Fetching
Lumbar Curvature: A Novel Evolved Standard of Attractiveness
David Lewis et al.
Evolution and Human Behavior, forthcoming
Abstract:
This paper reports independent studies supporting the proposal that human standards of attractiveness reflect the output of psychological adaptations to detect fitness-relevant traits. We tested novel a priori hypotheses based on an adaptive problem uniquely faced by ancestral hominin females: a forward-shifted center of mass during pregnancy. The hominin female spine possesses evolved morphology to deal with this adaptive challenge: wedging in the third-to-last lumbar vertebra. Among ancestral women, vertebral wedging would have minimized the net fitness threats posed by hypolordosis and hyperlordosis, thereby creating selective pressures on men to prefer such women as mates. On this basis, we hypothesized that men possess evolved mate preferences for women with this theoretically optimal angle of lumbar curvature. In Study 1, as hypothesized, men’s attraction toward women increased as women’s lumbar curvature approached this angle. However, vertebral wedging and buttock mass can both influence lumbar curvature. Study 2 thus employed a forced-choice paradigm in which men selected the most attractive woman among models exhibiting the same lumbar curvature, but for different morphological reasons. Men again tended to prefer women exhibiting cues to a degree of vertebral wedging closer to optimum. This included preferring women whose lumbar curvature specifically reflected vertebral wedging rather than buttock mass. These findings reveal novel, theoretically anchored, and previously undiscovered standards of attractiveness.
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Veteran Status and Paid Sex Among American Men: Results from Three National Surveys
Andrew London & Janet Wilmoth
Archives of Sexual Behavior, forthcoming
Abstract:
Surprisingly little population-based, social scientific research directly examines the association between veteran status and ever paying for sex although there are theoretical reasons to expect that such an association might emerge across the life course. In this article, we examined the relationship between veteran status and ever paying for sex among American men who turned 18 years old between 1922 and 2010 using data from three independent national samples: Wave 1 of the 2005–2006 National Social Life, Health, and Aging Project (NSHAP); the 1992 National Health and Social Life Survey (NHSLS); and pooled data from the 1991, 1993, 1994, and 2010 General Social Survey (GSS). In all three datasets, we found that veterans were significantly more likely than non-veterans to report ever having paid for sex: rates across the three sub-studies ranged from 10.86 to 14.57 % among non-veterans and from 25.27 to 33.92 % among veterans. In multivariate models that controlled for demographic and early-life factors to the extent possible with available data, the odds of ever paying for sex were estimated to be 2.25–3.10 times higher among veterans than among non-veterans. In a supplemental analysis using data from the GSS, we found that longer duration of service was associated with an increased odds of ever paying for sex. While these results do not demonstrate a causal relationship between serving in the military and ever paying for sex, the strength and consistency of the findings provide compelling evidence of an association that is worthy of further theorizing and empirical investigation. There is considerable room for advancing knowledge related to the influence of military service on the initiation, maintenance, frequency, and timing of paid sexual relationships in relation to other life events.
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Sex-linked mating strategies diverge with a manipulation of genital salience
Adam Fetterman, Nicole Kruger & Michael Robinson
Motivation and Emotion, February 2015, Pages 99-103
Abstract:
Trivers (Sexual selection and the descent of man, Aldine-Atherton, Chicago, pp 136–179, 1972) proposed that evolutionary factors should favor divergent mating strategies for males versus females. Such differences may be less pronounced among human beings than other animals and social norms and sex roles are also pertinent influences. The present experiment (N = 133 college undergraduates, 74 female) sought to bypass some of these other influences. Participants were randomly assigned to a condition designed to increase attention to the genital region (a downward pointing arrow) or not (an upward pointing arrow). They then reported on their interest in short-term (e.g., a one-night stand) and long-term (e.g., a potential marital partner) mating opportunities. A theory-consistent three-way interaction occurred such that the genital salience manipulation primed a shorter-term reproductive strategy among men and a longer-term reproductive strategy among women. The results provide unique support for evolution-linked ideas about sex differences in the form of a role for bodily attention.
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Jeremy Uecker
Social Science Research, July 2015, Pages 59–71
Abstract:
Most examinations of sexual behavior ignore social context. Using panel data from the National Longitudinal Study of Freshmen, a panel study of 3,924 students at 28 selective colleges and universities, I examine how institutional and peer-group characteristics influence the incidence of sexual intercourse among students during their freshman year. Students who enter college as virgins are more likely to have sexual intercourse on campuses where women comprise a higher proportion of the campus population and on campuses that are more academically rigorous. Students who had sex prior to college are less likely to have sex in college when campuses are more residential. Moreover, having friends who value religion and partying affects the likelihood that a student will have sex irrespective of their prior virginity status. These findings highlight the importance of social context for sexual behavior among college students and in the general population.
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Do orgasms give women feedback about mate choice?
Gordon Gallup et al.
Evolutionary Psychology, November 2014, Pages 958-978
Abstract:
The current study represents a preliminary investigation of the extent to which female orgasm functions to promote good mate choices. Based on a survey of heterosexual female college students in committed relationships, how often women experienced orgasm as a result of sexual intercourse was related to their partner’s family income, his self-confidence, and how attractive he was. Orgasm intensity was also related to how attracted they were to their partners, how many times they had sex per week, and ratings of sexual satisfaction. Those with partners who their friends rated as more attractive also tended to have more intense orgasms. Orgasm frequency was highly correlated (r = .82) with orgasm intensity, and orgasm intensity was a marginally better predictor of sexual satisfaction than orgasm frequency. Sexual satisfaction was related to how physically attracted women were to their partner and the breadth of his shoulders. Women who began having sexual intercourse at earlier ages had more sex partners, experienced more orgasms, and were more sexually satisfied with their partners. We also identified an ensemble of partner psychological traits (motivation, intelligence, focus, and determination) that predicted how often women initiated sexual intercourse. Their partner’s sense of humor not only predicted his self-confidence and family income, but it also predicted women’s propensity to initiate sex, how often they had sex, and it enhanced their orgasm frequency in comparison with other partners.
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The low male voice is a costly signal of phenotypic quality among Bolivian adolescents
Carolyn Hodges-Simeon, Michael Gurven & Steven Gaulin
Evolution and Human Behavior, forthcoming
Abstract:
The human voice is one of the most conspicuous and dimorphic human secondary sexual characteristics; males’ low fundamental and formant frequencies barely overlap with females’. Researchers often assert that low male voices are costly signals of phenotypic quality; however, no evidence currently exists linking low voices with indicators of quality (i.e., health or physical condition) during the ages where the larynx develops to adult proportions. In the present study, we examine the relationships between condition, testosterone, and vocal parameters in 91 Bolivian peri-pubertal adolescent males. Condition is operationalized as immune function (based on secretory IgA) and energetic reserves (BMI-for-age residuals from Tsimane-specific growth curves, and body fat percentage), and “masculine” vocal parameters is operationalized as having low fundamental frequency, narrow formant position, and low fundamental-frequency variation. We target peri-pubertal individuals to capture variation in vocal parameters during the canalization period for vocal fold and vocal tract growth. Results indicate that males in better energetic condition have higher testosterone levels and lower voices, controlling for age. Further, testosterone mediates the relationship between condition and a lower voice (i.e., lower fundamental and formant frequencies). We suggest that testosterone plays a key mediating role in the causal pathway linking phenotypic condition to a “masculine” voice. Our results provide support for a costly-signal model of low men’s voices.
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David Puts et al.
Hormones and Behavior, forthcoming
Abstract:
Across human societies and many nonhuman animals, males have greater interest in uncommitted sex (more unrestricted sociosexuality) than do females. Testosterone shows positive associations with male-typical sociosexual behavior in nonhuman animals. Yet, it remains unclear whether the human sex difference in sociosexual psychology (attitudes and desires) is mediated by testosterone, whether any relationships between testosterone and sociosexuality differ between men and women, and what the nature of these possible relationships might be. In studies to resolve these questions, we examined relationships between salivary testosterone concentrations and sociosexual psychology and behavior in men and women. We measured testosterone in all men in our sample, but only in those women taking oral contraception (OC-using women) in order to reduce the influence of ovulatory cycle variation in ovarian hormone production. We found that OC-using women did not differ from normally-ovulating women in sociosexual psychology or behavior, but that circulating testosterone mediated the sex difference in human sociosexuality and predicted sociosexual psychology in men but not OC-using women. Moreover, when sociosexual psychology was controlled, men’s sociosexual behavior (number of sexual partners) was negatively related to testosterone, suggesting that testosterone drives sociosexual psychology in men and is inhibited when those desires are fulfilled. This more complex relationship between androgen and male sexuality may reconcile some conflicting prior reports.
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Birds of a “bad” feather flock together: The Dark Triad and mate choice
Peter Jonason, Minna Lyons & Alyson Blanchard
Personality and Individual Differences, May 2015, Pages 34–38
Abstract:
Previous research on the Dark Triad traits (i.e., Machiavellianism, psychopathy, and narcissism) has focused solely on the role the Dark Triad traits played in mate choice of actors. The current study (N = 336) extends this by manipulating the apparent levels of Dark Triad traits in targets and correlating mate choice in these targets with individual differences in the Dark Triad traits in actors. As expected, both sexes preferred partners low in the Dark Triad traits for long-term mating, while those high in these traits were preferred for one-night stands. However, women high in psychopathy considered the Dark Triad traits in potential male partners more physically attractive and desirable for an one-night stand, as well as a potential husband. Men who were high on psychopathy were likewise attracted to psychopathy in potential mothers. Our findings are discussed from an evolutionary personality paradigm.
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Sethu Karthikeyan & John Locke
Evolutionary Behavioral Sciences, January 2015, Pages 55-67
Abstract:
In a simulated speed dating context, 36 women were audio recorded as they verbally responded to an attractive male voice heard with its fundamental frequency (f₀) electronically raised or lowered. Women’s responses, recorded during high- and low-fertility phases of their menstrual cycles, were analyzed acoustically and evaluated for their attractiveness by 50 male listeners. As hypothesized, fertility increased ratings of attractiveness. Against our prediction, however, it lowered f₀, and the raised and lowered male voice exerted no effect on women’s f₀ or attractiveness ratings in either fertility phase. Results are discussed in relation to cycle-related changes in women’s mating preferences and behavior, context-induced changes in speech, and subtlety in potentially dual sexual strategies.
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Parental social status and intrasexual competitiveness among adolescents
Abraham Buunk, Gert Stulp & Johan Ormel
Evolutionary Psychology, November 2014, Pages 1022-1037
Abstract:
A study among 1,881 adolescents (52.3% girls) with a mean age of 19.1 years examined the effects of parental social status upon intrasexual competitiveness. Whereas females were consistently more intrasexually competitive the higher the socio-economic status of their parents, males with parents of the lowest socio-economic status tended to be more intrasexually competitive than those with parents of medium socio-economic status, and nearly as intrasexually competitive as those with parents of high socio-economic status. Only among adolescents with parents of low socio-economic status were males more intrasexually competitive than females. Among males and females, higher levels of intrasexual competitiveness were related to a higher family income, to a higher occupational status of the father as well as of the mother, and to a higher educational level of the mother. Only among females were higher levels of intrasexual competitiveness associated with a higher educational level of the father. Males whose fathers had only elementary education had a relatively high level of intrasexual competitiveness. The results are discussed in the context of the multifaceted nature of human status, and the potential relevance of intrasexual competitiveness for individuals of high versus low social status.
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The puzzling attractiveness of male shame
Alec Beall & Jessica Tracy
Evolutionary Psychology, January 2015, Pages 29-47
Abstract:
Two studies examined the mechanisms underlying North American women’s previously documented attraction to men displaying the nonverbal expression of shame (Tracy and Beall, 2011). In Study 1, American women at high-conception risk were found to be less attracted to men displaying shame compared to women at low-conception risk, suggesting that male shame displays indicate poor genetic fitness. In Study 2, Indian women were found to be less attracted to men displaying shame than American women, suggesting that American women’s tendency to find shame-displaying men attractive is likely due to local socio-cultural factors rather than to universal genetically encoded predispositions. Together, findings suggest that the attractiveness of male shame displays, previously documented in several North American samples, is best explained by cultural rather than biological factors.
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Yan Deng & Yong Zheng
Evolutionary Psychology, January 2015, Pages 89-105
Abstract:
Studies of humans and non-human animals indicate that females tend to change the likelihood of choosing a potential mate based on the decisions of other females; this is known as mate-choice copying. In a sample of both single and coupled women, we examined the influence of other women’s (model) mate-choice decisions, including mate acceptance and mate rejection, on participants’ attractiveness ratings of men (target) and willingness of mate selection. We also examined whether different types of relationships between the target men and the model women affected mate-choice copying. We found that both the single and coupled women showed mate-choice copying, but their response patterns differed. The significant effects for single women were dependent on a decrease in attractiveness ratings when they perceived the models’ mate rejection. However, the significant findings for coupled women relied on an increase in attractiveness ratings when they observed the models’ mate acceptance. Furthermore, the relationship status between the target men and the model women affected the magnitude of mate-choice copying effects for the single women. Specifically, they showed less mate-choice copying when the targets and models were in a committed romantic relationship than when in a temporary relationship.