scholarly journals Oral Sex, Semen Displacement, and Sexual Arousal: Testing the Ejaculate Adjustment Hypothesis

2013 ◽  
Vol 11 (5) ◽  
pp. 147470491301100 ◽  
Author(s):  
Michael N. Pham ◽  
Todd K. Shackelford ◽  
Lisa L. M. Welling ◽  
Alyse D. Ehrke ◽  
Yael Sela ◽  
...  
Keyword(s):  
Sperm Competition ◽  
Sexual Arousal ◽  
Sexual Behaviors ◽  
Copulatory Behavior ◽  
Oral Sex ◽  
Regular Partner ◽  
Sexual Encounter ◽  
Competition Theory ◽  
Heterosexual Relationship

Male Indian Flying Foxes ( Pteropus giganteus) that spend more time performing oral sex on a female also spend more time copulating with her. In humans, men who spend more time copulating with their regular partner also perform more “semen-displacing” copulatory behaviors (e.g., deeper, more vigorous penile thrusting). We investigated whether men who spend more time performing oral sex on their regular partner also spend more time copulating with her and perform more semen-displacing copulatory behaviors. We proposed and tested the ejaculate adjustment hypothesis for men's copulatory behaviors: Men adjust their copulatory behaviors to increase their sexual arousal and consequent ejaculate quality, thereby increasing their chances of success in sperm competition. Two hundred and thirty-three men in a committed, heterosexual relationship responded to questions about their copulatory behavior and sexual arousal during their most recent sexual encounter with their long-term partner. The results indicated that men who spend more time performing oral sex on their partner also spend more time copulating with her, perform more semen-displacing copulatory behaviors, and report greater sexual arousal. We discuss limitations to the current research and highlight the heuristic value of sperm competition theory for understanding human sexual behaviors.

2. The Effects of Sociosexual Orientation, Gender and Relationship Context Cues in Audio Narratives on Heterosexual Men's Genital and Subjective Sexual Response.

2016 ◽  
Author(s):  
Jenna Brandon
Keyword(s):  
Sexual Arousal ◽  
Past Research ◽  
Sexual Partners ◽  
Specific Pattern ◽  
Sexual Relationships ◽  
Heterosexual Men ◽  
Sexual Encounter ◽  
Relationship Context ◽  
Context Cues

Past research suggests that heterosexual men show a category-specific pattern of sexual arousal, showing greater arousal to stimuli depicting women than those depicting men.Gender is not, however, the only factor affecting sexual arousal in men. Research has shown that men regard relationship context as an important factor in sexual arousal.Additionally, men show greater sexual arousal to novel than to familiar sexual stimuli. Sociosexuality, the preference for committed or uncommitted sexual relationships,affects behaviour and partner preferences. The current study investigates the relationship between sociosexuality, gender cues, relationship context cues, and sexual arousal in menby assessing 25 heterosexual men’s genital and subjective sexual arousal to 18 audio narratives describing sexual or neutral encounters with female and male strangers,friends, or long-term relationship partners. I expect that heterosexual men will show greater subjective and genital arousal in response to stimuli depicting a sexual encounter with a woman than to stimuli depicting a sexual encounter with a man, replicating previous research. I hypothesize that there will be an interaction between gender cues and relationship context, such that men will show greater sexual arousal to stimuli depicting novel female sexual partners (strangers and friends) than to stimuli depicting familiar female sexual partners (long-term partners). I predict that higher sociosexuality scores, indicating a greater preference for uncommitted sexual relationships, will correlate with greater sexual arousal to uncommitted relationship contexts (strangers or friends), whereas lower sociosexuality scores, will correspond with greater sexual arousal to the committed relationship context (long-term partner).

scholarly journals Attitudes Toward Sexual Behaviors in Long-Term Care: Development of an Assessment Tool

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 602-603
Author(s):  
Rachael Spalding ◽  
Emma Katz ◽  
Barry Edelstein
Keyword(s):  
Sexual Behaviors ◽  
Long Term Care ◽  
Assessment Tool ◽  
Qualitative Interviews ◽  
Family Members ◽  
Community Dwelling ◽  
Term Care ◽  
Care Development

Abstract Most older adults living in long-term care settings (LTCs) indicate that expressing their sexuality is important to them (Doll, 2013). Little is known about the general public’s attitudes towards sexual behaviors in LTCs. Attitudes of LTC residents’ family members are particularly important, as family members are most likely to visit residents and to care about their quality of life. Family members’ attitudes could in turn inform facility policies and management. We will present preliminary data from a series of qualitative interviews with community-dwelling adults regarding their attitudes. We will discuss how these data are being used to inform current work on a measure of attitudes toward sexual behavior in LTCs.

Fertilization dynamics of sperm from different male mating tactics in bluegill (Lepomis macrochirus)

2005 ◽  
Vol 83 (12) ◽  
pp. 1638-1642 ◽  
Author(s):  
Albrecht I Schulte-Hostedde ◽  
Gary Burness
Keyword(s):  
Sperm Competition ◽  
Lepomis Macrochirus ◽  
Fertilization Success ◽  
Male Mating ◽  
Motile Sperm ◽  
Mating Tactics ◽  
Sperm Activation ◽  
Competition Theory ◽  
Sperm Density ◽  
Over Time

Sperm competition results in the evolution of ejaculate characteristics such as high sperm density, high motility, and fast sperm swimming speed. A fundamental assumption of sperm competition theory is that ejaculates with high motility and fast-swimming sperm have an advantage with respect to fertilization success. We tested this assumption by studying the fertilization dynamics of alternative mating tactics (cuckolders and parentals) of male bluegill (Lepomis macrochirus Rafinesque, 1819). Sneakers (cuckolders) have faster swimming sperm and a higher proportion of motile sperm immediately following sperm activation than do parentals; however, these variables decline more quickly over time in sneaker sperm than in the sperm of parental males. We used a controlled fertilization experiment to test the prediction that parental males will have higher fertilization success than sneakers late in the sperm activation cycle because of the reduced rate of decline in ejaculate quality over time. We found that as the time from sperm activation increases parental sperm fertilizes more eggs than the sperm of sneakers. Our results support the idea that fertilization success is higher when ejaculates contain a higher proportion of either motile sperm or faster swimming sperm, all else being equal. In addition, after controlling for time from sperm activation, we found a significant bias in fertilization success toward parental males, suggesting that cryptic female choice might play a role in fertilization dynamics.

The long-term habituation of sexual arousal in human males: A crossover design

1997 ◽  
Vol 47 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Joseph J. Plaud ◽  
George A. Gaither ◽  
Susan Amato Henderson ◽  
Mary K. Devitt
Keyword(s):  
Sexual Arousal ◽  
Crossover Design

scholarly journals Sperm competition games: optimal sperm allocation in response to the size of competing ejaculates

2006 ◽  
Vol 274 (1607) ◽  
pp. 209-217 ◽  
Author(s):  
Leif Engqvist ◽  
Klaus Reinhold
Keyword(s):  
Sperm Competition ◽  
Negative Correlation ◽  
Competitive Ability ◽  
Sperm Storage ◽  
Competition Intensity ◽  
Mating Partner ◽  
Storage Model ◽  
Sperm Allocation ◽  
Competition Theory ◽  
Different Levels

Sperm competition theory predicts that when males are certain of sperm competition, they should decrease sperm investment in matings with an increasing number of competing ejaculates. How males should allocate sperm when competing with differently sized ejaculates, however, has not yet been examined. Here, we report the outcomes of two models assuming variation in males' sperm reserves and males being faced with different amounts of competing sperm. In the first ‘spawning model’, two males compete instantaneously and both are able to assess the sperm competitive ability of each other. In the second ‘sperm storage model’, males are sequentially confronted with situations involving different levels of sperm competition, for instance different amounts of sperm already stored by the female mating partner. In both of the models, we found that optimal sperm allocation will strongly depend on the size of the male's sperm reserve. Males should always invest maximally in competition with other males that are equally strong competitors. That is, for males with small sperm reserves, our model predicts a negative correlation between sperm allocation and sperm competition intensity, whereas for males with large sperm reserves, this correlation is predicted to be positive.

scholarly journals Conceptual developments in sperm competition: a very brief synopsis

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200061 ◽  
Author(s):  
Geoff A. Parker
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Seminal Fluid ◽  
Female Reproduction ◽  
Internal Fertilization ◽  
Seminal Fluid Proteins ◽  
Competition Theory ◽  
Past Half Century ◽  
Mate Acquisition ◽  
Gamete Competition

The past half century has seen the development of the field of post-ejaculatory sexual selection, the sequel to sexual selection for mate-acquisition (pre-ejaculatory) described by Darwin. In richness and diversity of adaptations, post-ejaculatory selection rivals that of pre-ejaculatory sexual selection. Anisogamy—and hence two sexes—likely arose by primeval gamete competition, and sperm competition remains a major force maintaining high sperm numbers. The post-ejaculatory equivalent of male–male competition for matings, sperm competition was an intense ancestral form of sexual selection, typically weakening as mobility and internal fertilization developed in many taxa, when some expenditure became diverted into pre-ejaculatory competition. Sperm competition theory has been relatively successful in explaining variation in relative testes size and sperm numbers per ejaculate and is becoming more successful in explaining variation in sperm phenotype. Sperm competition has generated many other male adaptations such as seminal fluid proteins that variously modify female reproduction towards male interests, and copulatory plugs, prolonged copulations and post-ejaculatory guarding behaviour that reduce female remating probability, many of which result in sexual conflict. This short survey of conceptual developments is intended as a broad overview, mainly as a primer for new researchers. This article is part of the theme issue ‘Fifty years of sperm competition'.

scholarly journals Male crickets adjust ejaculate quality with both risk and intensity of sperm competition

2007 ◽  
Vol 3 (5) ◽  
pp. 520-522 ◽  
Author(s):  
Leigh W Simmons ◽  
Amy Denholm ◽  
Chantelle Jackson ◽  
Esther Levy ◽  
Ewa Madon
Keyword(s):  
Sperm Competition ◽  
High Intensity ◽  
Teleogryllus Oceanicus ◽  
Competition Theory ◽  
Rival Male ◽  
Testes Size ◽  
Increasing Risk ◽  
Live Sperm

Sperm competition theory predicts that males should increase their expenditure on the ejaculate with increasing risk of sperm competition, but decrease their expenditure with increasing intensity. There is accumulating evidence for sperm competition theory, based on examinations of testes size and/or the numbers of sperm ejaculated. However, recent studies suggest that ejaculate quality can also be subject to selection by sperm competition. We used experimental manipulations of the risk and intensity of sperm competition in the cricket, Teleogryllus oceanicus . We found that males produced ejaculates with a greater percentage of live sperm when they had encountered a rival male prior to mating. However, when mating with a female that presented a high intensity of sperm competition, males did not respond to risk, but produced ejaculates with a reduced percentage of live sperm. Our data suggest that males exhibit a fine-tuned hierarchy of responses to these cues of sperm competition.

Disease Prevention and Health Promotion

2018 ◽  
Author(s):  
Peter D Hurd ◽  
Justinne Guyton ◽  
Ardis Hanson
Keyword(s):  
Public Health ◽  
Health Promotion ◽  
Disease Prevention ◽  
Infectious Diseases ◽  
Sexual Behaviors ◽  
Consumer Health ◽  
Prevention And Health Promotion ◽  
Lack Of Exercise ◽  
Long Term Impact

Changing human behavior is challenging; however, having a long-term impact on the improved health of a population is a compelling reason for an increased public health commitment by individuals in pharmacy. Any of the activities that individuals and populations pursue have a direct effect on their health, from drinking clean water to breathing fresh air. Health behaviors mitigate or exacerbate chronic diseases, such as heart disease, cancer, diabetes, and stroke, and human behaviors can affect the resurgence of infectious diseases (and the emergence of new infectious diseases). Other behavioral factors, such as tobacco use, poor diet, lack of exercise, alcohol consumption, at-risk sexual behaviors, and avoidable injuries, contribute prominently to increased morbidity and mortality. This chapter addresses basic public health principles of disease prevention and health promotion, looking at consumer health education, health literacy, social media, and program design and evaluation.

Early Pregnancy Risk Among Adolescents With ADHD: A Nationwide Longitudinal Study

2020 ◽  
pp. 108705471990023
Author(s):  
Mao-Hsiu Hua ◽  
Kai-Lin Huang ◽  
Ju-Wei Hsu ◽  
Ya-Mei Bai ◽  
Tung-Ping Su ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Sexual Behaviors ◽  
Lower Risk ◽  
Medication Use ◽  
Risky Sexual Behaviors ◽  
Adhd Medication ◽  
Pregnancy Risk ◽  
Increased Risk

Objective: ADHD potentially leads to risky sexual behaviors, and is considered a major risk factor for early pregnancy (EP). However, the association between ADHD and subsequent EP remains unknown. Method: Seven thousand five hundred five adolescents with ADHD and 30,020 age- and sex-matched individuals without ADHD were enrolled from 2001 to 2009 and were followed until the end of 2011. Adolescents who developed any pregnancy (at age ≤30 years) or EP (at age <20 years) during the follow-up period were identified. Results: Adolescents with ADHD were found to be prone to pregnancy (hazard ratio [HR] = 1.27) and EP (HR = 2.30) compared with those without ADHD. Long-term ADHD medication use was related to a lower risk of subsequent any pregnancy (HR = 0.72) and EP (HR = 0.69). Conclusion: Adolescents with ADHD had an increased risk of any pregnancy and EP compared with their non-ADHD counterparts. Long-term ADHD medication use was associated with a lower subsequent EP risk.

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