The evolution of female sexuality and mate selection in humans

Understanding female sexuality and mate choice is central to evolutionary scenarios of human social systems. Studies of female sexuality conducted by sex researchers in the United States since 1938 indicate that human females in general are concerned with their sexual well-being and are capable of sexual response parallel to that of males. Across cultures in general and in western societies in particular, females engage in extramarital affairs regularly, regardless of punishment by males or social disapproval. Families are usually concerned with marriage arrangements only insofar as those arrangements are economically or politically advantageous, but females most often have a voice in arranged marriages. Extended families also concentrate on a couple’s future reproduction rather than on sexual exclusivity. Although marriage for females is often compromised by male or family reproductive interests (which may not in fact differ from female interests), females appear to exercise their sexuality with more freedom than has previously been suggested. Notions of human females as pawns in the male reproductive game, or as traders of sex for male services, should be dispelled.     

A proposal on a contribution of space biological sciences to sexual health in the human space life.

Sexuality is a basic property of the human being and provides an important background for the human life and society. The present situation in the world strongly suggests that the human being will extensively and intensively spread out in space and the population in space, particularly on the space stations in orbit, moon and possibly Mars, will rapidly increase during this century. Therefore sexual health will become a serious issue for the development of space and a better life of the human in the space environment. It is not too early to consider sexuality in the space life and to discuss how to maintain sexual health, how to control it in the space society, or whether it should be controlled. Space biological sciences should be the key and play an important role in studying scientifically sexuality especially the sex, sexual behavior and reproduction in the space environment.     

Male-female differences in the effects of cannabinoids on sexual behavior and gonadal hormone function

The putative role of the endocannabinoid system and the effects of cannabis use in male and female sexual functioning are summarized. The influence of cannabis intake on sexual behavior and arousability appear to be dose-dependent in both men and women, although women are far more consistent in reporting facilitatory effects. Furthermore, evidence from nonhuman species indicate somewhat more beneficial than debilitating effects of cannabinoids on female sexual proceptivity and receptivity while suggesting predominantly detrimental effects on male sexual motivation and erectile functioning. Data from human and nonhuman species converge on the ephemeral nature of THC-induced testosterone decline. However, it is clear that cannabinoid-induced inhibition of male sexual behavior is independent of concurrent declines in testosterone levels. Investigations also reveal a suppression of gonadotropin release by cannabinoids across various species. Historical milestones and promising future directions in the area of cannabinoid and sexuality research are also outlined in this review.     

Loss of estrus in human evolution: Too many answers,too few questions

Models addressing the importance of “loss of estrus” in human evolution assume that, as part of a general trend among higher primates, endogenous hormonal fluctuations have less influence on human female sexuality than cognitive and socioenvironmental factors. The diversity of reproductive patterns among primate species is not satisfactorily explained as the outcome of evolutionary trends along dimensions such as brain enlargement, behavioral flexibility, or relative independence of behavior from physiology. Rather, the role of hormones and other factors must be viewed in the context of species' life history and ecological constraints. Human studies on the relationship between the menstrual cycle and sexual behavior have been limited to Western women in industrialized societies, which may not reveal evolved behavioral-physiological patterns. Furthermore, available studies have yielded inconsistent results. No single pattern emerges that can be said to characterize the human female, and no conclusion can be reached regarding the relationship between cyclic hormonal fluctuations and sexual behavior and, thus, whether human ovulation is concealed. Future studies are needed that are methodologically improved and systematically document the interaction among ecological, subsistence, social, and physiological variables.     

A PSYCHIATRIC EVALUATION OF THE KINSEY REPORT

In Kinsey''s investigations there seems to be a tendency to study human sexuality from a biological point of view and to neglect the psychological with which sexuality is intimately involved. He does not sufficiently differentiate between sexual behavior in animals and humans which appear to be similar but which are really very different. His sociological conclusions suffer from this limited approach. Experience with patients strongly suggests that his statistics on women may include gross distortion. From a clinical psychiatric standpoint his concept of perversions is oversimplified. To Kinsey, all sexual activity represents the expression of sexual desire whereas it not uncommonly may be used to relieve tensions which are not of sexual origin.     

The evolutionary psychology of sexual harassment in organizations

We explore the value of theory developed in the field of evolutionary psychology for predicting and explaining patterns of sociosexual interaction between men and women in the workplace. In particular, we focus on assessing the value of this theoretical framework for increasing our understanding of the behavioral phenomenon of sexual harassment in organizations. To do this, we develop hypotheses based on a consideration of the evolved psychological mechanisms which have been proposed by evolutionary psychologists to underly human sexual behavior. We then review the existing literature on sociosexual behavior and sexual harassment within the workplace as a preliminary test of predictions concerning the expected profile, reaction, and motivation of recipients and initiators of sexual advances in the workplace. We also analyze the expected effect of novel aspects of the organizational environment on overt sexual behavior. This theory predicts, for example, that most sexual harassment will be initiated by men, and that young, single women will be the most frequent victims. This theory also predicts that women will generally experience a more negative reaction than men to sexual advances in the workplace, but that this emotional response will be mediated by other factors such as the profile of the initiator. The available data generally confirm these and other related predictions. Moreover, these results are quite consistent with other studies of the evolutionary psychology of human sexuality. We discuss the implications for theory in this area, and suggest some potentially fruitful avenues for original empirical research on human sexual behavior, inside or outside the workplace.     

Differential use of sensory information in sexual behavior as a function of gender

Olfactory information is critical to mammalian sexual behavior. Based on parental investment theory the relative importance of olfaction compared with vision, touch, and hearing should be different for human males and females. In particular, because of its link to immunological profile and offspring viability, odor should be a more important determinant of sexual choice and arousal for females than for males. To test this hypothesis a questionnaire was developed and administered to 332 adults (166 males, 166 females). Subjects used a 1–7 scale to indicate how much they agreed with a series of statements concerning the importance of olfactory, visual, auditory, and tactile information for their sexual responsivity. The data reveal that males rated visual and olfactory information as being equally important for selecting a lover, while females considered olfactory information to be the single most important variable in mate choice. Additionally, when considering sexual activity, females singled out body odor from all other sensory experiences as most able to negatively affect desire, while males regarded odors as much more neutral stimuli for sexual arousal. The present results support recent findings in mice and humans concerning the relation of female preferences in body odor and major histocompatibility complex (MHC) compatibility and can be explained by an evolutionary analysis of sex differences in reproductive strategies. This work represents the first direct examination of the role of different forms of sensory information in human sexual behavior.     

Health Risks in Same-Sex Attracted Ugandan University Students: Evidence from Two Cross-Sectional Studies

Widespread discrimination across much of sub-Saharan Africa against persons with same-sex sexuality, including recent attempts in Uganda to extend criminal sanctions against same-sex behavior, are likely to have profound effects on this group’s health, health care access, and well-being. Yet knowledge of the prevalence of same-sex sexuality in this region is scarce. This study aimed to systematically examine prevalence of same-sex sexuality and related health risks in young Ugandan adults. We conducted two cross-sectional survey studies in south-western Uganda targeting student samples (n = 980, n = 1954) representing 80% and 72% of the entire undergraduate classes attending a university in 2005 and 2010, respectively. A questionnaire assessed items concerning same-sex sexuality (same-sex attraction/fantasies, same-sex sexual relations), mental health, substance use, experience of violence, risky sexual behavior, and sexual health counseling needs. Our findings showed that same-sex sexual attraction/fantasies and behavior were common among male and female students, with 10–25% reporting having sexual attraction/fantasies regarding persons of the same-sex, and 6–16% reporting same-sex sexual relations. Experiences of same-sex sexuality were associated with health risks, e.g. poor mental health (2010, AOR = 1.5; 95% CI: 1.0–2.3), sexual coercion (2010, AOR 2.9; CI: 1.9–4.6), and unmet sexual health counseling needs (2010, AOR 2.2; CI: 1.4–3.3). This first study of young adults in Uganda with same-sex sexuality found high levels of health needs but poor access to health care. Effective response is likely to require major shifts in current policy, efforts to reduce stigmatization, and reorientation of health services to better meet the needs of this vulnerable group of young people.     

Interactionism and Innateness in the Evolutionary Study of Human Nature

While most researchers who use evolutionary theory to investigatehuman nature especially human sexuality describe themselves as ``interactionists', there is no clear consensus on the meaning of thisterm in this context. By interactionism most people in the fieldmean something like, both nature and nurture ``count' in thedevelopment of human psychology and behavior. Nevertheless, themultidisciplinary nature of evolutionary psychology results in a widevariety of interpretations of this general claim. Today, mostdebates within evolutionary psychology about the innateness of agiven behavioral characteristic or over its development turn as muchon which conception of ``innateness' and ``interactionism' theresearcher holds as on any empirical data they might derive.     

The consequences of facultative sex in a prey adapting to predation

A species reproductive mode, along with its associated costs and benefits, can play a significant role in its evolution and survival. Facultative sexuality, being able to reproduce both sexually and asexually, has been deemed evolutionary favourable as the benefits of either mode may be fully realized. In fact, many studies have focused on identifying the benefits of sex and/or the forces selecting for increased rates of sex using facultative sexual species. The costs of either mode, however, can also have a profound impact on a population's evolutionary trajectory. Here, we used experimental evolution and fitness assays to investigate the consequences of facultative sexuality in prey adapting to predation. Specifically, we compared the adaptive response of algal prey populations exposed to constant rotifer predation and which had alternating cycles of asexual and sexual reproduction where sexual episodes were either facultative (sexual and asexual progeny simultaneously propagated) or obligate (only sexual progeny propagated). We found that prey populations with facultative sexual episodes reached a lower final relative fitness and suffered a greater trade‐off in traits under selection, that is defence and competitive ability, as compared to prey populations with obligate sexual episodes. Our results suggest that costs associated with sexual reproduction (germination time) and asexual reproduction (selection interference) were amplified in the facultative sexual prey populations, leading to a reduction in the net advantage of sexuality. Additionally, we found evidence that the cost of sex was reduced in the obligate sexual prey populations because increased selection for sex was observed via the spontaneous production of sexual cells. These results show that certain costs associated with facultative sexuality can affect an organism's evolutionary trajectory.     

The ‘SONY NIGHTCLUB’: Rural Brothels,Gender Violence,and Development in Coastal Ecuador

ABSTRACT

In the Ecuadorian public imaginary, Manabí province is constructed as a lawless frontier. Manaba men are characterized for their aggressive masculinity, robust and primitive sexuality, and their proclivity towards resolving conflict with violence. This paper examines community debates about brothels and healthy sexuality in a rural coastal region where the state is expanding its reach into domestic life via the regulation of sexual intimacies and family violence. Local debates about healthy sexuality embody the historically contested and currently changing nature of state–community relationships in this previously marginalized region. While certain community factions invoke modernizing discourses of women's rights in their struggle to shut down brothels and mitigate family violence, others argue for unregulated sexuality as a way to diminish violence. Drawing from over 10 years of ethnographic research on gender, violence, and human rights in Ecuador, this paper reveals the co-construction of rural intimacies and the boundaries of state intervention.     

Retentissement sexuel, conjugal et social d’une population d’hommes stériles consultants en Andrologie: le point de vue du psychiatre de liaison

Material and methods

The study population consisted of 39 subjects divided into two groups: 21 azoospermic males and 18 oligoazoospermic males. These men were selected in andrology departments over a period of six months. The andrology and liaison psychiatry departments of Lille university hospital established a general infertility questionnaire. This semi-structured questionnaire comprising 40 questions was based on clinical experience and describes the clinical and symptomatic context of infertility. An individual 50-item questionnaire was then used to analyse the psychosocial, marital and sexual effects of male infertility and the representation of the psychiatrist in the andrology department.

Results

One third of patients discovered the diagnosis of infertility when the biologist gave them the results of the semen analysis. Our patients initially envisaged marital, psychological and social problems, but very few sexual problems. They imagined that infertility was more disturbing for women than for men, from a psychological and sexual point of view. 82% of our subjects imagined that their partner had no sexual problems. 48.7% of them thought that their partner had no psychological difficulties related to their infertility. The oligoasthenospermia group considered that the partner had significantly more “psychological difficulties” compared to the azoospermia group. 41% of our patients felt guilty towards their partner because of their infertility diagnosis. 10.3% of patients presented sexual disorders before the diagnosis of male infertility and 25.6% presented sexual disorders after this diagnosis. Contrary to data in the literature, a major change of sexuality was not observed in the majority of the couples after the diagnosis. When sexuality changed, it generally consisted of a reduction of the frequency of sexual relations. Among the patients who reported sexual difficulties, only 40% related them to infertility. 50% did not report any relationship between the psychological difficulties related to infertility and the sexual difficulties. Contrary to the data in the literature, neither the loss of spontaneity during sexual relations, nor the complementary investigations necessary for artificial insemination had any influence on sexuality. 89.8% of our patients are ready to change their sexual practices in order to be more fertile without causing any sexual or psychological problems. However, only 34.3% of patients reported a concern about reproductive efficacy during sexual relations. A more marked sexuality/reproduction dissociation was observed in oligoazoospermic males than in azoospermic males. 28.2% of patients reported that talking about their sexual and/or psychological problems with a psychiatrist was helpful.

Conclusion

Many contradictions and underestimations were observed in the answers to the questions. We confirmed the existence of a psychological and sexual distress, but which was quantitatively less severe than that described in “gynaecological” populations. However, a real psychological and sexual distress does exist in our population, which is why we propose from the outset a psychosomatic and sexological treatment of infertility in order to prevent the onset of these sexual difficulties. Our questionnaire was based on clinical experience and helped our patients to identify their psychological and sexual difficulties related to infertility and its treatment. It would therefore be useful for the practitioner, andrologist or psychiatrist, to help the patient express the effects related to this “new medicalized sexuality”.     

Endocrinology of human female sexuality,mating, and reproductive behavior

Hormones orchestrate and coordinate human female sexual development, sexuality, and reproduction in relation to three types of phenotypic changes: life history transitions such as puberty and childbirth, responses to contextual factors such as caloric intake and stress, and cyclical patterns such as the ovulatory cycle. Here, we review the endocrinology underlying women's reproductive phenotypes, including sexual orientation and gender identity, mate preferences, competition for mates, sex drive, and maternal behavior. We highlight distinctive aspects of women's sexuality such as the possession of sexual ornaments, relatively cryptic fertile windows, extended sexual behavior across the ovulatory cycle, and a period of midlife reproductive senescence—and we focus on how hormonal mechanisms were shaped by selection to produce adaptive outcomes. We conclude with suggestions for future research to elucidate how hormonal mechanisms subserve women's reproductive phenotypes.     

Relations de pouvoir et égalitarisme sexuel chez un groupe d'étudiants marocains

In order to verify what are the differences in the field of power relations, equality in the sphere of sexual roles as well as the control of sexual drives among young Moroccans, 111 university students (50 men and 61 women) have answered an anonymous self-administred questionnaire dealing with their sexual lives. Statistical results show that for both sexes, sexuality appears more as a sharing experience than a power one. Both sexes consider also that it is the prerogative of men to initiate sexual relations as well to decide the use of condom. Men consider that they are more able to express their sexual demands than women. The latter are more in control of their sexual drives and of the modulation of their sexual life. The results indicate also the presence of a sexual double standard with men being more sexually active than women. These data confirm on the whole the qualitative data provided by anthropological research on sexuality in Morocco.     

The evolution of human sexuality

The study of human sexuality from the darwinian perspective is in an explosive phase. Recent research is diverse; for instance, the dynamics of heterosexual relationships, the role of honest advertisement in attractiveness, the role of fluctuating asymmetry in sexual competition, and sexual conflict over fertilization, seen in sperm competition adaptations of men and possible cryptic sire-choice adaptation of women. Also, recent research reveals that the sexual selection that designed human secondary sexual traits was functional rather than strictly fisherian.     

Women’s sexual strategies in pregnancy

Humans exhibit an unusual pattern of sexual behavior compared to other mammalian females. Women's extended sexuality has been hypothesized to be related to a variety of possible benefits, especially non-genetic reproductive benefits, such as securing male investment via reinforced pairbonds or paternity confusion. But sexual behavior also comes at a cost, particularly for pregnant women, in terms of energetic costs, potential disease, and possible harm to the fetus. We hypothesize, therefore, that sexual behavior in pregnant women should reflect adaptive strategies and that pregnant women will be particularly strategic about their sexual behavior in order to maximize potential benefits while minimizing potential costs. One hundred twelve pregnant women completed a survey of their partners' qualities and their sexual desires toward their primary partners and men other than their primary partners. Results showed that women's perceptions of relationship threat positively predicted sexual desire for primary partners, while their perceptions of their partner's investing qualities negatively predicted sexual desire for extra-pair mates. These qualities, as well as cues to partner's genetic quality and gestation age, also interacted in ways that suggest that pregnant women's sexual desires are sensitive to cues of future investment and relationship stability.     

The primate origins of female sexuality,and their implications for the role of nonconceptive sex in the reproductive strategies of women

In many species of monkeys and apes, sexual solicitations of males by females are more facultative and opportunistic than generally realized. Although female sexual solicitations peak at midcyle, solicitations and copulations are not necessarily confined to the days just around ovulation. Human female sexuality, and the physiological underpinnings of this sexuality evolved in prehominid contexts in which female primates solicited and copulated with multiple males on a situation-dependent basis. Such sexual behavior became increasingly costly to females in the course of hominid evolution, and women's sexuality today must be viewed as an imperfect compromise between formerly adaptive organs (such as the female clitoris) and the chronic challenges mothers face in eliciting and insuring male protection and investment in offspring.     

Julian M. Davidson. (April 15, 1931-December 31, 2001)

Julian Davidson was one of the three founding editors (with Frank A. Beach and Richard E. Whalen) of Hormones and Behavior and served in this capacity from 1969 to 1976. In addition, Julian made many significant research contributions to the field of behavioral neuroendocrinology. These included his studies on the neuroendocrine control of masculine sexual behavior, first in the rat and later in the human male. Julian Davidson was one of a small number of investigators who successfully bridged the divide between animal and human studies of sexuality and brain function. In light of his contributions to our field and his instrumental role in the creation of this journal, we are publishing a collection of remembrances by former students and fellows as well as colleagues and friends. Benjamin Sachs has overseen the solicitation and editing of these contributions.Michael J. Baum Editor     

Measuring Gender

Over the past several years, various operational definitions of gender have been used in studies of gender conformity in homosexual males. The goal of these studies is to demonstrate that childhood gender nonconformity (CGN) is either the proximate cause of adult homosexuality or an intermediate step in a biologically mediated process. The hypothesis of a causal connection between the development of gender and sexual orientation is embedded within the context of a biological (evolutionary) understanding of human behavior. Thus, testing the hypothesis of a causal connection between CGN and sexuality requires a concept of gender that is compatible with the basic principles of biological causation and our current understanding of evolutionary processes. I will argue that the concepts of gender used in the attempt to demonstrate a causal connection between CGN and sexual orientation are inappropriate because they provide no uniform, consistent method for identifying and measuring the biologically significant components of gender. I will also argue that the concept of gender that does emerge from these studies suggests an hypothesis about the connection between sexuality and gender that is not consistent with the cross-gendered theory of the etiology of homosexuality.