sexual selection, and intergenerational transmission of masculinised phenotypes in the evolution of meerkat cooperative breeding.

Female Intrasexual Competition and Its Link to Menopausal Stage, Sex Hormone Levels, and Personality Characteristics.

Background: Female intrasexual competition (ISC) represents a unique form of social interaction. It describes behaviors primarily applied to enhance a woman's ability to outcompete other women. Previous research suggests that female ISC is influenced by personality characteristics and sex hormones. Although these factors most likely interact to predict female ISC, no previous study has investigated those factors in parallel in order to link theories from social psychology and biology. Women at the end of the reproductive lifespan represent the ideal study population, as they allow for a controlled hormonal environment.Materials and Methods: Healthy pre- (N = 53) and postmenopausal (N = 56) women were classified according to the Stages of Reproductive Aging Workshop (STRAW+10) criteria. In the follicular phase (for premenopausal women) or on a random day (for postmenopausal women), questionnaires were administered to assess the general tendency to compete intrasexually and the tendency to compete on appearance, attention/interpersonal success, and competence. Additionally, personality characteristics (neuroticism, extraversion, openness, agreeableness, conscientiousness, and self-esteem) were assessed. On the same day, each subject provided an 8 a.m. saliva sample for estradiol, testosterone, progesterone, and dehydroepiandrosterone sulfate. T-tests tested for between-group differences and separate multiple linear regression models tested for an effect of continuous hormone levels and personality characteristics on ISC. Further models were run, testing for an interaction with menopausal stage.Results: No group differences in ISC were evident (all p > 0.05). In premenopausal women, estradiol levels positively predicted the competition for attention (β = 2.103, p = 0.022). In postmenopausal women, self-esteem predicted the tendency to compete overall (β = −0.208, p < 0.001), on appearance (β = −0.061, p = 0.01), on competence (β = −0.087, p < 0.001), and on attention/interpersonal success (β = −0.060, p = 0.01).Discussion: These results, though cross-sectional, suggest that women continue to compete intrasexually in postmenopause, giving rise to new questions about the function of female ISC. If confirmed, the findings will indicate that hormones guide competitiveness in fertile women, whereas self-esteem accounts for individual differences in competitiveness post-reproduction. Particularly the function of postmenopausal ISC warrants further investigation.

Friend or Foe? Mate Presence and Rival Type Influence Clothing-Based Female Intrasexual Competition

Evolutionary psychologists have brought attention to women’s intrasexual competition in ways that traditional perspectives have overlooked. Whereas most researchers have thus far focused on exploratory investigations of this phenomenon, we experimentally manipulated contextual factors that could affect intrasexual competition (e.g., rival type, presence of a potential mate) and assessed competitive behavior via clothing choice. Across two studies, female MTurk users (NStudy1 = 131; NStudy2 = 262) read a vignette describing an upcoming party then chose an outfit they would wear to that party from a set of clothing items that had been pre-rated on sexiness and revealingness by a separate sample (N = 100). Within the vignette, we inserted participant-provided initials to manipulate the presence of a crush and the familiarity and attractiveness of their female party companion. Unexpectedly, we found a significant difference between outfit ratings for separates compared with dresses, so we incorporated this into our model. In study 1, among women who chose dresses, those who imagined attending the party with a more attractive acquaintance and their crush present chose more attractive outfits than women in the less attractive acquaintance condition. However, no such pattern was found for women who chose separates or women in the close friend condition. In study 2, a pre-registered direct replication showed that women in the acquaintance condition chose more attractive outfits than women in the close friend condition, but only in the crush present condition. Women’s intrasexual competition mechanisms appear cost-sensitive and only prompt competitive tactics when rivals are particularly threatening.

“Sneering Civility”: Female Intrasexual Competition for Mates in Jane Austin’s Novels

“Sneering Civility”: Female Intrasexual Competition for Mates in Jane Austin’s Novels

Sexual selection and its evolutionary consequences in female animals.

For sexual selection to act on a given sex, there must exist variation in the reproductive success of that sex as a result of differential access to mates or fertilisations. The mechanisms and consequences of sexual selection acting on male animals are well documented, but research on sexual selection acting on females has only recently received attention. Controversy still exists over whether sexual selection acts on females in the traditional sense, and over whether to modify the existing definition of sexual selection (to include resource competition) or to invoke alternative mechanisms (usually social selection) to explain selection acting on females in connection with reproduction. However, substantial evidence exists of females bearing characters or exhibiting behaviours that result in differential reproductive success that are analogous to those attributed to sexual selection in males. Here we summarise the literature and provide substantial evidence of female intrasexual competition for access to mates, female intersexual signalling to potential mates, and postcopulatory mechanisms such as competition between eggs for access to sperm and cryptic male allocation. Our review makes clear that sexual selection acts on females and males in similar ways but sometimes to differing extents: the ceiling for the elaboration of costly traits may be lower in females than in males. We predict that current and future research on female sexual selection will provide increasing support for the parsimony and utility of the existing definition of sexual selection.

Measuring female intrasexual competition by the scale for intrasexual competition: a validation of the German version.

Competitive behaviour amongst members of the same sex is termed intrasexual competition. The tendency to engage in such competition appears to be strongly related to stable individual characteristics such as personality traits. Additionally, recent studies have revealed transient fluctuations in competitiveness according to the female menstrual cycle. To date, no German questionnaire exists to measure intrasexual competition. Our first study aimed to translate and validate the Intrasexual Competition Scale (ICS) by Buunk and Fisher (J Evol Psychol 7:37-48, 2009) in a population of healthy Swiss females (n = 241). Our second study applied the validated German ICS in a group of healthy, regularly cycling females (n = 49) in order to examine possible associations between the menstrual cycle phase and ICS scores. The psychometric properties suggest that the German ICS is a reliable and valid tool to assess individual differences in female intrasexual competition. Furthermore, our second study demonstrated that on average, women showed higher intrasexual competition scores when tested in the late follicular phase (M = 35.77 ± SD = 12.03) compared to the mid-luteal phase (M = 30.93 ± SD = 10.20). Our studies support previous findings of an association between ICS scores and relatively stable individual characteristics such as personality traits. Furthermore, our research endorses the assumption of cycle-dependent fluctuations in intrasexual competition. Future research should clarify the precise mechanisms underlying these findings and include biomarkers such as oestrogen and testosterone.

Competitive reputation manipulation: Women strategically transmit social information about romantic rivals

Researchers have suggested that women compete with same-sex peers using indirect social tactics. However, the specific predictors and mechanisms of this form of female intrasexual competition are less well understood. We propose that one mechanism by which women harm rivals' social opportunities is through selectively transmitting reputation-relevant social information. Moreover, we contend that this behavior is designed to undermine the romantic and social appeal of same-sex romantic rivals who are perceived to be threatening. Evidence from five studies suggests that women's dissemination of social information is strategic and reliably predicted by various cues of romantic rival threat: attempts at mate poaching (Study 1), physical attractiveness (Studies 2 and 3), and provocative clothing (Studies 4 and 5). Women strategically harmed and failed to enhance the reputations of other women who threatened their romantic prospects directly (by flirting with their romantic partners) and indirectly (by being attractive or provocatively dressed). Women's dispositional levels of competitiveness also predicted their information transmission: highly competitive women (both generally and in romantic domains specifically) disclosed more reputation-damaging information than did less competitive women. Furthermore, women transmitted reputation-harming information about female targets independent of how much they explicitly liked those targets, suggesting a disconnect between women's intentions and their gossip behavior. Irrespective of the gossiper's intentions, pilot data confirmed that social harm is likely to befall the women targeted by the transmission of reputation-damaging social information.

Negative Effects of Makeup Use on Perceptions of Leadership Ability Across Two Ethnicities

Cosmetics alter social perceptions, and prior work suggests that cosmetic use may aid female intrasexual competition, making women appear more dominant to other women but more prestigious to other men. It is unclear whether these findings reflect general improvements in perceptions of traits related to women's dominance or if they are specific to mating contexts only. Here, across two ethnicities, we examined effects of cosmetics used for a social night out on perceptions of women's leadership ability, a trait that denotes competence/high status outside of mating contexts. Participants of African and Caucasian ethnicity judged faces for leadership ability where half of the trials differed in ethnicity (own- vs. other-ethnicity face pairs) and the subtlety of the color manipulation (50% vs. 100%). Regardless of the participant's sex or ethnicity, makeup used for a social night out had a negative effect on perceptions of women's leadership ability. Our findings suggest that, in prior work, women are afforded traits related to dominance, as makeup enhances perceptions of traits that are important for successful female mating competition but not other components of social dominance such as leadership.

I wear Prada, because I want to.

: Previous studies on luxury consumption indicated that women may use luxury consumption as a self-promotion strategy during within-sex competitions, as these luxuries improve their advantages against same sex rivals for mates. Many of these studies rely on costly signalling and intra-sexual competition theory, and they suggest female intra-sexual competition in a mate attraction context triggers women’s spending on luxury products. The focus of this paper is to understand the gender-related motivations, specifically for female consumers in the luxury market and to compare and contrast the new findings with the previous studies. The finding of this study demonstrates other motives in female luxury consumer behaviour rather than relationship, self-enhancement and competition.