This article examines how sex differentiation is invoked from body fat with a focus on how various monitoring devices participate in the construction of bodies. By using the concept of ‘local biologies’, denoting the linkage of the body to place with its local physical and social conditions, it argues against the ‘one-size-fits-all’ paradigm of modern medicine and critiques the mechanistic search for regularity in medical research. By looking at medical literature on obesity and how contemporary obesity researchers and clinicians (...) link body fat to sex, local biologies of bodies in a Swedish obesity clinic are contrasted to the universal biologies represented in medical research. The article also provides empirical examples of how fat has the potential to undermine traditional sex and gender binaries. (shrink)

To reduce sex differences in employment outcomes, we must examine them in the context of the sex-gender hierarchy. The conventional explanation for wage gap—job segregation—is incorrect because it ignores men's incentive to preserve their advantages and their ability to do so by establishing the rules that distribute rewards. The primary method through which all dominant groups maintain their hegemony is by differentiating the subordinate group and defining it as inferior and hence meriting inferior treatment. My argument implies that neither sex-integrating (...) jobs nor implementing comparable worth will markedly improve women's employment status because men can subvert these mechanisms or even change the rules by which rewards are allocated. As evidence, I show that occupational integration has failed to advance women appreciably, and I argue that comparable worth is not likely to be much more effective. Instead, we must seek political analyses and political solutions. (shrink)

There are many obvious morphological and behavioural differences between male and female Drosophila, whose differing phenotypes are produced by a hierarchy of sex determination genes. These genes have been well characterised at the genetic and molecular level. Similarly, a number of sex‐specific differentiation genes have been characterised, such as the chorion and vitelline membrane genes in females and the sex peptide and other accessory gland proteins in males. Despite the depth of these parallel studies, there is only one example (...) of a direct link between the sex determination pathway and the downstream sex differentiation genes, namely the regulation of the female‐specific yolk protein genes. The yolk proteins are synthesised in the fat body and ovarian follicle cells of the adult female and are subsequently transported to the oocyte where they are stored for utilization during embrygenesis. The expression of the yolk protein genes is not entirely controlled by the sex determination hierarchy, as several different regulatory pathways must interact to direct their correct sexual, temporal and spatial regulation during development. (shrink)

Over the course of the 20th century the sex differential in life expectancy at birth in the industrialized countries has widened considerably in favour of women. Starting in the early 1970s, the beginning of a reversal in the long-term pattern of this differential has been noted in some high-income countries. This study documents a sustained pattern of narrowing of this measure into the later part of the 1990s for six of the populations that comprise the G7 countries: Canada, France, Germany, (...) Italy, England and Wales (as representative of the United Kingdom) and USA. For Japan, a persistence of widening sex differences in survival is noted. The sex differences in life expectancy are decomposed over roughly three decades (early 1970s to late 1990s) from the point of view of four major cause-of-death categories: circulatory diseases, cancers, accidents/violence/suicide, and (residual) causes. In the six countries where the sex gap has narrowed, this has resulted primarily from reduced sex differences in circulatory disease mortality, and secondarily from reduced differences in male and female death rates due to accidents, violence and suicide combined. In some of the countries sex differentials in cancer mortality have been converging lately, and this has also contributed to a narrowing of the difference in life expectancy. In Japan, males have been less successful in reducing their survival disadvantage in relation to Japanese women with regard to circulatory disease and cancer; and in the case of accidents/violence/suicide, male death rates increased during the 1990s. These trends explain the divergent pattern of the sex difference in life expectation in Japan as compared with the other G7 nations. (shrink)

Visual images are widely used in medical and patient education to enhance spoken or written explanations. This paper considers the role of such illustrations in shaping conceptions of the body; specifically, it addresses depictions of variant sexual anatomy and their part in the discursive production of intersex bodies. Visual language—even didactic, ‘factual’ visual language—carries latent as well as manifest content, and influences self-perceptions and social attitudes. In the case of illustrations about atypical sex development, where the need for non-stigmatising communication (...) is crucial, it is especially important to consider the implicit messages conveyed by imagery and compositional strategies. (shrink)

The same aggressive act will – all else being equal – have a different behavioral significance according to whether it is performed by a man or a woman. Such a perspective should have profound implications for legal and psychiatric practice, and for social policy in general.

Sex steroids, through their receptors, have potent effects on the signal pathways involved in osteogenic or myogenic differentiation. However, a considerable segment of those signal pathways has a prominent role in epithelial neoplastic transformation. The capability to intervene locally has focused on specific ligands for the receptors. Nevertheless, many signals are mapped to interactions of steroid receptor motifs with heterologous regulatory proteins. Some of those proteins interact with the glucocorticoid receptor and other factors essential to cell fate. Interactions of (...) steroid receptor domain motifs with heterologous proteins affect specific target pathways; consequently, manipulation of specified protein modules complexed with steroid receptors may be a next major step for enhancing molecular targeted therapeutics. In the future, intervention at specific sections of receptor primary sequence may prove therapeutically more efficient in targeting pathways of choice than ligand selectivity can be. (shrink)

We draw a distinction between defensive and predatory forms of aggression, and how these forms relate to basic neuropsychological systems, especially the Fight-Flight-Freeze-System (FFFS; putatively related to defensive aggression), and the Behavioural Approach System (BAS; putatively related to predatory aggression). These systems may help further to account for proximal brain processes and personality influences in the context of sex differences.

In the early 1980s, U.S. universities began regulating sexual relationships between professors and students. Such regulations are routinely justified by a rationale drawn from sexual-harassment law in the employment context: the power differential between professor and student precludes the possibility of genuine consent on the student’s part. This rationale is problematic, as feminists in the 1980s first observed, for its protectionist and infantilizing attitude toward (generally) women students. But it is also problematic in that it fails to register what is (...) truly ethically troubling about consensual professor-student sex. A professor’s having sex with his student constitutes a pedagogical failure: that is, a failure to satisfy the duties that arise from the practice of teaching. What is more, much consensual professor-student sex constitutes a patriarchal failure: such relationships often feed on, and reinforce, women’s second-class standing in higher education. As such, these relationships can thwart the legal right of women students, under Title IX, to exist in the university on equal terms with their male counterparts. Whether or not we should ultimately favor such an interpretation of Title IX—whether or not, that is, it would render campuses ultimately more equal for women and other marginalized people—it is clear that university professors need to attend more carefully to the sexual ethics of their own practice. (shrink)

Despite the importance of extrapair copulation (EPC) in human evolution, almost nothing is known about the design features of EPC detection mechanisms. We tested for sex differences in EPC inference-making mechanisms in a sample of 203 young couples. Men made more accurate inferences (φmen = 0.66, φwomen = 0.46), and the ratio of positive errors to negative errors was higher for men than for women (1.22 vs. 0.18). Since some may have been reluctant to admit EPC behavior, we modeled how (...) underreporting could have influenced these results. These analyses indicated that it would take highly sex-differentiated levels of underreporting by subjects with trusting partners for there to be no real sex difference. Further analyses indicated that men may be less willing to harbor unresolved suspicions about their partners’ EPC behavior, which may explain the sex difference in accuracy. Finally, we estimated that women underreported their own EPC behavior (10%) more than men (0%). (shrink)

Several hundred thousand intellectually talented 12-to 13-year-olds have been tested nationwide over the past 16 years with the mathematics and verbal sections of the Scholastic Aptitude Test (SAT). Although no sex differences in verbal ability have been found, there have been consistent sex differences favoring males in mathematical reasoning ability, as measured by the mathematics section of the SAT (SAT-M). These differences are most pronounced at the highest levels of mathematical reasoning, they are stable over time, and they are observed (...) in other countries as well. The sex difference in mathematical reasoning ability can predict subsequent sex differences in achievement in mathematics and science and is therefore of practical importance. To date a primarily environmental explanation for the difference in ability has not received support from the numerous studies conducted over many years by the staff of Study of Mathematically Precocious Youth (SMPY) and others. We have studied some of the classical environmental hypotheses: attitudes toward mathematics, perceived usefulness of mathematics, confidence, expectations/ encouragement from parents and others, sex-typing, and differential course-taking. In addition, several physiological correlates of extremely high mathematical reasoning ability have been identified (left-handedness, allergies, myopia, and perhaps bilateral representation of cognitive functions and prenatal hormonal exposure). It is therefore proposed that the sex difference in SAT-M scores among intellectually talented students, which may be related to greater male variability, results from both environmental and biological factors. (shrink)

Despite tremendous advances in neuroscience, the topic “brain, sex and gender” remains a matter of misleading interpretations, that go well beyond the bounds of science. In the 19th century, the difference in brain sizes was a major argument to explain the hierarchy between men and women, and was supposed to reflect innate differences in mental capacity. Nowadays, our understanding of the human brain has progressed dramatically with the demonstration of cerebral plasticity. The new brain imaging techniques have revealed the role (...) of the environment in continually re-shaping our brain all along our lifetimes as it goes through new experiences and acquires new knowledge. However, the idea that biology is a major determining factor for cognition and behavioral gender differentiation, is still very much alive. The media are far from being the only guilty party. Some scientific circles actively promote the idea of an innate origin of a gender difference in mental capacities. Experimental data from brain imaging, cognitive tests or genetics are often distorted to serve deterministic ideas. Such abuse of “scientific discourses” have to be counteracted by effective communication of clear and unbiased information to the citizens. This paper presents a critical analysis of selected examples which emphasize sex differences in three fields e.g. skills in language and mathematics, testosterone and financial risk-taking behavior, moral cognition. To shed light on the data and the methods used in some papers, we can now—with today’s knowledge on cerebral plasticity—challenge even more strongly, many false interpretations. Our goal here is double: we want to provide evidence against archaic beliefs about the biological determinism of sex differences but also promote a positive image of scientific research. (shrink)

In describing and explaining the sexes, medicine and science participated in the delineation of what was "feminine" and what was "masculine" in the Middle Ages. Hildegard of Bingen and Albertus Magnus, among others, writing about gynecology, the human constitution, fetal development, or the naturalistic dimensions of divine Creation, became increasingly interested in issues surrounding reproduction and sexuality. Did women as well as men produce procreative seed? How did the physiology of the sexes influence their healthy states and their susceptibility to (...) disease? Who derived more pleasure from sexual intercourse, men or women? The answers to such questions created a network of flexible concepts which did not endorse a single model of male-female relations, but did affect views on the health consequences of sexual abstinence for women and men and on the allocation of responsibility for infertility - problems with much social and religious significance in the Middle Ages. Sometimes at odds with, and sometimes in accord with other forces in medieval society, medicine and natural philosophy helped to construct a set of notions that divided significant portions of the world - from the behavior of animals to the operations of astrological signs - into "masculine" and "feminine." Even cases that seemed to exist outside the definitions of this duality, for example, hermaphrodite features or homosexual behavior, were brought under control by the application of gendered labels, such as "masculine women.". (shrink)

Sex selection and disability avoidance receive opposed treatment in bioethics literature, legislative practice and public opinion. However, some theorists question this state of affairs by drawing analogies between the harmful consequences of these practices. This paper shares their disapproval of gender selection and disability avoidance, but bases its resistance to these practices on an examination of the concepts of gender and disability. Here it identifies conceptual confusions as another cause of approval of sex selection and disability avoidance. Further, in clarifying (...) the nature of the concepts at issue, and their relationship with the subjects that they apply to, this discussion highlights the existence of relevant analogies between the concepts of gender and disability. Here the social construction and universality of gender and disability allow their differential treatment to be resisted at the conceptual level, creating a strong foundation for more consequentialist arguments against sex selection and disability avoidance. (shrink)

It is hypothesized from within an evolutionary framework that females should be less invested in peer relations than males. Investment was operationalized as enjoyment in Study 1 and as preference for interaction in Study 2. In the first study, four- and six-year-old children’s enjoyment of peer interaction was observed in 26 groups of same-sex peers. Girls were rated as enjoying their interactions significantly less than boys. In the second study, six- and nine-year-old children were interviewed about the individuals with whom (...) they spend time in their homes and neighborhoods and about the individuals who participate in their favorite activities. The proportion of individuals named by children who were peers was significantly lower for girls than boys both in children’s neighborhoods and in children’s favorite activities. Results strongly support the hypothesis that females and males have evolved differential preferences for interaction with peers. (shrink)

Schmitt's study provides strong support for sexual strategies theory (Buss & Schmitt 1993) – that men and women both have evolved a complex menu of mating strategies, selectively deployed depending on personal, social, and ecological contexts. It also simultaneously refutes social structural theories founded on the core premise that women and men are sexually monomorphic in their psychology of human mating. Further progress depends on identifying evolved psychological design features sensitive to the costs and benefits of pursuing each strategy from (...) the menu, which vary across mating milieus. These design features, like many well-documented mating adaptations, are likely to be highly sex-differentiated. (shrink)

This article considers 3 claims that cognitive sex differ- ences account for the differential representation of men and women in high-level careers in mathematics and sci- ence: (a) males are more focused on objects from the beginning of life and therefore are predisposed to better learning about mechanical systems; (b) males have a pro- file of spatial and numerical abilities producing greater aptitude for mathematics; and (c) males are more variable in their cognitive abilities and therefore predominate at the upper (...) reaches of mathematical talent. Research on cogni- tive development in human infants, preschool children, and students at all levels fails to support these claims. Instead, it provides evidence that mathematical and scientific rea- soning develop from a set of biologically based cognitive capacities that males and females share. These capacities lead men and women to develop equal talent for mathe- matics and science. (shrink)

Not all vertebrates share the familiar system of XX:XY sex determination seen in mammals. In the chicken and other birds, sex is determined by a ZZ:ZW sex chromosome system. Gonadal development in the chicken has provided insights into the molecular genetics of vertebrate sex determination and how it has evolved. Such comparative studies show that vertebrate sex‐determining pathways comprise both conserved and divergent elements. The chicken embryo resembles lower vertebrates in that estrogens play a central role in gonadal sex (...) class='Hi'>differentiation. However, several genes shown to be critical for mammalian sex determination are also expressed in the chicken, but their expression patterns differ, indicating functional plasticity. While the genetic trigger for sex determination in birds remains unknown, some promising candidate genes have recently emerged. The Z‐linked gene, DMRT1, supports the Z‐dosage model of avian sex determination. Two novel W‐linked genes, ASW and FET1, represent candidate female determinants. BioEssays 26:120–132, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

SummaryDuring famines females generally have a mortality advantage relative to males, and the highest levels of mortality occur in the very young and the elderly. One popular hypothesis is that the sex differential in mortality may reflect the greater body fatness combined with lower metabolism of females, which may also underpin the age-related patterns of mortality among adults. This study evaluated the ‘body fat’ hypothesis using a previously published and validated mathematical model of survival during total starvation. The model shows (...) that at a given body weight females would indeed be expected to survive considerably longer than males in the absence of food. At a mass of 70 kg for example a female aged 30 would survive for 144 days compared with life expectancy of only 95 days for a male of the same age and weight. This effect is contributed to by both the higher body fatness and lower metabolism of the females at a given body weight. However, females are generally smaller than males and in addition to a sex effect there was also a major effect of body size – heavier individuals survive longer. When this body size effect was removed by considering survival in relation to BMI the sex effect was much reduced, and could be offset by a relatively small difference in pre-famine BMI between the sexes. Nevertheless, combining these predictions with observed mean BMIs of males and females across 48 countries at the low end of the obesity spectrum suggests that in the complete absence of food females would survive on average about 40% longer than males. The energy balance model also predicted that older adult individuals should survive much longer than younger adult individuals, by virtue of their lower resting metabolic rates and lower activity levels. Observations of the female survival advantage in multiple famines span a much wider range than the model prediction. This suggests in some famines body fatness may be a significant factor influencing the mortality differential between the sexes, but in other famines other factors are likely to be more important. Moreover, the pattern of mortality in relation to age is completely opposite that predicted. These data emphasize the complex nature of famine mortality and suggest that a simple model of energy utilization alone is inadequate to explain the major aspects of this phenomenon. (shrink)

Recent molecular studies of mammalian sexual determination have been focused on gene expression in the gonadal ridge at the time of appearance of sexual dimorphism: the critical time defined by the ‘Jost principle’. Three lines of evidence suggest that, instead, sex determination may start shortly after conception: (1) the XY preimplantation embryo usually develops more rapidly than the XX preimplantation embryo (this phenotype has been linked to the Y chromosome and will be termed ‘Growth factor Y’); (2) the gene for (...) testis determination, SRY/Sry, and the closely linked genes ZFY/Zfy and Smcy, are transcribed in the preimplantation embryo; and (3) male and female preimplantation embryos are antigenically distinguishable, indicating sex differences in gene expression. The data to support these assertions are reviewed. Possible relationships of these three phenomena to each other and to sex differentiation are discussed. Similarities in mechanisms of sexual determination between marsupial and eutherian mammals are hypothesized. Problems with interpreting male sexual differentiation as being solely due to testosterone and Müllerian inhibiting substance (MIS) are discussed. (shrink)

Analysis of the mechanisms underlying sex determination and sex differentiation in Drosophila has provided evidence for a complex but comprehensible regulatory hierarchy governing these developmental decisions. It is suggested here that the pattern of sexual differentiation and dosage compensation characteristic of the male is a default regulatory state. Recent results have provided, in addition, some surprising and intriguing conclusions: (1) that several of the critical controlling genes produce more transcripts than was predicted from the genetic analyses; (2) that (...) setting of the alternative sex‐specific states of the doublesex (dsx) locus involves differential transcript processing; and (3) that some aspects of sexual differentation require the prolonged action of certain elements of the regulatory hierarchy. These findings are discussed in connection with the current model of sex determination in Drosophila. (shrink)

Comparative mapping and sequencing show that turnover of sex determining genes and chromosomes, and sex chromosome rearrangements, accompany speciation in many vertebrates. Here I review the evidence and propose that the evolution of therian mammals was precipitated by evolution of the male‐determining SRY gene, defining a novel XY sex chromosome pair, and interposing a reproductive barrier with the ancestral population of synapsid reptiles 190 million years ago (MYA). Divergence was reinforced by multiple translocations in monotreme sex chromosomes, the first of (...) which supplied a novel sex determining gene. A sex chromosome‐autosome fusion may have separated eutherians (placental mammals) from marsupials 160 MYA. Another burst of sex chromosome change and speciation is occurring in rodents, precipitated by the degradation of the Y. And although primates have a more stable Y chromosome, it may be just a matter of time before the same fate overtakes our own lineage. (shrink)

Disorders of sexual differentiation lead to what is often referred to as an intersex state. This state has medical, as well as some legal, recognition. Nevertheless, the question remains whether intersex persons occupy a state in between maleness and femaleness or whether they are truly men or women. To answer this question, another important conundrum needs to be first solved: what defines sex? The answer seems rather simple to most people, yet when morphology does not coincide with haplotypes, and (...) genetics might not correlate with physiology the issue becomes more complex. This paper tackles both issues by establishing where the essence of sex is located and by superimposing that framework onto the issue of the intersex. This is achieved through giving due consideration to the biology of sexual development, as well as through the use of a teleological framework of the meaning of sex. Using a range of examples, the paper establishes that sex cannot be pinpointed to one biological variable but is rather d... (shrink)

Numerous sex differences in obsessive-compulsive disorder (OCD) instantiations are likely universal, as the associated evolutionary threats and concerns onto which they map were differentially important to the two sexes. Hence, although some ritualized behaviors or thoughts are indeed culture-specific, others are both culturally and temporally invariant as they are rooted in universal Darwinian etiologies (e.g., the sex differences in OCD symptomatology posited here). (Published Online February 8 2007).

Between 1946 and 1960, a new phenomenon emerged in the field of bacteriology. "Bacterial sex," as it was called, revolutionized the study of genetics, largely by making available a whole new class of cheap, fast-growing, and easily manipulated organisms. But what was "bacterial sex?" How could single-celled organisms have "sex" or even be sexually differentiated? The technical language used in the scientific press -- the public and inalienable face of 20th century science -- to describe this apparently neuter organism was (...) explicit: the cells "copulated," had "intimate contract," "conjugal unions," and engaged in "ménage à trois" relationships. And yet, to describe bacteria as sexually reproducing organisms, the definition of sex itself had to change. Despite manifold contradictions and the availability of alternative language, the notion of sexually active (even promiscuous) single-celled organisms has persisted, even into contemporary textbooks on cell biology and genetics. In this paper I examine the ways in which bacteria were brought into the genetic fold, sexualized, and given gender; I also consider the issues underlying the durability of "bacterial sex.". (shrink)

Background and purposeWe previously established a radiological protocol to discriminate multiple system atrophy-parkinsonian subtype from Parkinson’s disease. However, we do not know if it can differentiate early stage disease. This study aimed to investigate whether the morphological and intensity changes in susceptibility weighted imaging of the lentiform nucleus could discriminate MSA-P from PD at early stages.MethodsWe retrospectively enrolled patients with MSA-P, PD and sex- and age-matched controls whose brain MRI included SWI, between January 2015 and July 2020 at the Movement (...) Disorder Center. Two specialists at the center reviewed the medical records and made the final diagnosis, and two experienced neuroradiologists performed MRI analysis, based on a defined and revised protocol for conducting morphological measurements of the LN and signal intensity.ResultsNineteen patients with MSA-P and 19 patients with PD, with less than 2 years of disease duration, and 19 control individuals were enrolled in this study. We found that patients with MSA- P presented significantly decreased size in the short line and corrected short line, ratio of the SL to the long line and corrected SLLr of the LN, increased standard deviation of signal intensity compared to patients with PD and controls. With receiver operating characteristic analysis, this finding had a sensitivity of 89.5% and a specificity of 73.7% to distinguish MSA- P from PD.ConclusionCompared to PD and controls, patients with MSA-P are characterized by a narrowing morphology of the posterior region of the LN. Quantitative morphological changes provide a reference for clinical auxiliary diagnosis. (shrink)

The COVID-19 pandemic has caused a global societal, economic, and social upheaval unseen in living memory. There have been substantial cross-national differences in the kinds of policies implemented by political decision-makers to prevent the spread of the virus, to test the population, and to manage infected patients. Among other factors, these policies vary with politicians’ sex: early findings indicate that, on average, female leaders seem more focused on minimizing direct human suffering caused by the SARS-CoV-2 virus, while male leaders implement (...) riskier short-term decisions, possibly aiming to minimize economic disruptions. These sex differences are consistent with broader findings in psychology, reflecting women’s stronger empathy, higher pathogen disgust, health concern, care-taking orientation, and dislike for the suffering of other people—as well as men’s higher risk-taking, Machiavellianism, psychopathy, narcissism, and focus on financial indicators of success and status. This review article contextualizes sex differences in pandemic leadership in an evolutionary framework. Evolution by natural selection is the only known process in nature that organizes organisms into higher degrees of functional order, or counteracts the unavoidable disorder that would otherwise ensue, and is therefore essential for explaining the origins of human sex differences. Differential sexual selection and parental investment between males and females, together with the sexual differentiation of the mammalian brain, drive sex differences in cognition and behavioral dispositions, underlying men’s and women’s leadership styles and decision-making during a global pandemic. According to thesexually dimorphic leadership specialization hypothesis, general psychobehavioral sex differences have been exapted during human evolution to create sexually dimorphic leadership styles. They may be facultatively co-opted by societies and/or followers when facing different kinds of ecological and/or sociopolitical threats, such as disease outbreaks or intergroup aggression. Early evidence indicates that against the invisible viral foe that can bring nations to their knees, the strategic circumspection of empathic feminine health “worriers” may bring more effective and humanitarian outcomes than the devil-may-care incaution of masculine risk-taking “warriors”. (shrink)

ABSTRACT The public controversy over sex‐based differentials in insurance pricing makes heavy use of terms like ‘fairness’ and ‘discrimination’; in particular, both sides argue that their position is the one dictated by considerations of fairness. Appeal to a basic principle of distributive justice shows that these differentials are not fair. Nevertheless, there is a substantial ethical argument to be made for the industry's status quo, based on the liberty of the low‐risk insurees. The paper considers an alternative reform proposal, with (...) a qualitatively different freedom cost; seven factors are then identified as useful in evaluating the trade‐off between the freedom and justice at stake in any questionable insurance classification variable. A brief concluding section attempts to generalise this analysis to provide a broad framework for the analysis of other discrimination issues. (shrink)

Secular change in sex ratios is examined in relation to experience in the family. Two theoretical perspectives are outlined: Guttentag and Secord’s (1983) adaptation of social exchange theory, and sexual selection theory. Because of large-scale change in number of births and typical age differentials between men and women at marriage, low sex ratios at couple formation ages existed in the U.S. between 1965 and the early 1980s. The currently high sex ratios, however, will persist until the end of the century. (...) High sex ratios appear to be associated with lower divorce rates, male commitment to careers that promise economic rewards, male willingness to engage in child care, higher fertility, and higher rates of sexual violence. Sexual selection theory calls attention to intrasexual competition in the numerically larger sex. (shrink)

The finding that women are attracted to men older than themselves whereas men are attracted to relatively younger women has been explained by social psychologists in terms of economic exchange rooted in traditional sex-role norms. An alternative evolutionary model suggests that males and females follow different reproductive strategies, and predicts a more complex relationship between gender and age preferences. In particular, males' preferences for relatively younger females should be minimal during early mating years, but should become more pronounced as the (...) male gets older. Young females are expected to prefer somewhat older males during their early years and to change less as they age. We briefly review relevant theory and present results of six studies testing this prediction. Study 1 finds support for this gender-differentiated prediction in age preferences expressed in personal advertisements. Study 2 supports the prediction with marriage statistics from two U.S. cities. Study 3 examines the cross-generational robustness of the phenomenon, and finds the same pattern in marriage statistics from 1923. Study 4 replicates Study 1 using matrimonial advertisements from two European countries, and from India. Study 5 finds a consistent pattern in marriages recorded from 1913 through 1939 on a small island in the Philippines. Study 6 reveals the same pattern in singles advertisements placed by financially successful American women and men. We consider the limitations of previous normative and evolutionary explanations of age preferences and discuss the advantages of expanding previous models to include the life history perspective. (shrink)

The evidence favoring sex differences in pain seems compelling (berkley). This commentary considers the role of such factors as anxiety, somatosensory amplification, and coping style in accounting for the differential response to pain in the laboratory and clinic, and emphasizes the need to base evaluation and treatment upon individual reports rather than gender-based stereotypes.

O’BYRNE P and WATTS J. Nursing Inquiry 2012 [Epub ahead of print] Include, differentiate and manage: gay male youth, stigma and healthcare utilizationIn Canada, there has been a recent increase in HIV incidence among young men who have sex with men. However, gay male youth (GMY) may forego HIV testing due to fear of stigmatization. Therefore, the aim of this research was to explore the perceptions of stigma in health care within this population. The research was conducted through a series (...) of semi‐structured interviews with eight GMY aged 20–29, who frequented a gay‐friendly clinic in downtown Ottawa, Canada. In a sub‐analysis of the interviews utilizing the work of Hardt and Negri’s three‐part sequence – inclusion, differentiation and management – we found that homosexuality‐related stigmatization affects the interaction between GMY and health professionals. Interview participants perceived HIV‐related risk counselling as a manifestation of stigma. These findings reveal that the experience of stigma and stigmatization is not necessarily based on health professionals’ intentions, but rather, on patients’ perceptions of the interactions they have with health professionals. Specific modifications to the delivery of health care may help to overcome stigmatization. (shrink)

In mammals, the Y chromosome induces testis formation and thus male sexual development; in the absence of a Y chromosome, gonads differentiate into ovaries and female development ensues. Molecular genetic studies have identified the Y‐located testis determining gene SRY as well as autosomal and X‐linked genes necessary for gonadal development. The phenotypes resulting from mutation of these genes, together with their patterns of expression, provide the basis for establishing a hierachy of genes and their interactions in the mammalian sex determination (...) pathway. (shrink)

How is the embryonic bipotential gonad regulated to produce either an ovary or a testis? In males, transient early activation of the Y chromosome Sry gene makes both germ cells and soma male. However, in females, available evidence suggests that the process of ovary sex determination may take place independently in the germline and somatic lineages. In addition, in contrast to testis, in ovary somatic cells, female‐to‐male gonadal sex reversal can occur at times throughout ovary development and maturation. We suggest (...) that a single gene pathway, likely hinging on the Foxl2 transcription factor, both initiates and maintains sex differentiation in somatic cells of the mammalian ovary. BioEssays 29: 15–25, 2007. Published 2006 Wiley Periodicals, Inc. (shrink)

Because men are overrepresented within positions of power, men are perceived as the default in academia. Androcentric bias emerges whereby research by men and/or dominated by men is perceived as higher quality and gains more attention. We examined if these androcentric biases materialize within fields that study bias. How do individuals in close contact with psychology view psychology research outlets with titles including the words women, gender, sex, or feminism or contain the words men or masculinity versus psychology journals that (...) publish other-specialized research, and do these perceptions differ in the general public? While the men-related journal was less meritorious than its other-specialty journal, evidence emerged supporting androcentric bias such that the men-related journal was more favorable than the other sex/gender-related journals. Further, undergraduate men taking psychology classes rated sex/gender-related versus other-specialty journals as less favorable, were less likely to recommend subscription, and rated the journals as lower quality. Low endorsement of feminist ideology was associated with less support for sex/gender-related journals versus matched other-specialty journals. Decreased subscription recommendations for sex/gender-related journals were mediated by decreased favorability and quality beliefs, especially for men and those low in feminist ideology. However, we found possible androcentric-interest within the public sphere. The public reach of articles published in sex/gender-related was greater than other-specialty journals. The consequences of these differential perceptions for students versus the public and the impact on women’s advancement in social science and psychological science are discussed. (shrink)

The finding that women are attracted to men older than themselves whereas men are attracted to relatively younger women has been explained by social psychologists in terms of economic exchange rooted in traditional sex-role norms. An alternative evolutionary model suggests that males and females follow different reproductive strategies, and predicts a more complex relationship between gender and age preferences. In particular, males' preferences for relatively younger females should be minimal during early mating years, but should become more pronounced as the (...) male gets older. Young females are expected to prefer somewhat older males during their early years and to change less as they age. We briefly review relevant theory and present results of six studies testing this prediction. Study 1 finds support for this gender-differentiated prediction in age preferences expressed in personal advertisements. Study 2 supports the prediction with marriage statistics from two U.S. cities. Study 3 examines the cross-generational robustness of the phenomenon, and finds the same pattern in marriage statistics from 1923. Study 4 replicates Study 1 using matrimonial advertisements from two European countries, and from India. Study 5 finds a consistent pattern in marriages recorded from 1913 through 1939 on a small island in the Philippines. Study 6 reveals the same pattern in singles advertisements placed by financially successful American women and men. We consider the limitations of previous normative and evolutionary explanations of age preferences and discuss the advantages of expanding previous models to include the life history perspective. (shrink)

Sex allocation research has primarily focused on offspring sex‐ratio adjustment by mothers. Yet, fathers also benefit from producing more of the sex with greater fitness returns. Here, we review the state‐of‐the art in the study of male‐driven sex allocation and, counter to the current paradigm, we propose that males can adaptively influence offspring sex ratio through a wide variety of mechanisms. This includes differential production and motility of X‐ versus Y‐bearing sperms in mammals, variation in seminal fluid composition in haplo‐diploid (...) invertebrates, and epigenetic mechanisms in some fish and lizards exhibiting environmental sex determination. Conflicts of interest between mothers and fathers over offspring sex ratios can emerge, although many more studies are needed in this area. While many studies of sex allocation have focused on adaptive explanations with little attention to mechanisms, and vice versa, the integration of these two topics is essential for understanding male‐driven sex allocation. (shrink)

Sex is determined by non‐Mendelian genetic elements overriding the sex factors carried by the heterochromosomes in some species of terrestrial isopods. A bacterium Wolbachia and a non‐bacterial feminizing factor (f) can both force chromosomal males of Armadillidium vulgare to become phenotypic functional females. The f factor is believed to be a genetic element derived from the Wolbachia genome that becomes inserted into the host nuclear genome. The feminizing factors can be considered to be selfish genetic elements because they bias their (...) host's sex ratio to increase their own transmission. New sex‐determining genes are selected (genes resisting the feminizing effects, or the transmission of feminizing elements) as a consequence of the conflict between these elements and the rest of the host's genome. These events drive the sex‐determining mechanisms to evolve, and may explain the polymorphism of sex factors and the poor differentiation of the heterochromosomes in isopods. (shrink)

Any sexual offer by a professor to a student is morally problematic. An explicit disclaimer about grading issues will not change the fact that the professor has power over the student’s grades, and no assurance that the student can offer can evade the communicative difficulties created by the power differential. It is possible that there will be a sufficient development of trust that these communication problems are superseded, but it is again extremely difficult to be sure that this is so. (...) Given this difficulty, the criterion for whether the sexual offer is permissible should be whether it is in fact misinterpreted, and the risk that it will be is entirely assumed by the offeror. Even if a fully voluntary sexual relationship is possible, duties to third parties make it improper to enter into such a relationship where the professor has power over a student’s grades or career prospects. (shrink)