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Fořt J, Flegr J, Kuba R, Kaňková Š. Fertility of Czech Gay and Straight Men, Women, and Their Relatives: Testing the Sexually Antagonistic Gene Hypothesis. ARCHIVES OF SEXUAL BEHAVIOR 2024; 53:1747-1761. [PMID: 38472605 PMCID: PMC11106150 DOI: 10.1007/s10508-024-02827-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 03/14/2024]
Abstract
One proposal for the persistence of homosexuality in the human population is the sexually antagonistic gene hypothesis, which suggests that the lower fertility of homosexual individuals, especially men, may be compensated by higher fertility of their relatives of the opposite sex. To test this hypothesis, we have collected data from 7,312 heterosexual men, 459 gay men, 3,352 heterosexual women, and 79 lesbian women mainly from Czechia. In an online survey, participants answered questions regarding their own as well as their parents' and grandparents' fertility. For men, we obtained no significant results except for higher fertility of gay men's paternal grandmothers, but the magnitude of this effect was very small. For the female sample, we recorded lower fertility of lesbian women's mothers and fathers. In line with our expectations, both gay men and lesbian women had lower fertility rates than their heterosexual counterparts. Our results are consistent with recent studies which likewise do not support the sexually antagonistic gene hypothesis.
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Affiliation(s)
- Jakub Fořt
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague, Czechia.
| | - Jaroslav Flegr
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czechia
| | - Radim Kuba
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czechia
- Department of Biology Education, Faculty of Science, Charles University, Prague, Czechia
| | - Šárka Kaňková
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czechia
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2
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Al‐Kuraishy HM, Al‐Maiahy TJ, Al‐Gareeb AI, Alexiou A, Papadakis M, Elhussieny O, Saad HM, Batiha GE. New insights on the potential effect of progesterone in Covid-19: Anti-inflammatory and immunosuppressive effects. Immun Inflamm Dis 2023; 11:e1100. [PMID: 38018575 PMCID: PMC10683562 DOI: 10.1002/iid3.1100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/30/2023] Open
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19) is a pandemic disease caused by severe acute respiratory syndrome CoV type 2 (SARS-CoV-2). COVID-19 is higher in men than women and sex hormones have immune-modulator effects during different viral infections, including SARS-CoV-2 infection. One of the essential sex hormones is progesterone (P4). AIMS This review aimed to reveal the association between P4 and Covid-19. RESULTS AND DISCUSSION The possible role of P4 in COVID-19 could be beneficial through the modulation of inflammatory signaling pathways, induction of the release of anti-inflammatory cytokines, and inhibition release of pro-inflammatory cytokines. P4 stimulates skew of naïve T cells from inflammatory Th1 toward anti-inflammatory Th2 with activation release of anti-inflammatory cytokines, and activation of regulatory T cells (Treg) with decreased interferon-gamma production that increased during SARS-CoV-2 infection. In addition, P4 is regarded as a potent antagonist of mineralocorticoid receptor (MR), it could reduce MRs that were activated by stimulated aldosterone from high AngII during SARS-CoV-2. P4 active metabolite allopregnanolone is regarded as a neurosteroid that acts as a positive modulator of γ-aminobutyric acid (GABAA ) so it may reduce neuropsychiatric manifestations and dysautonomia in COVID-19 patients. CONCLUSION Taken together, the anti-inflammatory and immunomodulatory properties of P4 may improve central and peripheral complications in COVID-19.
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Affiliation(s)
- Hayder M. Al‐Kuraishy
- Department of Clinical Pharmacology and Therapeutic Medicine, College of MedicineMustansiriyah UniversityBaghdadIraq
| | - Thabat J. Al‐Maiahy
- Department of Gynecology and Obstetrics, College of MedicineAl‐Mustansiriyah UniversityBaghdadIraq
| | - Ali I. Al‐Gareeb
- Department of Clinical Pharmacology and Therapeutic Medicine, College of MedicineMustansiriyah UniversityBaghdadIraq
| | - Athanasios Alexiou
- University Centre for Research & DevelopmentChandigarh UniversityMohaliPunjabIndia
- Department of Science and EngineeringNovel Global Community Educational FoundationHebershamNew South WalesAustralia
- Department of Research & DevelopmentAFNP MedWienAustria
| | - Marios Papadakis
- Department of Surgery II, University Hospital Witten‐Herdecke, Heusnerstrasse 40University of Witten‐HerdeckeWuppertalGermany
| | - Omnya Elhussieny
- Department of Histology and Cytology, Faculty of Veterinary MedicineMatrouh UniversityMarsa MatruhEgypt
| | - Hebatallah M. Saad
- Department of Pathology, Faculty of Veterinary MedicineMatrouh UniversityMarsa MatruhEgypt
| | - Gaber El‐Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary MedicineDamanhour University, DamanhourAlBeheiraEgypt
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3
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Sarkar A, Harty S, Johnson KVA, Moeller AH, Carmody RN, Lehto SM, Erdman SE, Dunbar RIM, Burnet PWJ. The role of the microbiome in the neurobiology of social behaviour. Biol Rev Camb Philos Soc 2020; 95:1131-1166. [PMID: 32383208 PMCID: PMC10040264 DOI: 10.1111/brv.12603] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
Microbes colonise all multicellular life, and the gut microbiome has been shown to influence a range of host physiological and behavioural phenotypes. One of the most intriguing and least understood of these influences lies in the domain of the microbiome's interactions with host social behaviour, with new evidence revealing that the gut microbiome makes important contributions to animal sociality. However, little is known about the biological processes through which the microbiome might influence host social behaviour. Here, we synthesise evidence of the gut microbiome's interactions with various aspects of host sociality, including sociability, social cognition, social stress, and autism. We discuss evidence of microbial associations with the most likely physiological mediators of animal social interaction. These include the structure and function of regions of the 'social' brain (the amygdala, the prefrontal cortex, and the hippocampus) and the regulation of 'social' signalling molecules (glucocorticoids including corticosterone and cortisol, sex hormones including testosterone, oestrogens, and progestogens, neuropeptide hormones such as oxytocin and arginine vasopressin, and monoamine neurotransmitters such as serotonin and dopamine). We also discuss microbiome-associated host genetic and epigenetic processes relevant to social behaviour. We then review research on microbial interactions with olfaction in insects and mammals, which contribute to social signalling and communication. Following these discussions, we examine evidence of microbial associations with emotion and social behaviour in humans, focussing on psychobiotic studies, microbe-depression correlations, early human development, autism, and issues of statistical power, replication, and causality. We analyse how the putative physiological mediators of the microbiome-sociality connection may be investigated, and discuss issues relating to the interpretation of results. We also suggest that other candidate molecules should be studied, insofar as they exert effects on social behaviour and are known to interact with the microbiome. Finally, we consider different models of the sequence of microbial effects on host physiological development, and how these may contribute to host social behaviour.
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Affiliation(s)
- Amar Sarkar
- Trinity College, Trinity Street, University of Cambridge, Cambridge, CB2 1TQ, U.K.,Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, U.K
| | - Siobhán Harty
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Dublin, Ireland.,School of Psychology, Trinity College Dublin, Dublin 2, Dublin, Ireland
| | - Katerina V-A Johnson
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K.,Pembroke College, University of Oxford, Oxford, OX1 1DW, U.K.,Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
| | - Andrew H Moeller
- Department of Ecology and Evolutionary Biology, Corson Hall, Tower Road, Cornell University, Ithaca, NY, 14853, U.S.A
| | - Rachel N Carmody
- Department of Human Evolutionary Biology, Harvard University, Peabody Museum, 11 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
| | - Soili M Lehto
- Psychiatry, University of Helsinki and Helsinki University Hospital, PL 590, FI-00029, Helsinki, Finland.,Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, P.O. Box 6, FI-00014, Helsinki, Finland.,Institute of Clinical Medicine/Psychiatry, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Susan E Erdman
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, MA, 02139, U.S.A
| | - Robin I M Dunbar
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K
| | - Philip W J Burnet
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
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4
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Barron AB, Hare B. Prosociality and a Sociosexual Hypothesis for the Evolution of Same-Sex Attraction in Humans. Front Psychol 2020; 10:2955. [PMID: 32010022 PMCID: PMC6976918 DOI: 10.3389/fpsyg.2019.02955] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/12/2019] [Indexed: 12/21/2022] Open
Abstract
Human same-sex sexual attraction (SSSA) has long been considered to be an evolutionary puzzle. The trait is clearly biological: it is widespread and has a strong additive genetic basis, but how SSSA has evolved remains a subject of debate. Of itself, homosexual sexual behavior will not yield offspring, and consequently individuals expressing strong SSSA that are mostly or exclusively homosexual are presumed to have lower fitness and reproductive success. How then did the trait evolve, and how is it maintained in populations? Here we develop a novel argument for the evolution of SSSA that focuses on the likely adaptive social consequences of SSSA. We argue that same sex sexual attraction evolved as just one of a suite of traits responding to strong selection for ease of social integration or prosocial behavior. A strong driver of recent human behavioral evolution has been selection for reduced reactive aggression, increased social affiliation, social communication, and ease of social integration. In many prosocial mammals sex has adopted new social functions in contexts of social bonding, social reinforcement, appeasement, and play. We argue that for humans the social functions and benefits of sex apply to same-sex sexual behavior as well as heterosexual behavior. As a consequence we propose a degree of SSSA, was selected for in recent human evolution for its non-conceptive social benefits. We discuss how this hypothesis provides a better explanation for human sexual attractions and behavior than theories that invoke sexual inversion or single-locus genetic models.
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Affiliation(s)
- Andrew B. Barron
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - Brian Hare
- Department of Evolutionary Anthropology, Center for Cognitive Science, Duke University, Durham, NC, United States
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5
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Chessin K, Lazo A, Strait M, Tate CC. Facilitating and Inhibiting Factors for Self-Reports of Same-Gender Attraction in Cisgender Heterosexual-Identifying Women and Men. JOURNAL OF SEX RESEARCH 2019; 56:1155-1167. [PMID: 31287329 DOI: 10.1080/00224499.2019.1632252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
We sought to identify psychosocial predictors of homoerotic motivations (viz., same-gender attraction) in heterosexual identifying cisgender women and men. We recruited participants from Amazon's Mechanical Turk to complete measures of (a) antipathy towards lesbians and gay men, (b) gender role beliefs, (c) felt-pressure to conform to gender stereotypes, and (d) openness to experience. In Study 1, we found that same-gender attraction was (a) negatively related to antipathy towards same-gender homosexual targets and (b) positively related to felt-pressure to conform to gender stereotypes for both women and men. In Study 2, both effects replicated for men at p < .05, but women only showed the antipathy effect at p < .05, even while the felt-pressure effect size was similar to that in Study 1. Additionally, men showed a significant negative relationship between openness and same-gender attraction. Thus, both anti-gay attitudes and felt-pressure to conform to gender stereotypes appear to be reliably associated with same-gender attraction.
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Affiliation(s)
- Kris Chessin
- Department of Psychology, San Francisco State University
| | - Andreana Lazo
- Department of Psychology, San Francisco State University
| | - Megan Strait
- Department of Psychology, San Francisco State University
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Dutra E, Lee J, Torbati T, Garcia M, Merz CNB, Shufelt C. Cardiovascular implications of gender-affirming hormone treatment in the transgender population. Maturitas 2019; 129:45-49. [PMID: 31547912 PMCID: PMC6761990 DOI: 10.1016/j.maturitas.2019.08.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 01/25/2023]
Abstract
Transgender men and women represent a growing population in the United States and Europe, with 0.5% of adults and 3% of youth identifying as transgender. Globally, an estimated 0.3-0.5% of the population identify as transgender. Despite the increasing percentage of individuals whose gender identity, gender expression and behavior differ from their assigned sex at birth, health outcomes in transgenders have been understudied. Many transgender people seek treatment with cross-sex hormone therapy starting from a young age and frequently at high doses in order to obtain the secondary sex characteristics of the desired gender. There is a need to understand the potential long-term health consequences of cross-sex hormone therapy, given that cardiovascular disease is the leading disease-specific cause of death in this population. This review discusses the cardiovascular risks of gender-affirming hormone treatments with respect to transgender women and transgender men.
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Affiliation(s)
- Erika Dutra
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Julie Lee
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Tina Torbati
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Maurice Garcia
- Division of Urology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, United States; Cedars-Sinai Transgender Surgery and Health Program, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - C Noel Bairey Merz
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Chrisandra Shufelt
- Barbra Streisand Women's Heart Center, Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States.
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7
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Luoto S, Krams I, Rantala MJ. A Life History Approach to the Female Sexual Orientation Spectrum: Evolution, Development, Causal Mechanisms, and Health. ARCHIVES OF SEXUAL BEHAVIOR 2019; 48:1273-1308. [PMID: 30229521 DOI: 10.1007/s10508-018-1261-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 05/29/2018] [Accepted: 06/14/2018] [Indexed: 05/12/2023]
Abstract
Women's capacity for sexual fluidity is at least as interesting a phenomenon from the point of view of evolutionary biology and behavioral endocrinology as exclusively homosexual orientation. Evolutionary hypotheses for female nonheterosexuality have failed to fully account for the existence of these different categories of nonheterosexual women, while also overlooking broader data on the causal mechanisms, physiology, ontogeny, and phylogeny of female nonheterosexuality. We review the evolutionary-developmental origins of various phenotypes in the female sexual orientation spectrum using the synergistic approach of Tinbergen's four questions. We also present femme-specific and butch-specific hypotheses at proximate and ultimate levels of analysis. This review article indicates that various nonheterosexual female phenotypes emerge from and contribute to hormonally mediated fast life history strategies. Life history theory provides a biobehavioral explanatory framework for nonheterosexual women's masculinized body morphology, psychological dispositions, and their elevated likelihood of experiencing violence, substance use, obesity, teenage pregnancy, and lower general health. This pattern of life outcomes can create a feedback loop of environmental unpredictability and harshness which destabilizes intrauterine hormonal conditions in mothers, leading to a greater likelihood of fast life history strategies, global health problems, and nonheterosexual preferences in female offspring. We further explore the potential of female nonheterosexuality to function as an alloparental buffer that enables masculinizing alleles to execute their characteristic fast life history strategies as they appear in the female and the male phenotype. Synthesizing life history theory with the female sexual orientation spectrum enriches existing scientific knowledge on the evolutionary-developmental mechanisms of human sex differences.
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Affiliation(s)
- Severi Luoto
- English, Drama and Writing Studies, University of Auckland, Arts 1, Building 206, Room 616, 14A Symonds St., Auckland, 1010, New Zealand.
- School of Psychology, University of Auckland, Auckland, New Zealand.
| | - Indrikis Krams
- Department of Zoology and Animal Ecology, University of Latvia, Riga, Latvia
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Markus J Rantala
- Department of Biology & Turku Brain and Mind Center, University of Turku, Turku, Finland
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8
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Gangestad SW, Grebe NM. Hormonal systems, human social bonding, and affiliation. Horm Behav 2017; 91:122-135. [PMID: 27530218 DOI: 10.1016/j.yhbeh.2016.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 08/04/2016] [Accepted: 08/12/2016] [Indexed: 12/20/2022]
Abstract
Which hormones are implicated in human social bonding and affiliation? And how does field research speak to this issue? We begin by laying out a broad view of how endocrine hormones in general modulate life history allocations of energy and other resources, and the ways in which their neuromodulatory functions must be understood within a broader conceptualization of how they have been shaped to affect allocations. We then turn to four specific hormones or hormone families that have received much attention: oxytocin, opioids, prolactin, and progesterone. Each plays a role in regulating psychological capacities and propensities that underlie individuals' interactions with important social targets. Yet in no case is it clear exactly what regulatory roles these hormones play. We suggest several directions for future research.
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Affiliation(s)
- Steven W Gangestad
- Department of Psychology, University of New, Albuquerque, NM 87111, Mexico.
| | - Nicholas M Grebe
- Department of Psychology, University of New, Albuquerque, NM 87111, Mexico
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9
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Stief M. The Sexual Orientation and Gender Presentation of Hijra, Kothi, and Panthi in Mumbai, India. ARCHIVES OF SEXUAL BEHAVIOR 2017; 46:73-85. [PMID: 27878410 DOI: 10.1007/s10508-016-0886-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Cultural categories related to sexuality and gender vary considerably cross-culturally. While Western cultures categorize people primarily in terms of sexual attractions (i.e., gay, straight, bisexual), many cultures distinguish between groups based on additional issues such as gender role presentation and position preference in anal sex (i.e., insertive/receptive). The current study gathered data on three categories of natal males in Mumbai, India-hijra, kothi, and panthi (N = 93). Hijra are androphilic (sexually attracted to adult men), typically sexually receptive, transgender, sometimes castrated, and live in fictive kinship networks that are hierarchically organized. Kothi are also androphilic, typically sexual receptive and relatively feminine but less so than hijra; unlike hijra, kothi are never castrated. Hijra and kothi were understood by some participants to be mutually compatible, and so three groups were identified-those endorsing hijra only (n = 11), kothi only (n = 22), and both hijra and kothi (n = 22). Panthi (n = 38) are the masculine insertive partners of hijra and kothi. Measures employed were self-report and viewing time measures of sexual attraction, sexual behavior and position preference, self-described masculinity/femininity, recalled childhood gender atypicality, gendered occupational preferences, and gender presentation milestones (i.e., wearing female clothes, castration). All hijra and kothi groups were found to be exclusively androphilic in viewing time and self-reported sexual attractions, and to be gender-atypical on all measures. Panthi were found to be relatively male-typical and to have a bisexual pattern of viewing time and self-reported sexual attractions. Kothi were found to be less extreme in their female typicality and to report less female gender presentation milestones than hijra or hijra/kothi. Most hijra and hijra/kothi and all kothi said that they were not castrated. Contrary to the manner in which they are socially defined, a third of panthi report having been receptive in anal sex, and a third of all hijra and kothi groups report having been insertive at some time.
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Affiliation(s)
- Matthew Stief
- Department of Human Development, Cornell University, G77 Martha Van Rensselaer Hall, Ithaca, NY, 14853, USA.
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10
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Safron A. What is orgasm? A model of sexual trance and climax via rhythmic entrainment. SOCIOAFFECTIVE NEUROSCIENCE & PSYCHOLOGY 2016; 6:31763. [PMID: 27799079 PMCID: PMC5087698 DOI: 10.3402/snp.v6.31763] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 01/07/2023]
Abstract
Orgasm is one of the most intense pleasures attainable to an organism, yet its underlying mechanisms remain poorly understood. On the basis of existing literatures, this article introduces a novel mechanistic model of sexual stimulation and orgasm. In doing so, it characterizes the neurophenomenology of sexual trance and climax, describes parallels in dynamics between orgasms and seizures, speculates on possible evolutionary origins of sex differences in orgasmic responding, and proposes avenues for future experimentation. Here, a model is introduced wherein sexual stimulation induces entrainment of coupling mechanical and neuronal oscillatory systems, thus creating synchronized functional networks within which multiple positive feedback processes intersect synergistically to contribute to sexual experience. These processes generate states of deepening sensory absorption and trance, potentially culminating in climax if critical thresholds are surpassed. The centrality of rhythmic stimulation (and its modulation by salience) for surpassing these thresholds suggests ways in which differential orgasmic responding between individuals-or with different partners-may serve as a mechanism for ensuring adaptive mate choice. Because the production of rhythmic stimulation combines honest indicators of fitness with cues relating to potential for investment, differential orgasmic response may serve to influence the probability of continued sexual encounters with specific mates.
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Affiliation(s)
- Adam Safron
- Department of Psychology, Northwestern University, Evanston, IL, USA;
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11
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Fleischman DS. An evolutionary behaviorist perspective on orgasm. SOCIOAFFECTIVE NEUROSCIENCE & PSYCHOLOGY 2016; 6:32130. [PMID: 27799083 PMCID: PMC5087694 DOI: 10.3402/snp.v6.32130] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/20/2016] [Accepted: 09/23/2016] [Indexed: 11/15/2022]
Abstract
Evolutionary explanations for sexual behavior and orgasm most often posit facilitating reproduction as the primary function (i.e. greater rate of fertilization). Other reproductive benefits of sexual pleasure and orgasm such as improved bonding of parents have also been discussed but not thoroughly. Although sex is known to be highly reinforcing, behaviorist principles are rarely invoked alongside evolutionary psychology in order to account for human sexual and social behavior. In this paper, I will argue that intense sexual pleasure, especially orgasm, can be understood as a primary reinforcer shaped by evolution to reinforce behavior that facilitates reproductive success (i.e. conception through copulation). Next, I will describe an evolutionary account of social shaping. In particular, I will focus on how humans evolved to use orgasm and sexual arousal to shape the social behavior and emotional states of others through both classical and operant conditioning and through both reproductive and non-reproductive forms of sexual behavior. Finally, I will describe how orgasm is a signal of sensitivity to reinforcement that is itself reinforcing.
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Affiliation(s)
- Diana S Fleischman
- Department of Psychology, University of Portsmouth, Hampshire, United Kingdom;
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12
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Juster RP, Almeida D, Cardoso C, Raymond C, Johnson PJ, Pfaus JG, Mendrek A, Duchesne A, Pruessner JC, Lupien SJ. Gonads and strife: Sex hormones vary according to sexual orientation for women and stress indices for both sexes. Psychoneuroendocrinology 2016; 72:119-30. [PMID: 27398882 DOI: 10.1016/j.psyneuen.2016.06.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 06/14/2016] [Accepted: 06/15/2016] [Indexed: 12/18/2022]
Abstract
This study assessed sexual orientation and psychobiological stress indices in relation to salivary sex hormones as part of a well-validated laboratory-based stress paradigm. Participants included 87 healthy adults that were on average 25 years old who self-identified as lesbian/bisexual women (n=20), heterosexual women (n=21), gay/bisexual men (n=26), and heterosexual men (n=20). Two saliva samples were collected fifteen minutes before and fifteen minutes after exposure to a modified Trier Social Stress Test to determine testosterone, estradiol, and progesterone concentrations via enzyme-immune assaying. Mean sex hormones were further tested in association to stress indices related to cortisol systemic output (area under the curve with respect to ground) based on ten measures throughout the two-hour visit, allostatic load indexed using 21 biomarkers, and perceived stress assessed using a well-validated questionnaire. Results revealed that lesbian/bisexual women had higher overall testosterone and progesterone concentrations than heterosexual women, while no differences were found among gay/bisexual men in comparison to heterosexual men. Lesbian/bisexual women and heterosexual men showed positive associations between mean estradiol concentrations and allostatic load, while gay/bisexual men and heterosexual women showed positive associations between mean testosterone and cortisol systemic output. In summary, sex hormone variations appear to vary according to sexual orientation among women, but also as a function of cortisol systemic output, allostatic load, and perceived stress for both sexes.
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Affiliation(s)
- Robert-Paul Juster
- Department of Psychiatry, Columbia University, New York, NY, United States.
| | - Daniel Almeida
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | | | - Catherine Raymond
- Départment de Neuroscience, Université de Montréal, Montreal, Quebec, Canada
| | - Philip Jai Johnson
- Department of Psychiatry, Columbia University, New York, NY, United States
| | - James G Pfaus
- Department of Psychology, Concordia University, Montreal, Quebec, Canada
| | - Adrianna Mendrek
- Départment de Psychiatrie, Université de Montréal, Montreal, Quebec, Canada; Department of Psychology, Bishop's University, Sherbrooke, Quebec, Canada
| | - Annie Duchesne
- Department of Psychology, Bishop's University, Sherbrooke, Quebec, Canada
| | - Jens C Pruessner
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada; Department of Psychology, McGill University, Montreal, Quebec, Canada
| | - Sonia J Lupien
- Départment de Psychiatrie, Université de Montréal, Montreal, Quebec, Canada
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13
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Apostolou M. The evolution of same-sex attractions: Parental and intimate partners' reactions to deviations from exclusive heterosexual orientation. PERSONALITY AND INDIVIDUAL DIFFERENCES 2016. [DOI: 10.1016/j.paid.2016.06.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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