Spousal correlation in risk attitude is estimated using data from the German Socio-Economic Panel over the period 2004–2009. We apply the bivariate panel ordered probit model to the analysis of the simultaneous determination of the male’s and the female’s risk attitude, using the survey question about general willingness to take risk, provided on a 0–10 Likert-scale. The correlations between both the individual-specific effects of the two partners and the two within-individual errors are separately estimated, and found to be +0.285 and (...) +0.310, respectively. We consider the former to be a key parameter, since its positive sign may be interpreted in terms of positive assortative mating on risk attitude: individuals tend to form partnerships with others having a similar risk attitude. We also find evidence that this correlation increases with years of marriage, suggesting either a form of spousal socialization or a selection process in which marriage breakdown is more likely in poorly matched couples. (shrink)

Height preferences reflecting positive assortative mating for height—wherein an individual’s own height positively predicts the preferred height of their mate—have been observed in several distinct human populations and are thought to increase reproductive fitness. However, the extent to which assortative preferences for height differ strategically for short-term versus long-term relationship partners, as they do for numerous other indices of mate quality, remains unclear. We explore this possibility in a large representative sample of over 500 men and women (...) aged 15–77 from Canada, Cuba, Norway and the United States. Participants’ own heights were measured, and they indicated their height preferences for a long-term and short-term mate using graphic stimuli containing metric indices. Replicating the “male-taller norm,” participants on average preferred taller-than-average male mates, and shorter-than-average female mates. Positive assortative preferences for height were observed across sexes and samples, however the strength of these height preferences varied with relationship context for men, and not for women. Taller men preferred relatively shorter women for short-term relationships than for long-term relationships, indicating stronger assortative preferences for height in a long-term context. These results provide preliminary evidence that, in addition to mate preferences for other physical traits related to mate quality such as masculinity in the body, face, and voice, assortative preferences for height do vary as a function of expected relationship length, but this was surprisingly only observed in preferences for female height. (shrink)

Using computer simulations I studied the simultaneous effect of variable environments, mutation rates, ploidy, number of loci subject to evolution and random and assortative mating on various reproductive systems. The simulations showed that mutants for sex and recombination are evolutionarily stable, displacing alleles for monosexuality in diploid populations mating assortatively under variable selection pressure. Assortative mating reduced excessive allelic variance induced by recombination and sex, especially among diploids. Results suggest a novel adaptive value for sex (...) and recombination. They show that the adaptive value of diploidy and that of the segregation of sexes is different to that of sex and recombination. The results suggest that the emergence of sex had to be preceded by the emergence of diploid monosexual organisms and provide an explanation for the emergence and maintenance of sex among diploids and for the scarcity of sex among haploid organisms. (shrink)

Uchiyama et al. productively discuss how culture can influence genetic heritability and, by modifying environmental conditions, limit the generalizability of genome-wide association studies (GWASs). Here, we supplement their account by highlighting how recent changes in culture and institutions in industrialized, westernized societies – such as increased female workforce participation – may have increased assortative mating. This alters the distribution of genotypes themselves, increasing heritability and phenotypic variance, and may be detectable using the latest methods.

Advances in multiagent simulation techniques make it possible to study more realistic dynamics of complex systems and allow evolutionary theories to be tested. Here I use simulations to assess the relative importance of reproductive systems (haplodiploidy vs. diploidy), mate selection (assortative mating vs. random mating) and social economics (pay-off matrices of evolutionary games) in the evolutionary dynamics leading to the emergence of social cooperation in the provision of parental care. The simulations confirm that haplo-diploid organisms and organisms (...) mating assortatively have a higher probability for fixing alleles and require less favorable conditions for their fixation, than diploids or organisms mating randomly. The simulations showed that social behavior was most likely to emerge a) when the cost for parental investment was much lower than the benefits to the offspring, b) when cooperation improved synergistically the fitness of offspring compared to the corresponding egoistic behavior and c) when alleles coding for altruistic or social behavior could be rapidly fixed in the population, thanks to mechanisms such as haplo-diploidy and/or assortative mating. Cooperative social behavior always appeared if sociality conferred much higher fitness gains compared to non cooperative alternatives suggesting that the most important factors for the emergence and maintenance of social behavior are those based on energetic or efficiency considerations. The simulations, in congruence with the scant experimental evidence available, suggest that economic considerations rather than genetic ones are critical in explaining the emergence and maintenance of sociality. (shrink)

A secondary analysis was performed on preliminary data from an ongoing cross-cultural study on assortative pairing. Independently sampled pairs of opposite-sex romantic partners and of same-sex friends rated themselves and each other on Life History (LH) strategy and mate value. Data were collected in local bars, clubs, coffeehouses, and other public places from three different cultures: Tucson, Arizona; Hermosillo, Sonora; and San José, Costa Rica. The present analysis found that slow LH individuals assortatively pair with both sexual and social (...) partners more strongly than fast LH individuals. We interpret this phenomenon as representing (1) an adaptation for preserving coadapted genomes in slow LH strategists to maintain high copying fidelity genetic replication while producing a lower number of offspring in stable, predictable, and controllable environments and (2) a bet-hedging adaptation in fast LH strategists, favoring the genetic diversification of a higher number of offspring in unstable, unpredictable, and uncontrollable environments. (shrink)

Contemporary mate preferences can provide important clues to human reproductive history. Little is known about which characteristics people value in potential mates. Five predictions were made about sex differences in human mate preferences based on evolutionary conceptions of parental investment, sexual selection, human reproductive capacity, and sexual asymmetries regarding certainty of paternity versus maternity. The predictions centered on how each sex valued earning capacity, ambition— industriousness, youth, physical attractiveness, and chastity. Predictions were tested in data from 37 samples drawn from (...) 33 countries located on six continents and five islands. For 27 countries, demographic data on actual age at marriage provided a validity check on questionnaire data. Females were found to value cues toresource acquisitionin potential mates more highly than males. Characteristics signalingreproductive capacitywere valued more by males than by females. These sex differences may reflect different evolutionary selection pressures on human males and females; they provide powerful cross-cultural evidence of current sex differences in reproductive strategies. Discussion focuses on proximate mechanisms underlying mate preferences, consequences for human intrasexual competition, and the limitations of this study. (shrink)

This study aims to investigate assortative mating based on mate value from male perspective. Male participants (132 Brazilian and 106 American) evaluated hypothetical “stimulus” males described in terms of physical attractiveness, social skills, and social status (each varied in high or low levels). Participants rated each stimulus and each stimulus' preferred mating partner on nine traits. The results showed that (1) positive assortative mating was expected in romantic relationships; (2) the stimulus ratings did not vary (...) independently, suggesting that mate value is the result of the interaction of the characteristics of individuals; and (3) that participants expected physically attractive and healthier female partners to pair with high-status male stimuli. The American and Brazilian mating expectations were similar, minor differences indicate that Brazilian participants considered men with high levels of social skills to be more ambitious and intelligent; American participants expected men of high status to be healthier; Brazilians expect men of high status to have more attractive faces, while Americans expected these men to possess more attractive bodies; and Brazilian participants assigned more attractive bodies to men of lower status. These differences reflect the influence of economic and cultural factors on the local environment. The study contributes to the understanding of the construction of market value and reveals that male expectations are in line with human mating preferences. The investigation of mating expectations can be a rich approach to investigate socio-cultural aspects that are related to mating in different cultures. (shrink)

Results of an agent-based computer simulation of the evolution of diploid sexual organisms showed that several mate selection strategies confer much higher average fitness to the simulated populations, and higher evolutionary stability to the alleles coding for these strategies, than random mating. Strategies which select for ''good genes'' were very successful, and so were strategies based on assortative mating. The results support the hypothesis that mating is not likely to be random in nature and that the (...) most successful mate selection strategies are those based on assortative mating or on advantageous genes. (shrink)

All organisms live in close association with microbes. However, not all such associations are meaningful in an evolutionary context. Current debate concerns whether hosts and microbes are best described as communities of individuals or as holobionts (selective units of hosts plus their microbes). Recent reports that assortative mating of hosts by diet can be mediated by commensal gut microbes have attracted interest as a potential route to host reproductive isolation (RI). Here, the authors discuss logical problems with this (...) line of argument. The authors briefly review how microbes can affect host mating preferences and evaluate recent findings from fruitflies. Endosymbionts can potentially influence host RI given stable and recurrent co‐association of hosts and microbes over evolutionary time. However, observations of co‐occurrence of microbes and hosts are ripe for misinterpretation and such associations will rarely represent a meaningful holobiont. A framework in which hosts and their microbes are independent evolutionary units provides the only satisfactory explanation for the observed range of effects and associations. (shrink)

Any biological species of biparental organisms necessarily includes, and is fundamentally dependent on, sign processes between individuals. In this case, the natural category of the species is based on family resemblances, which is why a species is not a natural kind. We describe the mechanism that generates the family resemblance. An individual recognition window and biparental reproduction almost suffice as conditions to produce species naturally. This is due to assortativity of mating which is not based on certain individual traits, (...) but on the difference between individuals. The biosemiotic model described here explains what holds a species together. It also implies that boundaries of a species are fundamentally fuzzy, and that character displacement occurs in case of sympatry. Speciation is a special case of discretisation that is an inevitable result of any communication system in work. The biosemiotic mechanism provides the conditions and communicative restrictions for the origin and persistence of diversity in the realm of living systems. (shrink)

No single theory so far proposed gives a wholly satisfactory account of the origin and maintenance of bird-song dialects. This failure is the consequence of a weak comparative literature that precludes careful comparisons among species or studies, and of the complexity of the issues involved. Complexity arises because dialects seem to bear upon a wide range of features in the life history of bird species. We give an account of the principal issues in bird-song dialects: evolution of vocal learning, experimental (...) findings on song ontogeny, dialect descriptions, female and male reactions to differences in dialect, and population genetics and dispersal.We present a synthetic theory of the origin and maintenance of song dialects, one that accommodates most of the different systems reported in the literature. The few data available suggest that large, regional dialect populations are genetically differentiated; this pattern is correlated with reduced dispersal between dialects, assortative mating by females, and male-male exclusion. At the same time, “subdialects” may be formed within regional dialects. Subdialect clusters are usually small and may represent vocal mimicry among a few adjacent territorial males. The relative importance of genetic and social adaptation may contribute to the emergence of subdialects; their distinctiveness may be correlated with the degree of polygyny, for example. Thus, subdialect formation is linked to one theory of the evolution of repertoire size, but data are too fragmentary to examine this idea critically. (shrink)

The 1000-year-old novel The Tale of Genji, written by Murasaki Shikibu around 1002 CE, shows the operation of general principles of sociobiology. Isolated from western influences and cloaked in Japanese traditions, the common traits associated with reproductive processes are clearly evident. The novel depicts the differential investment of males and females in offspring, male competitive behaviors, and concerns for paternity, kin selection, reciprocal social exchange, species-typical emotional expression, female mate choice, positive assortative mating, and acknowledgment of hereditary transmission (...) of physical and psychological traits. The nature of human behavior in Genji’s time seems little different than now and has all the attributes of species-specific and universal traits. Indeed, it can be argued that the fundamental characteristics of Homo sapiens have never changed, being influenced only in form by culture. The qualitative and quantitative evaluation of ancient texts is a strong methodology for understanding the invariant nature of human behavior. (shrink)

Human homogamy may be caused in part by individuals’ preference for phenotypic similarities. Two types of preference can result in homogamy: individuals may prefer someone who is similar to themselves (self-referent phenotype matching) or to their parents (a sexual-imprinting-like mechanism). In order to examine these possibilities, we compare faces of couples and their family members in two ways. First, “perceived” similarity between a pair of faces is quantified as similarity ratings given to the pair. Second, “physical” similarity between two groups (...) of faces is evaluated on the basis of correlations in principal component scores generated from facial measurements. Our results demonstrate a tendency to homogamy in facial characteristics and suggest that the tendency is due primarily to self-referent phenotype matching. Nevertheless, the presence of a sexual-imprinting-like effect is also partially indicated: whether individuals are involved in facial homogamy may be affected by their relationship with their parents during childhood. (shrink)

Species evolve, very slowly, through selection of genes which give rise to phenotypes well adapted to their environments. The cultures, including the languages, of human communities evolve, much faster, maintaining at least a minimum level of adaptedness to the external, non- cultural environment. In the phylogenetic evolution of species, the transmission of information across generations is via copying of molecules, and innovation is by mutation and sexual recombination. In cultural evolution, the transmission of information across generations is by learning, and (...) innovation is by sporadic invention or borrowing from other cultures. This much is the foundational bedrock of evolutionary theory. But things get more complicated; there can be gene-culture co-evolution. Prior to the rise of culture, the physical environment is the only force shaping biological evolution from outside the organism, and cultures themselves are clearly constrained by the evolved biological characteristics of their members. But cultures become part of the external environment, and influence the course of biological evolution. For example, altruistic cultures with developed medical knowledge reduce the cost to the individual of carrying genes disposing to certain pathologies (such as diabetes); and such genes become more widespread in the populations maintaining such cultures. Assortative mating can affect biological evolution, and particular cultures may influence the factors which are sorted for in mating. (For a careful discussion of the effects of cultural evolution on natural selection, see Cavalli-Sforza and Bodmer, 1971:774- 804). This paper examines mechanisms involved in the co-evolution of a biological trait, the critical period for language acquisition, and a property of human cultures, the size of their languages. A gene/culture interaction will be shown that can be described as a kind of symbiosis, but perhaps more aptly as an `arms race'. In this introduction, we will sketch the basic mechanics of the interaction in very broad terms; the rest of the paper will explain and justify the details. The implications of our model for second language acquisition are given toward the end of the paper. (shrink)

Measured inequality has increased tremendously between the 1960s and 1990s, not only in the United States but throughout the majority of industrial nations. Wages among people of the same race and gender have become less equal. The hours worked by men have fallen, and the drop has been more pronounced among those who earn lower wages—as a result, inequality in labor income, which is the product of the wage rate and hours worked, has increased relative to inequality in wage rates. (...) Moreover, among married couples, employment of the wives of high-income men has increased until these wives are approximately as likely to be employed outside the home as are the wives of low-income men, who have always worked for wages. In addition, due to assortative mating, wage rates of husbands and wives are positively correlated, and it is clear that the growth in inequality of labor incomes among families has outstripped the growth in inequality in individual labor income. Finally, only the highest-income families have savings in excess of home equity and company-sponsored pensions, which implies that inequality in wealth among families has been exacerbated by the growth in stock prices. (shrink)

MacDonald develops an evolutionary perspective on Judaism. Judaism is conceptualized as a group evolutionary strategy characterized by a high degree of endogamy and resistance to genetic and cultural assimilation. Data are provided to support the author's theory that Judaism is characterized by a high level of within-group altruism and competition with outgroups. Finally, MacDonald argues that Judaism has been characterized by eugenic practices aimed at high intelligence and high investment parenting. After outlining a theory of evolutionary group strategies, MacDonald discusses (...) the evidence from modern studies showing population genetic differences between Jews and Gentiles. He then shows that Jewish religious writing points to a pronounced tendency toward idealizing endogamy and condemning exogamy, and he points to the ways religious ideology and practice have facilitated the genetic and cultural separation of Jews and Gentiles. He then reviews evidence for resource and reproductive competition and the importance of kin-based cooperation and altruism as well as assortative mating for intelligence and resource aquisition ability among Jews. This study is a highly original attempt to develop an evolutionary understanding of one of the world's great religions. As such, it will be of concern to scholars and researchers in the fields of sociobiology and religion as well as the general reading public. (shrink)

Children may be viewed as public goods whereby both parents receive equal genetic benefits yet one parent often invests more heavily than the other. We introduce a microeconomic framework for understanding household investment decisions to address questions concerning conflicts of interest over types and amount of work effort among married men and women. Although gains and costs of marriage may not be spread equally among marriage partners, marriage is still a favorable, efficient outcome under a wide range of conditions. This (...) bioeconomic framework subsumes both cooperative and conflictive views on the sexual division of labor. We test hypotheses concerning marriage markets, assortative mating, and men’s labor motivations among Tsimane forager-horticulturalists of Bolivia and find that: (1) men and women both value work effort in marital partners, (2) marital labor contributions are complementary, (3) work effort is correlated between spouses, (4) total production is correlated with total reproduction, and (5) better hunters have higher fitness gains within marital unions. (shrink)

Speciation is the process by which one or more species arises from a common ancestor, and “macroevolution” refers to patterns and processes at and above the species level – or, transitions in higher taxa, such as new families, phyla or genera. “Macroevolution” is contrasted with “microevolution,” evolutionary change within populations, due to migration, assortative mating, selection, mutation and drift. In the evolutionary synthesis of the 1930’s and 40’s, Haldane , Dobzhansky , Mayr , and Simpson argued that the (...) origin of species and higher taxa were, given the right environmental conditions and sufficient time, the product of the same microevolutionary factors yielding change within populations. Dobzhansky reviewed the evidence from genetics, and argued, “nothing in the known macroevolutionary phenomena would require other than the known genetic principles for causal explanation” . In sum, genetic variation between species was not different in kind from the genetic variation within species. Dobzhansky concluded that one may “reluctantly put an equal sign” between micro- and macroevolution. In this chapter, I review arguments for and against this "neo-Darwinian" consensus on speciation, as well as debates concerning macroevolution and punctuated equilibrium. (shrink)

Augmenting and supplementing the arguments of Crespi & Badcock (C&B), I show that digit ratio (2D:4D), a putative marker of prenatal androgen action, indeed appears differentially altered in autism-spectrum disorders (lower/masculinized) versus schizophrenic-spectrum disorders (higher/feminized). Consistent with C&B's framework, some evidence (substantial heritability, assortative mating, sex-specific familial transmission) points to possible sex chromosome and imprinted genes effects on 2D:4D expression.

Partner preferences are expressed by many social species, including humans. They are commonly observed as selective contacts with an individual, more time spent together, and directed courtship behavior that leads to selective copulation. This review discusses the effect of conditioning on the development of heterosexual and homosexual partner preferences in rodents. Learned preferences may develop when a conditioned stimulus (CS) is associated in contingency with an unconditioned stimulus (UCS) that functions as a reinforcer. Consequently, an individual may display preference for (...) a partner that bears a CS. Some UCS may be more or less reinforcing, depending on when they are experienced, and may be different for males and females. For example, it could be that, only during periods of early development, that stimuli associated with nurture and juvenile play become conditioned. In adulthood, other stimuli such as sexual reward, cohabitation, mild stress, or even pharmacological manipulations may function as reinforcers to condition partner preferences. Evolutionary biologists and psychologists must take into consideration the idea that an individual’s experience with reward (i.e. sexual and pharmacological) can override presumably ‘innate’ mate choices (e.g. assortativeness and orientation) or mate strategies (e.g. monogamy or polygamy) by means of Pavlovian and operant contingencies. In fact, it is likely as innate to learn about the environment in ways that maximize reward and minimize aversive outcomes, making so-called ‘proximate’ causes (e.g. pleasure) ultimately more powerful predictors of social behavior and choice than so-called ‘ultimate’ causes (e.g. genetic or reproductive fitness). Keywords: pavlovian; operant; learning; sex; copulation (Published: 15 March 2012) Citation: Socioaffective Neuroscience & Psychology 2012, 2 : 17340 - DOI: 10.3402/snp.v2i0.17340. (shrink)

This article examines the implications of the transition to online or blended learning for first generation scholars (FGS) brought about by Covid-19. We present the findings of a mixed methods project that draws data from both in-depth qualitative interviews and a large quantitative survey of students at Durham University. We offer a comparative analysis of how FGS contrast to the general student body in relation to a range of key challenges that Covid-19 and the consequent ‘online pivot’ posed to university (...) life including technological, social and resource based issues. Our findings demonstrate that FGS were particularly affected by this shift to online or blended learning. The final substantive section discusses a range of potential mitigation strategies adopted by the School of Government and International Affairs, Durham University, with the assumption that some, at least, of these, and our data, will be of wider relevance in the sector. (shrink)

In Against the Musicologists (Math. 6), Sextus uses two types of arguments against musicology. Some would argue that a science of music – does not contribute to a happy life, while others deny that such a science has ever been established. Since the respective beliefs that musicology exists and that it benefits those who have mastered it are fine specimens of dogmatism, all Sextus has to do is to set the naysayers and the believers against each other in good Pyrrhonian (...) fashion. If their accounts balance each other out, he can go on to suggest that reasonable inquirers will suspend judgement as to the truth about these matters, while leaving everyday musical practice intact. Against the Musicologists thus lends itself to being read as an attempt to display the Sceptical capacity to motivate suspension of judgement in a specific domain where the Sceptic has detected dogmatic belief. -/- In what follows, I develop a reading of the treatise along these lines. In Section 5.1, I argue that Sextus’ polemical engagement with philosophical musicology sits well with the project of the treatise to which it belongs, and with a plausible understanding of his philosophical position as presented in the Outlines of Pyrrhonism (Pyr.). Then I turn to the two kinds of arguments that are contrasted by Sextus as being ‘more dogmatic’ and ‘more aporetic’ in spirit. After their brief presentation in Section 5.2, explaining the nature of their contrast by pointing to the diverging agendas that they originally served, I give an overview of both as ultimately aiming at epochē in Sections 5.3 and 5.4. Finally, in Section 5.5, I push back against readings that take the treatise to present a deviation from the suspensive outlook. (shrink)

In this paper, I argue that Emperor Julian’s use of the theory of common concepts is evidence for a general strategy of Platonist anti-Christian discourse: the attempt at showing that Christianity, as opposed to pagan philosophy, fails to live up to the commonly available standards of truth. After the introduction (§ 1), the paper offers a short summary of the Stoic theory of common concepts and their Platonist appropriation (§ 2). Then it turns to Julian’s account of the naturally arising (...) concept of god, offering an analysis of its Stoic and Platonist resonances (§3). Finally, I consider possible motivations for Julian’s formulation of anti-Christian polemics within this framework (§ 4). A few concluding paragraphs (§ 5) intend to situate this claim in Julian’s overall position and to point out its wider relevance for anti-Christian polemics. (shrink)

Review by: Maté Szabó The Bulletin of Symbolic Logic, Volume 19, Issue 1, Page 110-112, March 2013.

Reyes Mate's Memory of the West looks back in order to look forward. It is a sustained reflection on the great disillusion Europe experienced after World War I. Europeans understood that bombs had buried the Enlightenment. They knew that, to avoid catastrophe, they had to think anew. The catastrophe came, but Cohen, Benjamin, Kafka, and Rosenzweig had sounded the warning.