The Morning after the Night Before

Benefits to females of short-term mating have recently been identified, and it has been suggested that women have evolved adaptations for this strategy. One piece of evidence supporting such a female adaptation would be that women find the experience of a one-night stand as affectively positive as men. Individuals (N = 1,743) who had experienced a one-night stand were asked to rate aspects of their “morning after” feelings (six positive and six negative). Women were significantly more negative and less positive than men. Although women did not especially view these relationships as a prelude to long-term relationships, they felt greater regret than men about having been “used.” Extra-pair copulations were rated more negatively, but not less positively, than singles’ experiences. There was no interaction between gender and mated status on positivity or negativity. Although, in terms of subsequent affective response, women do not seem well adapted to casual sexual encounters, it may be important to distinguish impelling sexual motivation preceding intercourse from later evaluations of the event. Menstrual cycle changes may also be important in altering the strength and target of sexual motivation.     

Changes in Sleep Time and Sleep Quality across the Ovulatory Cycle as a Function of Fertility and Partner Attractiveness

Research suggests that near ovulation women tend to consume fewer calories and engage in more physical activity; they are judged to be more attractive, express greater preferences for masculine and symmetrical men, and experience increases in sexual desire for men other than their primary partners. Some of these cycle phase shifts are moderated by partner attractiveness and interpreted as strategic responses to women''s current reproductive context. The present study investigated changes in sleep across the ovulatory cycle, based on the hypothesis that changes in sleep may reflect ancestral strategic shifts of time and energy toward reproductive activities. Participants completed a 32-day daily diary in which they recorded their sleep time and quality for each day, yielding over 1,000 observations of sleep time and quality. Results indicated that, when the probability of conception was high, women partnered with less attractive men slept more, while women with more attractive partners slept less.     

Intersexual conflict across women's ovulatory cycle

A growing literature shows that the features women find particularly attractive in men vary across the ovulatory cycle. Women furthermore appear to more frequently report attraction to men other than primary partners when they are fertile in their cycle than in the infertile luteal phase. Previous studies have shown that men are more vigilant of or attentive to their primary partners during the fertile phase compared to the luteal phase. This study had several aims: First, to replicate and extend previous findings concerning men's vigilance of partners using male as well as female reports of men's behavior; second, to examine changes in women's behavior toward partners across the cycle; third, to examine ways in which women resist men's attempts to mate-guard across the cycle. Results indicate that (a) men are particularly self-assertive toward partners when their partners are fertile; (b) similarly, women are especially self-assertive toward partners when they are fertile; (c) women report engaging in more behaviors that resist male vigilance and mate guarding when they are fertile, especially in ways that are unobservable to male partners; and (d) these effects are especially strong when women themselves report greater attraction to men other than partners when they are fertile, compared to the luteal phase.     

Height and reproductive success in a cohort of british men

Two recent studies have shown a relationship between male height and number of offspring in contemporary developed-world populations. One of them argues as a result that directional selection for male tallness is both positive and unconstrained. This paper uses data from a large and socially representative national cohort of men who were born in Britain in March 1958. Taller men were less likely to be childless than shorter ones. They did not have a greater mean number of children. If anything, the pattern was the reverse, since men from higher socioeconomic groups tended to be taller and also to have smaller families. However, clear evidence was found that men who were taller than average were more likely to find a long-term partner, and also more likely to have several different long-term partners. This confirms the finding that tall men are considered more attractive and suggests that, in a noncontracepting environment, they would have more children. There is also evidence of stabilizing selection, since extremely tall men had an excess of health problems and an increased likelihood of childlessness. The conclusion is that male tallness has been selected for in recent human evolution but has been constrained by developmental factors and stabilizing selection on the extremely tall. The National Child Development Study is carried out by the researchers of the Centre for Longitudinal Studies, Institute of Education, London. The data are housed at the Data Archive of the University of Essex, from where they were obtained under license for the present study. I am grateful to Paul Preece for his assistance with data processing, and to Benjamin Campbell and two anonymous referees for invaluable advice which has, I hope, improved the quality of this paper. Daniel Nettle is lecturer in biological psychology at the Open University. With a first degree in psychology and a Ph.D. in biological anthropology, his work has been concerned with the application of evolutionary models to such topics as language (e.g., Linguistic Diversity, Oxford University Press, 1999) and individual differences (Strong Imagination, Oxford University Press, 2001).     

If You’ve Got It,Flaunt It: Humans Flaunt Attractive Partners to Enhance Their Status and Desirability

Mating decisions are influenced by conspecifics’ mate choices in many species including humans. Recent research has shown that women are more attracted to men with attractive putative partners than those with less attractive partners. We integrate these findings with traditional accounts of social signaling and test five hypotheses derived from it. In our study, 64 men and 75 women were paired with attractive and unattractive opposite-sex putative partners and asked whether they would prefer to give surveys to peers or to older adults. Consistent with predictions, both men and women wanted to show off (flaunt) attractive partners by administering surveys to peers and both men and women wanted to hide (conceal) unattractive partners from peers by administering surveys to older adults. These decisions were mediated by how participants expected others to evaluate their status and desirability when they administered the surveys, consistent with partners serving a social signaling function in humans.     

Preferences for masculinity in male bodies change across the menstrual cycle

In human females cyclic shifts in preference have been documented for odour and physical and behavioral male traits. Women prefer the smell of dominant males, more masculine male faces and men behaving more dominantly when at peak fertility than at other times in their menstrual cycle. Here we examine variation in preferences for body sexual dimorphism. Across two studies, both between- and within-participant, we show that women prefer greater masculinity in male bodies at times when their fertility is likely highest, in the follicular phase of their cycle. Shifts were seen when rating for a short-term but not when rating for a long-term relationship. In line with studies showing similar effects for facial sexual dimorphism, we also show that women prefer greater masculinity when they think themselves attractive than when they think themselves less attractive. These results indicate that women's preferences for sexual dimorphism in male bodies follow a similar pattern as found for sexual dimorphism and dominance in other domains and such differences in preference may serve a similar function. Cyclic preferences could influence women to select partners when most likely to become pregnant that possess traits that may be most likely to maximize their offspring's quality via attraction to masculinity or serve to help acquire investment via attraction to femininity.     

An Analysis of the Matching Hypothesis in Networks

The matching hypothesis in social psychology claims that people are more likely to form a committed relationship with someone equally attractive. Previous works on stochastic models of human mate choice process indicate that patterns supporting the matching hypothesis could occur even when similarity is not the primary consideration in seeking partners. Yet, most if not all of these works concentrate on fully-connected systems. Here we extend the analysis to networks. Our results indicate that the correlation of the couple’s attractiveness grows monotonically with the increased average degree and decreased degree diversity of the network. This correlation is lower in sparse networks than in fully-connected systems, because in the former less attractive individuals who find partners are likely to be coupled with ones who are more attractive than them. The chance of failing to be matched decreases exponentially with both the attractiveness and the degree. The matching hypothesis may not hold when the degree-attractiveness correlation is present, which can give rise to negative attractiveness correlation. Finally, we find that the ratio between the number of matched couples and the size of the maximum matching varies non-monotonically with the average degree of the network. Our results reveal the role of network topology in the process of human mate choice and bring insights into future investigations of different matching processes in networks.     

Men's facial masculinity predicts changes in their female partners' sexual interests across the ovulatory cycle,whereas men's intelligence does not

A substantial body of work demonstrates that women's mate preferences change across the ovulatory cycle. When fertile in their cycles, women are especially attracted to masculine features (e.g., faces, voices, bodies), socially dominant behavior, and male scents associated with body symmetry and social dominance. Women may also find intelligent men particularly attractive when fertile, though findings are mixed. Related research shows that, on average, romantically-involved women report stronger sexual attraction to men other than their pair-bond partners, but not partners, when fertile, and especially when their partners lack features fertile women prefer (e.g., symmetry). In the current study, we examined whether women's patterns of sexual interests across the cycle are similarly moderated by partners' facial masculinity, facial attractiveness, and intelligence. Results revealed predicted effects of male partners’ facial masculinity but none for partners’ intelligence. Facial attractiveness may have effects, but we find no evidence that it does so independently of facial masculinity.     

Error Management Theory and biased first impressions: How do people perceive potential mates under conditions of uncertainty?

People must make inferences about a potential mate's desirability based on incomplete information. Under such uncertainty, there are two possible errors: people could overperceive a mate’s desirability, which might lead to regrettable mating behavior, or they could underperceive the mate’s desirability, which might lead to missing a valuable opportunity. How do people balance the risks of these errors, and do men and women respond differently? Based on an analysis of the relative costs of these two types of error, we generated two new hypotheses about biases in initial person perception: the Male Overperception of Attractiveness Bias (MOAB) and the Female Underperception of Attractive Bias (FUAB). Participants (N = 398), who were recruited via social media, an email distribution list, and snowball sampling, rated the attractiveness of unfamiliar opposite-sex targets twice: once from a blurred image, and once from a clear image. By randomizing order of presentation (blurred first vs. clear first), we isolated the unique effects of uncertainty—which was only present when the participant saw the blurred image first. As predicted, men overperceived women's attractiveness, on average. By contrast, as predicted, women underperceived men's attractiveness, on average. Because multiple possible decision rules could produce these effects, the effects do not reveal the algorithm responsible for them. We explicitly addressed this level of analysis by identifying multiple candidate algorithms and testing the divergent predictions they yield. This suggested the existence of more nuanced biases: men overperceived the attractiveness of unattractive (but not attractive) women, whereas women underperceived the attractiveness of attractive (but not unattractive) men. These findings highlight the importance of incorporating algorithm in analyses of cognitive biases.     

The association of three indicators of developmental instability with mating success in humans

Developmental instability (DI) has been proposed to relate negatively to aspects of evolutionary fitness, like mating success. One suggested indicator is fluctuating asymmetry (FA), random deviations from perfect symmetry in bilateral bodily traits. A meta-analytically robust negative association between FA and number of lifetime sexual partners has been previously shown in men and women. We examined the relationship between bodily FA across twelve traits and indicators of quantitative mating success in 284 individuals (141 males, age 19–30 years). Two further indicators of DI, minor physical anomalies (MPAs) and asymmetry in palmar atd angles, were also assessed. For men, no significant associations were detected, whereas for women, unexpected positive relationships of FA with the number of lifetime sexual partners and one-night stands emerged. Thus, in a large sample and using a more highly aggregated FA index, our study fails to replicate previous findings, though equivalence testing also did not support deviation from previous meta-analytic estimates, especially for men. No associations were found for MPAs and FA in atd angles in either sex.     

Multiple partners are associated with higher testosterone in North American men and women

Previous research has shown that being partnered is associated with lower testosterone (T) in men and women. To address how multiple partners may be associated with T, we examined 47 men and 48 women who were single, monoamorously partnered (partnered), polyamorous (having multiple committed relationships), or in a polyamorous lifestyle but not currently multipartnered. Men who were partnered had lower T than all other men, and polyamorous men had higher T than single men. Polyamorous women had higher T than all other women. Measures of sociosexual orientation (SOI) and sexual desire differed in women by relationship type, but not in men. Findings are interpreted in light of 'competitive' and 'bond-maintenance' relationship orientations and statuses.     

Mate choice trade-offs and women’s preference for physically attractive men

Researchers studying human sexuality have repeatedly concluded that men place more emphasis on the physical attractiveness of potential mates than women do, particularly in long-term sexual relationships. Evolutionary theorists have suggested that this is the case because male mate value (the total value of the characteristics that an individual possesses in terms of the potential contribution to his or her mate’s reproductive success) is better predicted by social status and economic resources, whereas women’s mate value hinges on signals conveyed by their physical appearance. This pattern may imply that women trade off attractiveness for resources in mate choice. Here I test whether a trade-off between resources and attractiveness seems to be occurring in the mate choice decisions of women in the United States. In addition, the possibility that the risk of mate desertion drives women to choose less attractive men as long-term mates is tested. The results were that women rated physically attractive men as more likely to cheat or desert a long-term relationship, whereas men did not consider attractive women to be more likely to cheat. However, women showed no aversion to the idea of forming long-term relationships with attractive men. Evidence for a trade-off between resources and attractiveness was found for women, who traded off attractiveness, but not other traits, for resources. The potential meaning of these findings, as well as how they relate to broader issues in the study of sex differences in the evolution of human mate choice for physical traits, is discussed.     

Same-Sex Gaze Attraction Influences Mate-Choice Copying in Humans

Mate-choice copying occurs when animals rely on the mating choices of others to inform their own mating decisions. The proximate mechanisms underlying mate-choice copying remain unknown. To address this question, we tracked the gaze of men and women as they viewed a series of photographs in which a potential mate was pictured beside an opposite-sex partner; the participants then indicated their willingness to engage in a long-term relationship with each potential mate. We found that both men and women expressed more interest in engaging in a relationship with a potential mate if that mate was paired with an attractive partner. Men and women''s attention to partners varied with partner attractiveness and this gaze attraction influenced their subsequent mate choices. These results highlight the prevalence of non-independent mate choice in humans and implicate social attention and reward circuitry in these decisions.     

How conception risk affects competition and cooperation with attractive women and men

We investigated competition and cooperation for resources across the menstrual cycle in the context of bargaining games. Although bargaining has been studied within an evolutionary framework, little attention has been paid specifically to the role of mating motives in economic behavior. To investigate how motives related to reproductive success affect bargaining, participants at high or low risk for conception or who were on oral contraceptives played ultimatum and dictator games with partners who varied in sex and facial attractiveness. In ultimatum games, women in the fertile phase were more competitive over resources with attractive women than with less attractive women. Intrasexual competition was not observed in dictator games. Women were more cooperative with attractive men than with less attractive men in both games, regardless of fertility status. Low fertility women were more cooperative with attractive members than with less attractive members of both sexes in both games. Results support the view that, during periods of high fertility, when women are most intrasexually competitive for mates, withholding resources from potential rivals would enable women to gain the means to enhance their attractiveness and weaken competitors' abilities to do the same at a time when relative advantages in appearance are most crucial to reproductive success. The lack of a fertility effect for cooperation with potential mates supports the view that displays of generosity accrue benefits for women across the cycle in their efforts to attract men who will invest in relationships.     

It's not just lunch: extra-pair commensality can trigger sexual jealousy

Do people believe that sharing food might involve sharing more than just food? To investigate this, participants were asked to rate how jealous they (Study 1)--or their best friend (Study 2)--would be if their current romantic partner were contacted by an ex-romantic partner and subsequently engaged in an array of food- and drink-based activities. We consistently find--across both men and women--that meals elicit more jealousy than face-to-face interactions that do not involve eating, such as having coffee. These findings suggest that people generally presume that sharing a meal enhances cooperation. In the context of romantic pairs, we find that participants are attuned to relationship risks that extra-pair commensality can present. For romantic partners left out of a meal, we find a common view that lunch, for example, is not "just lunch."     

Resources,attractiveness, family commitment; reproductive decisions in human mate choice

This study of reproductive decisions in human mate selection used data from "lonely hearts" advertisements to examine a series of predictions based on the mate preferences of male and females relating to age; physical appearance; financial condition and socioeconomic status; family commitment and personal traits; short- and long-term mating; and marital status and preexisting children. The sample consisted of 1000 personal advertisements (500 male) placed in two daily, national papers between February and October 1994 in Hungary. The research procedure included a pilot study of 150 advertisers (75 male) to refine the categories examined. Analysis was performed using 1) a matrix with one axis referring to offers and the other to demands of males and females separately; 2) a matrix of offers only to derive correlated traits of claims by males and females; and 3) a matrix with columns describing sex, offers, demands, advertiser's age, and required age and a row for each of the 1000 samples. It was found that men preferred younger mates, while women preferred older ones. Men were more likely to seek physical attractiveness, while women were more likely to seek financial resources (ranked 7th) and high status (ranked 6th). Women strongly preferred male domestic virtue and family commitment, and twice as many women as men demanded long-term relationships. Women more frequently declared preexisting children, and men exhibited a reluctance to accept these children. Both males and females employed "trade-off" strategies, making greater demands if they felt they had attractive offers.     

Mate Choice Copying in Humans

There is substantial evidence that in human mate choice, females directly select males based on male display of both physical and behavioral traits. In non-humans, there is additionally a growing literature on indirect mate choice, such as choice through observing and subsequently copying the mating preferences of conspecifics (mate choice copying). Given that humans are a social species with a high degree of sharing information, long-term pair bonds, and high parental care, it is likely that human females could avoid substantial costs associated with directly searching for information about potential males by mate choice copying. The present study was a test of whether women perceived men to be more attractive when men were presented with a female date or consort than when they were presented alone, and whether the physical attractiveness of the female consort affected women’s copying decisions. The results suggested that women’s mate choice decision rule is to copy only if a man’s female consort is physically attractive. Further analyses implied that copying may be a conditional female mating tactic aimed at solving the problem of informational constraints on assessing male suitability for long-term sexual relationships, and that lack of mate choice experience, measured as reported lifetime number of sex partners, is also an important determinant of copying.     

‘Beach-Boy Elders’ and ‘Young Big-Men’: Subverting the Temporalities of Ageing in Kenya's Ethno-Erotic Economies

ABSTRACT

In the 1980s, Samburu men from northern Kenya began migrating to coastal tourist resorts to sell souvenirs and perform traditional dances for European tourists. Many of them engaged in transactional sex or marriages with European women attracted to the image of the exotic African young male warrior. Through relationships with European women, some Samburu men managed to rapidly accumulate wealth, becoming so-called ‘young big-men’. As a way to transform their wealth into more durable forms of respectability, these men used their money to marry local women and speed up their ritual initiation into elderhood. Meanwhile, there also emerged the figure of ‘beach-boy elders’, men who aged before accumulating sufficient wealth. They returned to coastal tourist resorts, dressed as young warriors, and waited to find European partners. In the article, I argue that beach-boy elders and young big-men produce queer moments in the temporalities of ageing, in that they subvert normative expectations of ageing at the very same time that they seek to produce them.     

Know Thy Neighbor: Costly Information Can Hurt Cooperation in Dynamic Networks

People need to rely on cooperation with other individuals in many aspects of everyday life, such as teamwork and economic exchange in anonymous markets. We study whether and how the ability to make or break links in social networks fosters cooperate, paying particular attention to whether information on an individual''s actions is freely available to potential partners. Studying the role of information is relevant as information on other people''s actions is often not available for free: a recruiting firm may need to call a job candidate''s references, a bank may need to find out about the credit history of a new client, etc. We find that people cooperate almost fully when information on their actions is freely available to their potential partners. Cooperation is less likely, however, if people have to pay about half of what they gain from cooperating with a cooperator. Cooperation declines even further if people have to pay a cost that is almost equivalent to the gain from cooperating with a cooperator. Thus, costly information on potential neighbors'' actions can undermine the incentive to cooperate in fluid networks.     

Changing racial boundaries and mixed unions: the case of second-generation Filipino Americans

I examine an understudied topic of intermarriage – nonwhite mixed unions. Drawing on a study of second-generation Filipino Americans, I compare how respondents in inter-ethnic (those partnered with other Asians) and nonwhite interracial (i.e. Latino, black, and non-Asian bi-racial) unions perceive racial boundaries, or their ‘racial schemas’. I argue that mixed unions can change how partners view racial boundaries. Drawing on phenotype, culture, and power position, both inter-ethnically and nonwhite interracially partnered respondents viewed themselves as different from whites. However, they differed in how they constructed nonwhite boundaries. Respondents in inter-ethnic unions drew on their Asian identity to distinguish themselves from Latinos and blacks, while informants in nonwhite interracial unions highlighted their Filipino identity to distance themselves from East Asians and align themselves with Latinos and blacks. These findings show that marriage affects racial boundary development and that mixed unions impact individuals’ racial incorporation.