Intimate Details
Kin Affiliation Across the Ovulatory Cycle: Females Avoid Fathers When Fertile
Debra Lieberman, Elizabeth Pillsworth & Martie Haselton
Psychological Science, forthcoming
Abstract:
A commonplace observation in humans is that close genetic relatives tend to avoid one another as sexual partners. Despite the growing psychological research on how antierotic attitudes develop toward relatives, few studies have focused on actual behavior. One prediction, stemming from parental investment theory, is that women should be more vigilant of reproduction-compromising behaviors, such as inbreeding, during times of peak fertility than during times of low fertility. Indeed, females of other species avoid interactions with male kin when fertile-but the corollary behavior in humans has yet to be explored. Here we fill this gap. Using duration and frequency of cell-phone calls, an objective behavioral measure that reflects motivations to interact socially, we show that women selectively avoid interactions with their fathers during peak fertility. Avoidance specifically targeted fathers, which rules out alternative explanations. These data suggest that psychological mechanisms underlying mating psychology regulate sexual avoidance behaviors, and in women they fluctuate according to fertility status.
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Dina Dosmukhambetova & Antony Manstead
Evolution and Human Behavior, forthcoming
Abstract:
People are motivated to self-present to their potential romantic partners. We hypothesized that due to the uncertainty of paternity, one of the self-presentational behaviors that human females engage in when they are motivated to attract a long-term mate is designed to communicate to prospective partners that they are likely to be faithful. In Study 1, we show that females in a long-term-romance mindset are less likely to agree to going to a concert with another female known to be unfaithful (cheater) than with a female known to have many sexual partners (player) or a non-flirtatious control female (control). Females in the long-term-romance mindset are also less willing to be the unfaithful female's friend and less willing to indicate that she is similar to them. In Study 2, we show that the effect is gender specific. In particular, we show that in the presence of a potential long-term partner, females (but not males) express more rejecting emotions towards a same-sex acquaintance who reveals a predilection to be unfaithful. These studies provide strong support for the role of uncertainty of paternity in the female self-presentational behaviors in the context of mate attraction.
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Ashley Hoben et al.
Evolutionary Psychology, November 2010, Pages 658-676
Abstract:
We propose that consanguineous marriages arise adaptively in response to high parasite prevalence and function to maintain coadapted gene complexes and associated local adaptation that defend against local pathogens. Therefore, a greater prevalence of inbreeding by consanguineous marriage is expected in geographical regions that historically have had high levels of disease-causing parasites. Eventually such marriages may, under the contemporary high movement of people with modern transportation, jeopardize the immunity of those who practice inbreeding as this leads to an increased susceptibility to novel pathogens. Therefore, a greater frequency of inbreeding is expected to predict higher levels of contemporary mortality and morbidity from infectious diseases. This parasite model of human inbreeding was supported by an analysis involving 72 countries worldwide. We found that historically high levels of pathogen prevalence were related positively to the proportion of consanguineous marriages, and that a higher prevalence of such marriages was associated with higher contemporary mortality and morbidity due to pathogens. Our study addresses plausible alternative explanations. The results suggest that consanguineous marriage is an adaptive consequence of historical pathogen ecologies, but is maladaptive in contemporary disease ecologies.
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Associations between Dopamine D4 Receptor Gene Variation with Both Infidelity and Sexual Promiscuity
Justin Garcia et al.
PLoS ONE, November 2010, e14162
Background: Human sexual behavior is highly variable both within and between populations. While sex-related characteristics and sexual behavior are central to evolutionary theory (sexual selection), little is known about the genetic bases of individual variation in sexual behavior. The variable number tandem repeats (VNTR) polymorphism in exon III of the human dopamine D4 receptor gene (DRD4) has been correlated with an array of behavioral phenotypes and may be predicatively responsible for variation in motivating some sexual behaviors, particularly promiscuity and infidelity.
Methodology/Principal Findings: We administered an anonymous survey on personal history of sexual behavior and intimate relationships to 181 young adults. We also collected buccal wash samples and genotyped the DRD4 VNTR. Here we show that individuals with at least one 7-repeat allele (7R+) report a greater categorical rate of promiscuous sexual behavior (i.e., having ever had a "one-night stand") and report a more than 50% increase in instances of sexual infidelity.
Conclusions/Significance: DRD4 VNTR genotype varies considerably within and among populations and has been subject to relatively recent, local selective pressures. Individual differences in sexual behavior are likely partially mediated by individual genetic variation in genes coding for motivation and reward in the brain. Conceptualizing these findings in terms of r/K selection theory suggests a mechanism for selective pressure for and against the 7R+ genotype that may explain the considerable global allelic variation for this polymorphism.
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Jeffrey Snyder et al.
Evolution and Human Behavior, forthcoming
Abstract:
Women's mate selection criteria can be expected to include a preference for men who can protect them and their offspring. However, aggressive dominance and physical formidability are not an unalloyed good in a partner; as such, men are likely to be coercive toward their mates. Accordingly, because of the potential costs of living with an aggressively dominant and physically formidable mate, a woman's preferences in this regard can be expected to vary as a function of the appraisal of her vulnerability to aggression - the more that a woman sees herself as potentially benefiting from protection, the more that she can be expected to favor aggressive dominance and physical formidability in a mate. Across three Internet-based studies of US women, we found evidence consistent with this perspective, such that women's fear of crime predicted her preference for long-term mates who are aggressively dominant and physically formidable.
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Mike Waller
Journal of Social, Evolutionary, and Cultural Psychology, May 2010, Pages 94-114
Abstract:
It is now known that in addition to their psychological and behavioural symptoms, chronic depressive illnesses have damaging effects on both the immune and cardiovascular systems. Given that similar patterns are found in other species, there is a need to determine how such seemingly disadvantageous mechanisms could have persisted over evolutionary timescales. This paper offers an answer by applying inclusive fitness theory to the process of mate selection. To mate selectors, the value of direct observation is limited by the phenotype/genotype disparity. Although it does not seem to have been previously suggested, there is evidence that natural selection has partially circumvented this limitation by favouring the use of the stockbreeding technique of obtaining additional genetic information from a candidate's close kin. One implication of this is that individuals much less well fitted than their kin can have a negative impact upon the reproductive success of their abler relatives. Indeed, the point could be reached at which the aggregate reputational damage they inadvertently cause imposes reproductive penalties across their kin group substantially in excess of their own likely reproductive contribution. Under such circumstances, as a form of damage control, inclusive fitness considerations would favour the emergence of autonomic mechanisms serving rapidly to eliminate the less well fitted individual. Severe depression, given how life-threatening its symptoms would have been in any imaginable Era of Evolutionary Adaption, could have evolved to bring this about. In this paper, literature relating to: mate choice among peacocks, an island population affected by a debilitating genetic disease, the stigmatisation of families of psychiatric patients, the determinants of self-esteem, and the psychological factors underpinning human health and happiness has been reviewed against four hypotheses derived what the author terms "stigma theory". Although much remains to be done, the initial findings are strongly supportive. Stigma theory's relevance to non-reciprocal altruism to unrelated others, social conformity and the current epidemic of depressive illness are discussed.
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Adult attachment and dating strategies: How do insecure people attract mates?
Claudia Chloe Brumbaugh & Chris Fraley
Personal Relationships, December 2010, Pages 599-614
Abstract:
When asked to choose among secure or insecurely attached partner prototypes, research shows that people tend to select secure individuals as their first choice. Despite this pattern, not everyone chooses secure partners in reality. The goal of this study was to examine the ways in which insecure individuals present themselves that might make them attractive to others. To achieve this goal, participants were led to believe that they were interacting with a possible date. That insecure individuals presented themselves as warm, engaging, and humorous people when communicating with potential mates were found. These findings suggest that insecure people have numerous dating tactics and positive qualities that they display to win over romantic partners.
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Reproductive strategies and relationship preferences associated with prestigious and dominant men
Daniel Kruger & Carey Fitzgerald
Personality and Individual Differences, forthcoming
Abstract:
Women prefer dominant men as short-term mates and prestigious men as long-term mates. People associate short-term mating with masculine male facial features and long-term mating with feminine male facial features. The present study found that people associate dominant men with masculine facial features and short-term mating strategies, and prestigious men with feminine facial features and long-term mating strategies. Both men and women prefer high-prestige men for social relationships. Women prefer high-prestige men for long-term romantic relationships, yet prefer high-dominance men for brief sexual affairs. Although men were generally accurate in predicting women's partner preferences, men overestimated the degree to which women would find the high-dominance man more attractive for all types of relationships.
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Drew Bailey, Kristina Durante & David Geary
Evolution and Human Behavior, forthcoming
Abstract:
We tested the hypothesis that men are particularly sensitive to individual differences in the attractiveness of women of the same mate value as themselves and less sensitive to variation among women of lower or higher mate value. We first assessed sensitivity to variation in women's attractiveness by asking men (n=148) to choose the more attractive of two photographs of the same target woman (n=116), photographed once at ovulation, when estrogen-a hormone that has been found to increase women's attractiveness-is known to be high, and once during a nonfertile phase of the cycle. Across all women, men did not rate the picture of the ovulating woman as more attractive (p>.10), but they did rate this picture as more attractive for women of similar mate value to themselves. When we increased the implicit costs of mate pursuit by presenting a photograph of a boyfriend before presenting the woman's photographs, men showed higher sensitivity to variation in the attractiveness of women of equal and lower mate value, and less sensitivity or preference for the nonovulating photograph for women of higher mate value. Furthermore, experimentally increasing men's self-perceived mate value by providing false "datability" feedback shifted their sensitivity to variation in the attractiveness of women of higher mate value than the men's baseline. The results suggest that men's mate searching is calibrated to the relative mate value of themselves and prospective mates and varies dynamically with the cost-benefit tradeoffs of pursuing such a relationship.
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Rejection Hurts: The Effect of Being Dumped on Subsequent Mating Efforts
Christine Stanik, Robert Kurzban & Phoebe Ellsworth
Evolutionary Psychology, November 2010, Pages 682-694
Abstract:
Many of the qualities that people seek in a long-term partner are not directly observable. As a consequence, information gathered through social learning may be important in partner assessment. Here, we tested the hypothesis that finding out potential partners were rejected by their last partner would negatively affect participants' desire to pursue a romantic relationship with them. Results support this hypothesis, and this effect was, as predicted, greater when the target was being evaluated for a potential long-term relationship compared to a sexual relationship. In a more exploratory vein, we tested the effect of the target having rejected their last partner and failing to disclose how their last relationship ended. These scenarios produced intriguing sex differences, such that men's ratings of women fell after learning she had rejected her last partner, but women's ratings of men increased after the same information was introduced. Failing to disclose information about a past relationship was unappealing to both men and women, though particularly so for women.
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Imbalanced Sex Ratios, Men's Sexual Behavior, and Risk of Sexually Transmitted Infection in China
Scott South & Katherine Trent
Journal of Health and Social Behavior, December 2010, Pages 376-390
Abstract:
China has been experiencing pronounced changes in its sex ratio, but little research has explored the consequences of these changes for sexual behavior and health. We merge data from the 1999-2000 Chinese Health and Family Life Survey with community-level data from the 1982, 1990, and 2000 Chinese censuses to examine the relationship between the local sex ratio and several dimensions of men's sexual behavior and sexual health. Multilevel logistic regression models show that, when faced with a relative abundance of age-matched women in their community, Chinese men are slightly less likely to have intercourse with commercial sex workers, but are more likely to engage in premarital noncommercial intercourse and to test positive for a sexually transmitted infection. These findings are consistent with hypotheses derived from demographic-opportunity theory, which suggests that an abundance of opposite-sex partners will increase the risk of early, frequent, and multi-partner sex and, through this, sexually transmitted infection risk.
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Michele Ybarra, Kimberly Mitchell, Merle Hamburger, Marie Diener-West & Philip Leaf
Aggressive Behavior, January/February 2011, Pages 1-18
Abstract:
Longitudinal linkages between intentional exposure to x-rated material and sexually aggressive behavior were examined among youth 10-15 year olds surveyed nationally in the United States. At Wave 1 in 2006, participants (n = 1,588) were queried about these exposures and outcomes in the preceding 12 months. Wave 2 data (n = 1,206) were collected approximately 12 months after Wave 1 and Wave 3 data (n = 1,159) were collected approximately 24 months after Wave 1. Thus, data for this project represent a 36-month time frame. A marginal model with generalized estimating equations was used to represent the population-average odds of sexually aggressive behavior over the 36 months as a function of exposure to x-rated material over the same time and to account for clustering in the data within person over time. An average of 5% of youth reported perpetrating sexually aggressive behavior and 23% of youth reported intentional exposure to x-rated material. After adjusting for other potentially influential proximal (i.e., sexual aggression victimization) and distal characteristics (e.g., substance use), we found that intentional exposure to violent x-rated material over time predicted an almost 6-fold increase in the odds of self-reported sexually aggressive behavior (aOR: 5.8, 95% CI: 3.2, 10.5), whereas exposure to nonviolent x-rated material was not statistically significantly related (aOR: 1.7, 95% CI: 0.94, 2.9). Associations were similar for boys and girls (boys nonviolent x-rated material aOR = 2.0, 95% CI: 0.8, 4.7; violent x-rated material aOR = 6.5, 95% CI: 2.7, 15.3; girls nonviolent x-rated material aOR = 1.2, 95% CI: 0.5, 3.2; violet x-rated material aOR = 6.1, 95% CI: 2.5, 14.8).
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Perceiving the facial correlates of sociosexuality: Further evidence
Lynda Boothroy, Catharine Cross, Alan Gray, Claire Coombes & Katie Gregson-Curtis
Personality and Individual Differences, February 2011, Pages 422-425
Abstract:
Certain physical traits are associated with individuals' tendency towards short-term sexual relationships (as assayed by the Sociosexual Orientation Inventory). Observers may be able to accurately detect sociosexuality at zero acquaintance. Here we seek to assess whether accurate zero-acquaintance judgements are based on an awareness of the general tendency towards risky behaviour rather than a specific judgement of sociosexuality. Results replicate previous findings that the faces of individuals with an unrestricted sociosexual orientation are: accurately identified as having unrestricted sociosexuality if female, more masculine if male, and more attractive if female. Furthermore, perception of Sociosexual Orientation Inventory (SOI) in female faces was not due to an awareness of general risk taking behaviour.
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Douglas Kirby, Tina Raine, Greg Thrush, Cora Yuen, Abby Sokoloff & Susan Potter
Perspectives on Sexual and Reproductive Health, December 2010, Pages 251-257
Context: Adolescent females often have questions or concerns about their contraceptive methods, and they may discontinue use if these questions are not answered. Little evidence exists on whether follow-up phone calls to address young women's concerns can help sustain contraceptive use.
Methods: Between 2005 and 2007, a total of 805 females aged 14-18 attending a reproductive health clinic in San Francisco were randomly assigned to receive either regular clinic services or regular clinic services plus nine follow-up phone calls over 12 months. The young women were surveyed at baseline and roughly six, 12 and 18 months later to measure condom and contraceptive use, rates of pregnancy and STDs, and other outcomes and mediators. Multiple linear and logistic regression repeated measures analyses were used to assess the program's effects.
Results: Clinic counselors completed only 2.7 calls per patient, and made 7.8 attempts for every completed call. Although contraceptive use increased from baseline to follow-up at six months in both groups, levels of condom and contraceptive use, and rates of pregnancy and STDs, did not differ between the intervention and control groups at any of the follow-up assessments. Moreover, the intervention did not improve clinic utilization or satisfaction or have consistent positive effects on participants' attitudes.
Conclusions: Reaching young women by phone after a clinic visit for contraception is challenging and does not appear to provide significant benefits beyond those provided by basic clinic services. More intensive interventions may be needed to markedly change adolescent sexual and contraceptive behavior.