Is the decreace in fertility of men cause women arent having as many partners? Less sperm competition.
Selection on female remating interval is influenced by male sperm competition strategies and ejaculate characteristics – PubMed
Female remating rate dictates the level of sperm competition in a population, and extensive research has focused on how sperm competition generates selection on male ejaculate allocation. Yet the way ejaculate allocation strategies in turn generate selection on female remating rates, which ultimatel…
Sperm competition and ejaculate economics – PubMed
Sperm competition was identified in 1970 as a pervasive selective force in post-copulatory sexual selection that occurs when the ejaculates of different males compete to fertilise a given set of ova. Since then, sperm competition has been much studied both empirically and theoretically. Because sper…
Sexual selection and sperm diversity in primates – PubMed
Many aspects of primate sperm physiology and reproductive behavior have been influenced by sexual selection, especially in taxa exposed to sperm competition where females mate with multiple partners. Primate sperm diversity reflects therefore the evolutionary divergences of the different primate spe…
Women Like Bick DICK and We Cannot Lie!
Penis size interacts with body shape and height to influence male attractiveness – PubMed
Compelling evidence from many animal taxa indicates that male genitalia are often under postcopulatory sexual selection for characteristics that increase a male’s relative fertilization success. There could, however, also be direct precopulatory female mate choice based on male genital traits. Befor…
Sexual pleasure and motivation – PubMed
Individuals engage in behaviors or partake of specific substances because it pleases them. Indeed, without the sensations of pleasure and displeasure we would be unlikely to repeat or restrict behaviors. Since repetitive sexual activity over the millennia has ensured the continuance of the human rac…
Women can cum as much as men but their minds stop them.
Women’s orgasm – PubMed
An orgasm in the human female is a variable, transient peak sensation of intense pleasure, creating an altered state of consciousness, usually with an initiation accompanied by involuntary, rhythmic contractions of the pelvic striated circumvaginal musculature, often with concomitant uterine and ana…
Linking Sexual Mindfulness to Mixed-Sex Couples’ Relational Flourishing, Sexual Harmony, and Orgasm – PubMed
Marriage is an important adult relationship, and recent research indicates that sexual mindfulness, awareness and non-judgment, may be an important tool in helping maintain relational and sexual well-being. Using a nationally representative U.S. sample of newly married, mixed-sex couples (women’s ag…
The orgasm gap matters for womens happiness in LIFE and her relationship.
The Significance of the Female Orgasm: A Nationally Representative, Dyadic Study of Newlyweds’ Orgasm Experience – PubMed
Wives’ orgasm (wives’ self-report of frequency and husbands’ perception of frequency) has a unique positive association with sexual satisfaction, even after taking into account other aspects of the orgasm experience and sexual communication. Leonhardt ND, Willoughby BJ, Busby DM, et al. The Signific…
Semen displacement as a sperm competition strategy : Multiple mating, self-semen displacement, and timing of in-pair copulations – PubMed
Using a sample of 652 college students, we examined several implications of the hypothesis that the shape of the human penis evolved to enable males to substitute their semen for those of their rivals. The incidence of double mating by females appears sufficient to make semen displacement adaptive (…
Choosy but not chaste: multiple mating in human females – PubMed
When Charles Darwin set out to relate his theory of evolution by natural selection to humans he discovered that a complementary explanation was needed to properly understand the great variation seen in human behavior. The resulting work, The Descent of Man and Selection in Relation to Sex, laid out…
Male-male competition, female mate choice and their interaction: determining total sexual selection – PubMed
Empirical studies of sexual selection typically focus on one of the two mechanisms of sexual selection without integrating these into a description of total sexual selection, or study total sexual selection without quantifying the contributions of all of the mechanisms of sexual selection. However,…