Amounts Spent on Engagement Rings Reflect Aspects of Male and Female Mate Quality

Previous research has shown that the qualities of nuptial gifts among nonhumans and marriage-related property transfers in human societies such as bridewealth and dowry covary with aspects of mate quality. This article explores this issue for another type of marriage-related property transfer: engagement rings. We obtained data on engagement ring costs and other variables through a mail survey sent to recently married individuals living in the American Midwest. This article focuses on survey responses regarding rings that were purchased by men acting alone and using only their own funds who then presented the rings while making surprise proposals of marriage (n = 127). Men marrying younger women spent more on rings, as did men who earned more money and whose fiancées earned more money. These findings suggest that the amounts spent on engagement rings, like bridewealth and dowry payments in other societies, reflect aspects of both male and female mate quality.     

Demographic Dimensions of an Intervillage Land Dispute in Nubri, Nepal

The demographic basis for a land dispute between two Tibetan villages in Nubri, Nepal, is examined in relation to family systems. Despite close proximity and sociocultural ties, the villages experience divergent population growth rates resulting from different frequencies of marriage. In one, old-age security concerns induce parents to retain female labor within the household by designating daughters to be nuns, a practice that has the unintended consequence of limiting aggregate population growth by barring many women from marriage and reproduction. In the other village the slightly different family system results in fewer nuns, faster population growth, and a need for more land. Comparisons with family systems and demographic outcomes in Europe and Asia reveal this to be a case in which preventive checks can exist in a context of early marriage and high marital fertility and demonstrate how concerns for old-age security can act as a restraint on aggregate fertility. [ Tibetans, family systems, demography, religious celibacy ]     

Love by arrangement: the ambiguity of 'spousal choice' in a Turkish village

Through an ethnographic story of a couple in a village in western Turkey who met by arrangement and created a romance before marriage, I explore the relationship between courtship and ideologies of modernity. Parents have absorbed the prejudice that arranged marriage is outmoded and claim they refuse to arrange marriages as a sign of enlightened modernity. In contrast to ideological claims, arranged marriage is not uncommon. Today, arranged marriage bridges the apparent gap between love-match and arrangement, as parents allow children space for developing romance after engagement. This article shows how ideologies of modernity are modified to accommodate individual needs, and in the process parents are willing to expand the definition of arranged marriage to include romance.     

Intermarriage and reciprocal household exchange practices in a mixed community in Roti,Indonesia

For several generations, intermarriage has been common between indigenous Rotinese Christians and migrant Muslims and their descendants in the Indonesian village of Oelua on Roti Island. Muslims have engaged with the customary institutions upheld by indigenous Rotinese Christians—namely, those associated with marriage proposals and bridewealth. They have also engaged in reciprocal inter‐household exchanges to raise the cash to pay for weddings and bridewealth, as well as for other life cycle events such as funeral feasts and gatherings in the post‐funeral mourning period. This article argues that intermarriage and inter‐household monetary exchanges are important, among other factors, in promoting low conflict relations between the two groups, primarily because of the regular opportunities generated to interact in both public and private spheres. Marriage preferences in Oelua are changing, however, with young Muslim men preferring to marry women who subscribe to the same religion and similar customs. Muslim attitudes are also changing with respect to their involvement in inter‐household reciprocal exchanges, with many wanting to engage in different ways, or not at all. The article discusses what these changing attitudes and practices may mean for maintaining congenial inter‐group relations between Christians and Muslims in the future.     

High incidence of profound deafness in an isolated community

In a Muslim Israeli Arab village, different types of hearing loss affect some 2% of the inhabitants. Most cases of profound deafness are due to recessive mutations in the Connexin-26 gene. Since in this community, marriages are by preference within the family (consanguineous), for many of the couples from the village the risk for an affected child is high. There are 30 families living in the village in which both parents have normal hearing and at least one child has a profound hearing defect. In these families, the birth of a child with profound deafness did not change family planning. The rate of marriage was similar for the siblings of deaf children as for other individuals in the village. The major problems were encountered by the deaf individuals themselves; in particular, most of the women were not married. Because of the distinctive nature of this particular problem, different types of screening programs were envisaged. However, all of them are problematic. Therefore, as a first step it was decided to begin a program including individual genetic counseling together with education of the entire population on practical aspects of human genetics.     

From bridewealth to dowry?

Significant amounts of wealth have been exchanged as part of marriage settlements throughout history. Although various models have been proposed for interpreting these practices, their development over time has not been investigated systematically. In this paper we use a Bayesian MCMC phylogenetic comparative approach to reconstruct the evolution of two forms of wealth transfers at marriage, dowry and bridewealth, for 51 Indo-European cultural groups. Results indicate that dowry is more likely to have been the ancestral practice, and that a minimum of four changes to bridewealth is necessary to explain the observed distribution of the two states across the cultural groups. A preliminary version of this paper was presented at the 16^th meeting of the Human Behavior and Evolution Society (HBES), Berlin 2004. Mark Pagel and Andrew Meade provided the software, the coded linguistic data, and valuable advice on their use. LF is funded by Fondazione Ing. Aldo Gini (Italy), the ESRC (UK), and the UCL Graduate School (UK). Five anonymous reviewers provided helpful comments. The authors are based at the Department of Anthropology of UCL and members of the AHRC Centre for the Evolutionary Analysis of Cultural Behaviour (CEACB). LF is studying towards a PhD, CH is a CEACB Senior Research Fellow, and RM is Professor of Evolutionary Anthropology.     

Natal dispersal and parental escorting predict relatedness between mates in a passerine bird

Although relatedness between mates is of considerable evolutionary and ecological significance, the way in which the level of relatedness is determined by different behavioural processes remains largely unknown. We investigated the role of behaviour in predicting mate relatedness in great tits using genotypic markers and detailed observations. We studied how mate relatedness is influenced by natal dispersal, inbreeding/outbreeding avoidance after natal dispersal and a behaviour not previously considered that influences membership to social aggregations, namely family escorting behaviour by parents. Among locally born individuals, the level of mate relatedness decreased with natal dispersal distance for females, but not for males. In contrast, mate relatedness was negatively related to the extent of family movements for males, but not for females. However, family movements did not predict dispersal distance for either sex. Local recruits were more related to their mates than immigrants, but this was only significant for females. No evidence was found for inbreeding/outbreeding avoidance after dispersal. Our results suggest that, in highly mobile species, mating options are spatially and/or socially limited, and that parents influence mating options of their offspring before dispersal.     

Female mate choice and male–male competition in Tonkean macaques: Who decides?

The theory of sexual selection predicts that females should be discriminatory in the choice of sexual partners. Females can express their choice in two ways. In direct mate choice, they show preferences for certain partners. In indirect mate choice, they select partners by displaying sexually attractive traits, thus eliciting contest competition between males. We focused on a primate species in which females advertise the timing of their ovulation and studied the balance between these two choice strategies. We tested predictions related to three hypotheses about direct and indirect female choice, namely the best‐male, graded‐signal and weak‐selectivity hypotheses. We investigated the sexual and agonistic interactions occurring during oestrous periods in five captive groups of Tonkean macaques (Macaca tonkeana). The results showed that dominant males used mate guarding to monopolise sexual access to parous females that were in the fertile stage of their reproductive cycle, while lower‐ranking males monitored only nulliparous females. The distribution of sexual presentations indicated that females accepted different types of partners, supporting the weak‐selectivity hypothesis regarding direct mate choice. The analysis of behavioural sequences revealed that mate‐guarding males used mild coercive behaviours to prevent females from mating with other males at conception time. The distribution of mounts showed that females mainly mated with dominant males, which leads us to argue that the best‐male hypothesis provides the most parsimonious explanation regarding indirect mate choice in Tonkean macaques. At the individual level, it may be concluded that male competitive strategies prevented females from exercising direct mate choice. At the evolutionary level, however, female sexual advertising and thus indirect choice promoted competition between males. The outcome is that indirect mate choice appears more important than direct mate choice in female Tonkean macaques.     

Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating

Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents ([Formula: see text] individuals) to test for genetic and family environmental influences on mate choice, while controlling for and not controlling for the effects of assortative mating. Key traits were analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females' mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernible pattern of mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also at least in part to phenotypic matching.     

Women’s strategies in polygynous marriage

Both behavioral ecological and social anthropological analyses of polygynous marriage tend to emphasize the importance of competition among men in acquisition of mates, whereas the strategic options to women both prior to and after the establishment of a marriage have been neglected. Focusing on African marriage systems that are in some senses analogous to resource-defense polygyny, I first review the evidence of reproductive costs of polygyny to women. Then I discuss why the conflict of interests between men and women over mate number is often likely to be settled in favor of men. Using East African ethnographic data I examine the strategic responses of women and their families to polygynous marriage, focusing on four topics: mate choice (Kipsigis), attitudes toward incoming wives (Kipsigis), labor allocation and cooperation (comparative data, Kipsigis), and use of parental wealth (Datoga). The results of these quantitative analyses suggest that through a combination of judicious marriage choice and strategic responses within marriage, polygyny need not be costly to women in resource-defense polygynous systems. The conclusion is that a hierarchy of questions need to be addressed in the analysis of any polygynous marriage system.     

How Consistently are Good Parents Good Parents? Repeatability of Parental Care in the House Sparrow,Passer domesticus

In many avian species, substantial individual variation occurs in parental food‐provisioning levels, which often is assumed to reflect variation in parental quality. Parental quality also has often been invoked as a key element in mate choice among biparental species, and many sexually‐selected traits have been investigated as potential predictors of parental quality. In recent studies of house sparrow (Passer domesticus) parents, we found that individuals behaved remarkably consistently across time, regardless of temporary manipulations of the nestling provisioning of their partners. This suggests that variation in parental competence may be attributable to quality differences among individuals. One prediction of the ‘parental quality differences’ hypothesis is that individuals also should show consistency in their provisioning behavior across broods. To test this, we compared the parental delivery rates of individual house sparrows across broods. Parents of both sexes reduced their per‐chick delivery rates as the season progressed; parents of both sexes were also responsive to changes in their brood sizes. Despite these sources of environmental variation in provisioning rates, the parental care of individual males was highly repeatable across broods. By contrast, female parental care showed extremely low repeatability, and standardized measures of among‐individual variation in parental behavior revealed females to be much less variable than males. These results indicate that females in this multi‐brooded species have much to gain from mate‐choice decisions predicated on male parental quality or accurate indicators of such, whereas males are less likely to profit from being highly selective about the ‘parental quality’ of their partners.     

The evolution of parent–offspring conflict over mate choice

In human societies, parents often have a strong influence on the mate choice of their offspring. Moreover, empirical studies show that conflict over mate choice between parents and offspring is widespread across human cultures. Here we provide the first theoretical investigation into this conflict, showing that it may result from an underlying evolutionary conflict over parental resource distribution. We present a series of evolutionary simulations in which we gradually expand a standard model of sexual selection by the stepwise addition of elements of parental involvement. In our model, females obtain resources enhancing their fecundity from both their chosen mate and their parents. Potential mates differ in their ability to provide resources and may signal this ability. Both females and their parents can develop a preference for the signal, with both preferences influencing the realized mate choice of the female. Parents may differentially allocate resources among their daughters depending on the resource-provisioning abilities of their sons-in-law. When fecundity returns on investment are diminishing, we find that parents invest most in daughters whose mates provide few resources. Subsequently, the daughters evolve to exploit this allocation rule through their mate choice, which is not in the parents' best interests. This results in a conflict over mate choice between parents and their offspring, manifested as an on-going divergence of offspring and parental preferences. We predict that the conflict should be most pronounced when fathers, as opposed to mothers, control resource allocation.     

Mate choice in a changing world

Human activities by altering environmental conditions are influencing the mate choice of animals. This is by impacts on: (i) the production and expression of traits evaluated by mate choosers; (ii) the transmission of information about potential mates to choosers; (iii) the reception and processing of the information by choosers; and (iv) the final mate choice. Here, I first discuss how these four stages of the mate‐choice process can be altered by environmental change, and how these alterations, in turn, can influence individuals, populations, and communities. Much evidence exists for human‐induced environmental changes influencing mate choice, but the consequences for the fitness of courters and choosers are less well known, and even less is known about the impact on population dynamics, species interactions and community composition. More evidence exists for altered mate‐choice systems influencing interspecific matings and thereby community composition and biodiversity. I then consider whether plastic adjustments and evolutionary changes can rescue adaptive mate‐choice systems, and reflect on the possibility of non‐adaptive mate‐choice systems becoming less maladaptive under environmental change. Much evidence exists for plastic adjustments of mate‐choice systems, but whether these are adaptive is seldom known, as is the contribution of genetic changes. Finally, I contemplate the possibility of mate‐choice systems rescuing populations from decline in changing environments. I explain how this is context dependent with both positive and negative outcomes possible. In summary, while much evidence exists for human‐induced environmental changes influencing mate‐choice systems, less is known about the consequences for ecological and evolutionary processes. Considering the importance that mate choice plays in determining individual fitness and population viability, the effects of environmental change on mate‐choice systems should be considered in studies on the ecological and evolutionary consequences of human disturbances to habitats.     

Mate choice in the monogamous and polychromatic Midas cichlid, Cichlasoma citrinellum

Choice of mate in the Midas cichlid, Cichlasoma citrinellum (Günther, 1864), has been examined from a number of perspectives, proceeding from general species attributes to individual differences.
The Midas cichlid discriminates against closely-related, highly-similar Cichlasoma , and recognizes sex, probably chemically in both cases. It is polychromatic and changes from the normal (N) pattern to gold (G) or even white at almost any age. Gold colouration inhibited attack and made it difficult to mate an N female with a G male; the inhibiting effect was cancelled by using a larger N female.
Because the Midas cichlid is also biparentally monogamous, early experience could easily influence later choice of mate. G females of G × G parents preferentially spawned adjacent to G males; N females of N × N spawned mainly before N males. N females of G × G pairs, however, showed no preference.
Groups of females were reared by all four combinations of two colours and two sexes, or by no parents. Females reared by identically pure-coloured parents responded most to males of those colours, whereas females raised by mixed-colour parents did not discriminate. Females reared without parents preferred N males. Regardless of their own or their parents' colour, juveniles spent more time with N juveniles and behaved less aggressively towards them, compared to G juveniles.
Fish were offered a choice among potential mates that differed in aggressiveness, size or breeding experience. Males did not choose on the basis of those traits. Females preferred large, aggressive, experienced males. Pairs with large aggressive males more readily kept a breeding territory, and aggressive experienced males guarded young more effectively. All females were equally aggressive in protecting their young.     

A conceptual review of mate choice: stochastic demography,within‐sex phenotypic plasticity,and individual flexibility

Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell 2009 ). We found >3000 studies; 198 were empirical studies of within‐sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that “choosiness” of potential mates is environmentally and socially labile, that is, induced – not fixed – in “the choosy sex” with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity‐associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within‐sex plasticity in the choosy sex to between‐ and within‐individual flexibility in reproductive decision‐making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision‐making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within‐individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points.     

Sexual selection under parental choice: a revision to the model

Across human cultures, parents exercise considerable influence over their children’s mate choices. The model of parental choice provides a good account of these patterns, but its prediction that male parents exercise more control than female ones is not well founded in evolutionary theory. To address this shortcoming, the present article proposes a revision to the model. In particular, parental uncertainty, residual reproductive value, reproductive variance, asymmetry in the control of resources, physical strength, and access to weaponry make control over mating more profitable for male parents than female ones; in turn, this produces an asymmetrical incentive for controlling mate choice. Several implications of this formulation are also explored.     

Marriage: an evolutionary perspective

Marriage is universal, and pair bonding is found in other species too with highly dependent young. So marriage functions as a reproductive social arrangement that traditionally involved the extended family. The sexes are not identical in their biological contributions to children's survival, so they seek somewhat different attributes in a mate. Men seek a young, attractive, sexually faithful bride. Women seek a man who is older, taller, and (as in many other species) socially dominant. Both sexes prefer a kind, healthy, attractive, similar mate who is emotionally attached to them. A spouse who fails to maintain sufficiently high mate value is vulnerable to divorce. Infertility and sexual dissatisfaction predict divorce, as does death of a child, but the more children, the stabler the marriage. Cross-cultural data suggest that cruel or subdominant men (e.g., poor providers) and unfaithful women are prone to divorce. Marriages in which the wife dominates the husband in economic contributions, nonverbal behavior, and decision making tend to be less satisfying. In societies in which wives are economically independent of husbands, divorce rates are high. As women's economic power has risen with industrialization, divorce rates have climbed. Economic and fitness considerations also help explain cultural differences in polygyny, age at marriage, arranged marriage, concern with the bride's sexual chastity, and marriage ceremonies. Other factors also affect marital dynamics, such as state subsidies to families, the sex ratio, and influence of the couple's parents.     

Virus-immune dynamics determined by prey-predator interaction network and epistasis in viral fitness landscape

The emergence and persistence of polymorphism within populations generally requires specific regimes of natural or sexual selection. Here, we develop a unified theoretical framework to explore how polymorphism at targeted loci can be generated and maintained by either disassortative mating choice or balancing selection due to, for example, heterozygote advantage. To this aim, we model the dynamics of alleles at a single locus A in a population of haploid individuals, where reproductive success depends on the combination of alleles carried by the parents at locus A. Our theoretical study of the model confirms that the conditions for the persistence of a given level of allelic polymorphism depend on the relative reproductive advantages among pairs of individuals. Interestingly, equilibria with unbalanced allelic frequencies were shown to emerge from successive introduction of mutants. We then investigate the role of the function linking allelic divergence to reproductive advantage on the evolutionary fate of alleles within the population. Our results highlight the significance of the shape of this function for both the number of alleles maintained and their level of genetic divergence. Large number of alleles are maintained with substantial replacement of alleles, when disassortative advantage slowly increases with allelic differentiation . In contrast, few highly differentiated alleles are predicted to be maintained when genetic differentiation has a strong effect on disassortative advantage. These opposite effects predicted by our model explain how disassortative mate choice may lead to various levels of allelic differentiation and polymorphism, and shed light on the effect of mate preferences on the persistence of balanced and unbalanced polymorphism in natural population.

     

Covariation and repeatability of male mating effort and mating preferences in a promiscuous fish

Although mate choice by males does occur in nature, our understanding of its importance in driving evolutionary change remains limited compared with that for female mate choice. Recent theoretical models have shown that the evolution of male mate choice is more likely when individual variation in male mating effort and mating preferences exist and positively covary within populations. However, relatively little is known about the nature of such variation and its maintenance within natural populations. Here, using the Trinidadian guppy (Poecilia reticulata) as a model study system, we report that mating effort and mating preferences in males, based on female body length (a strong correlate of fecundity), positively covary and are significantly variable among subjects. Individual males are thus consistent, but not unanimous, in their mate choice. Both individual mating effort (including courtship effort) and mating preference were significantly repeatable. These novel findings support the assumptions and predictions of recent evolutionary models of male mate choice, and are consistent with the presence of additive genetic variation for male mate choice based on female size in our study population and thus with the opportunity for selection and further evolution of large female body size through male mate choice.     

Parental Control over Mate Choice to Prevent Marriages with Out-group Members

The present research examined how a preference for influencing the mate choice of one's offspring is associated with opposition to out-group mating among parents from three ethnic groups in the Mexican state of Oaxaca: mestizos (people of mixed descent, n?=?103), indigenous Mixtecs (n?=?65), and blacks (n?=?35). Nearly all of the men in this study were farmworkers or fishermen. Overall, the level of preferred parental influence on mate choice was higher than in Western populations, but lower than in Asian populations. Only among the Mixtecs were fathers more in favor of parental influence on the mate choice of children than mothers were. As predicted, opposition to out-group mating was an important predictor of preferred parental influence on mate choice, more so among fathers than among mothers, especially in the mestizo group-the group with the highest status. In addition, women, and especially mestizo women, expressed more opposition to out-group mating than men did.