Sexual arousal

sexually arousedarousalaroused
While there is disagreement among neurologists on whether or not it is possible to categorically distinguish male brains and female brains by measuring many variables in the brain, neurologists agree that all single variables in the brain display more individual variation and overlap between the sexes than differences between the sexes. For instance, men and women alike are capable of classifying sex acts as sexual no matter if they find them appealing or not, making a genital response to unappealing erotic stimuli a single mechanism step.

Menstrual cycle

menstrual periodmenstrualmenstruating
Near ovulation, women may have increased physical attraction and interest in attending social gatherings with men. During the fertile phase of the cycle, women appear to prefer males who are more masculine. The intensity of mate guarding differs across the phases of the cycle, with increased mate guarding occurring when women are fertile. During the fertile phase, some women may experience more attraction, fantasies and sexual interest for extra pair men and less for the primary partner. Some women may also engage in extra-pair flirtations and demonstrate a preference for extra pair copulation. Preferences for voice pitch change across the cycle.

Human sexual activity

sexual activitysexual behaviorsex
Sexual activity can be classified in a number of ways: acts which involve one person (also called autoeroticism) such as masturbation, or two or more people such as vaginal sex, anal sex, oral sex or mutual masturbation. Penetrative sex between two people may be described as sexual intercourse, but definitions vary. If there are more than two participants in a sex act, it may be referred to as group sex. Autoerotic sexual activity can involve use of dildos, vibrators, butt plugs, and other sex toys, though these devices can also be used with a partner.

Erection

erectpenile erectionerect penis
Unlike human sexual intercourse, where the male penis commonly becomes erect before entering the female, canine copulation involves the male first penetrating the female, after which swelling of the penis to erection occurs. An elephant's penis is S-shaped when fully erect and has a Y-shaped orifice. Given the small amount of erectile tissue in a bull's penis, there is little enlargement after erection. The penis is quite rigid when non-erect, and becomes even more rigid during erection. Protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure. A male fossa's penis reaches to between his forelegs when erect.

Ovulatory shift hypothesis

In humans, as in all mammals, females are the sex that invests more in parenting, simply through the lengthy and taxing process of pregnancy and lactation, whereas males need only to contribute one act of sexual intercourse to pass on their genes. Thus, females are expected to be the more selective sex, and males are expected to be more competitive. However, unlike many species where males do not contribute to parenting at all, humans have highly dependent offspring, and a complex social structure that allows males to make significant and important investments in parenting effort.

Fertility

fertilemale fertilityfemale fertility
Fertility declines with age in both sexes. In women the decline is more rapid, with complete infertility normally occurring around the age of 50. Pregnancy rates for sexual intercourse are highest when it is done every 1 or 2 days, or every 2 or 3 days. Studies have shown no significant difference between different sex positions and pregnancy rate, as long as it results in ejaculation into the vagina. A woman's menstrual cycle begins, as it has been arbitrarily assigned, with menses. Next is the follicular phase where estrogen levels build as an ovum matures (due to the follicular stimulating hormone, or FSH) within the ovary.

Sexual selection

sexually selectedmale-male competitionintrasexual selection
Why Sex Evolved. "The sexual propaganda theory".

Courtship

courtingsuitorcourt
The process of elimination was significant because now the viewer was able hear their voice, see their face and watch their body language to determine a physical attraction to the candidates. In online dating, individuals create profiles where they disclose personal information, photographs, hobbies, interests, religion and expectations. Then the user can search through hundreds of thousands of accounts and connect with multiple people at once which in return, gives the user more options and more opportunity to find what meets their standards. Online dating has influenced the idea of choice.

Heterosexuality

heterosexualstraightheterosexuals
Heterosexuality is romantic attraction, sexual attraction or sexual behavior between persons of the opposite sex or gender. As a sexual orientation, heterosexuality is "an enduring pattern of emotional, romantic, and/or sexual attractions" to persons of the opposite sex; it "also refers to a person's sense of identity based on those attractions, related behaviors, and membership in a community of others who share those attractions." Someone who is heterosexual is commonly referred to as straight. Along with bisexuality and homosexuality, heterosexuality is one of the three main categories of sexual orientation within the heterosexual–homosexual continuum.

Desire discrepancy

During the first two years of a gay couples relationship, two-thirds of gay couples had sexual intercourse three of more times a week compared to lesbian couples in a two-year relationship. Even so, during a ten-year relationship 11% of gay couples copulated compared to 1% of lesbian couples signifying that gay couples have higher frequencies of sex. Given that males desire higher levels of sex in comparison to females, it is thus, common to find that gay males, in comparison to heterosexuals and lesbians, have the highest frequencies of sex across all stages of their relationships. Thus, this signifies that gay couples encounter in higher levels of sexual intercourse.

Sex Tips from Rock Stars

Copulation. Daring Locations. Dating & Courtship. Divorce. Drugs & Alcohol (& Impotence). Enlargements & Extensions. Fetishes & Fantasies. Foreplay & Arousal. Groupies. Hygiene & Grooming. Kissing & Caressing. Knitting & Crocheting. Marriage. Masturbation (Autoeroticism). Money for Sex. One Night Stands. Oral Sex. Romancing & Winning Hearts. Safe Sex (Contraceptives & STDs). Sexual Preference (Hetero & Homo). Technique Improvements. Toys & Tools. Virginity. Official Sex Tips from Rock Stars website http://www.sextipsfromrockstars.com. Listing on Amazon UK https://www.amazon.co.uk/Sex-Tips-Rock-Stars-Their/dp/1849384045.

Index of human sexuality articles

Philosophy of sex. Phone sex. Physical attractiveness. Physical intimacy. Physiology. Pierre-François Hugues d'Hancarville. Pillow talk. Pinafore eroticism. Piquerism. Plant reproduction. Platonic love. Play piercing. Playboy (lifestyle). Playing doctor. Plietesials. PLUR. Plushophilia. Polyamory. Polyamoury. Polyfidelity. Polymorphous perversity. Polysexuality. Polysexuality (book). Pompoir. POPLINE. Population Council. Porcine zona pellucida. Porn groove. Porn Sunday. Pornographic film actor. Pornography. Pornography addiction. Pornography in Italy. Pornophobia. Pornosonic. Post-coital tristesse. Post-SSRI sexual dysfunction. Post Office (game). Postorgasmic illness syndrome.

Interpersonal attraction

attractionattractedChemistry
Sexual attraction. Socionics. Social connection. Vulnerability and care theory of love.

Aesthetics

aestheticphilosophy of artart theory
Another example is that body symmetry and proportion are important aspects of physical attractiveness which may be due to this indicating good health during body growth. Evolutionary explanations for aesthetical preferences are important parts of evolutionary musicology, Darwinian literary studies, and the study of the evolution of emotion. As well as being applied to art, aesthetics can also be applied to cultural objects, such as crosses or tools.

Sexual stimulation

sexual pleasuresexually stimulatederotic pleasure
., masturbation) or by a sexual partner (sexual intercourse or other sexual activity), by use of objects or tools, or by some combination of these methods. Some people practice orgasm control, whereby a person or their sexual partner controls the level of sexual stimulation to delay orgasm, and to prolong the sexual experience leading up to orgasm. Physical sexual stimulation usually consists of touching the genitals or other erogenous zones. Masturbation, erotic massage, sexual intercourse, a handjob or fingering are types of physical sexual stimulation involving the genitals.

Sex position

double penetrationsexual positionsex positions
A sex position is a position of the body that people use for sexual intercourse or other sexual activities. Sexual acts are generally described by the positions the participants adopt in order to perform those acts. Though sexual intercourse generally involves penetration of the body of one person by another, sex positions commonly involve penetrative or non-penetrative sexual activities. Three categories of sexual intercourse are commonly practiced: vaginal intercourse (involving vaginal penetration), anal penetration, and oral sex (especially mouth-on-genital stimulation).

Pregnancy

pregnantfirst trimesterpregnant women
Sex during pregnancy is a low-risk behavior except when the healthcare provider advises that sexual intercourse be avoided for particular medical reasons. For a healthy pregnant woman, there is no safe or right way to have sex during pregnancy. Pregnancy alters the vaginal flora with a reduction in microscopic species/genus diversity. Regular aerobic exercise during pregnancy appears to improve (or maintain) physical fitness. Physical exercise during pregnancy does appear to decrease the need for C-section. Bed rest, outside of research studies, is not recommended as there is no evidence of benefit and potential harm.

Semen

seminal fluidseminalsperm
Internal fertilization takes place after insemination of a female by a male through copulation. In most vertebrates, including amphibians, reptiles, birds and monotreme mammals, copulation is achieved through the physical mating of the cloaca of the male and female. In marsupial and placental mammals, copulation occurs through the vagina. During the process of ejaculation, sperm passes through the ejaculatory ducts and mixes with fluids from the seminal vesicles, the prostate, and the bulbourethral glands to form the semen. The seminal vesicles produce a yellowish viscous fluid rich in fructose and other substances that makes up about 70% of human semen.

Mating

matematescopulation
Evolution of sex. Lordosis behavior. Mate choice copying. Mating system. Reproduction. Sex determination system. Sexual conflict. Sexual intercourse. Introduction to Animal Reproduction. Advantages of Sexual Reproduction.

Facial symmetry

facial asymmetrysymmetricalEchoism (facial symmetry)
Physical attractiveness. Oral diagnosis 402 by Dr.Gihane Gharib Madkour, Lecturer of Oral Medicine, Oral Diagnosis & Periodontology, Cairo University. Symmetric Shape Deformation Considering Facial Features and Attractiveness Improvement by Kim Jung-Sik, Shin Il-Kyu, Soo-Mi Choi, Dept. of Computer Science and Engineering, Vol.16 No.2 P.29~37 Sejong University. Chunyu L, Changshui Z, Fang W, Pingfan Y. Principle component analysis based symmetry detection. Acta Electronica Sinica 1999;27(5):25–8. Enquist M, Arak A. Symmetry, beauty and evolution.

Flirting

flirtflirtatiousflirtation
Many studies have confirmed that sex is a driving motivation for flirting behaviours. Additionally, Messman and colleagues’ study provided support for this hypothesis; it demonstrated that, the more one was physically attracted to a person, the higher the chances one would flirt with them. Flirting in the goal of signalling interest appears as a puzzling phenomenon when considering that flirting is often performed very subtly. In fact, evidence shows that people are often mistaken in how they interpret flirting behaviours. Thus, if a main purpose of flirting is to signal interest to the other person, why isn't this signalling done more clearly and explicitly?

Sexual desire

desiresexual urgessexual motivation
In addition, the pill reduces the sexual attractiveness of women by changing their estrus phase. Oral contraceptives have been known to increase the levels of sex hormone-binding globulin (SHBG) in the body. In turn, high SHBG levels have been associated with a decline in sexual desire. Though it is not used as medication, the drug methamphetamine has a strong positive effect on many aspects of sexual behaviour, including sexual desire. Sexual desire is said to be influenced by androgens in men and by androgens and estrogens in women. Many studies associate the sex hormone, testosterone with sexual desire. Testosterone is mainly synthesized in the testes in men and in the ovaries in women.

Attractiveness

eye candyattractionallure
Physical attractiveness is the perception of the physical traits of an individual human person as pleasing or beautiful. It can include various implications, such as sexual attractiveness, cuteness, similarity and physique. Judgment of attractiveness of physical traits is partly universal to all human cultures, partly dependent on culture or society or time period, partly biological, and partly subjective and individual. According to a study determining the golden ratio for facial beauty, the most attractive face is one with average distances between facial features, and an average length and width of the face itself. Facial attractiveness, or beauty, can also be determined by symmetry.

Sexual capital

Erotic capitalSexual Market Value
One economic-related definition is based on the human truth capital theory of Gary Becker, and predicts that people invest rationally in exhibiting their sex appeal when they can expect a return on their investments. He defines this as a form of health capital, which is itself a form of individual capital. Another definition, comes from Capital Portfolio Theory, in which Green argues that sexual capital is part of an individual's overall capital portfolio. An individual can transfer their sexual capital to other forms of capital within Capital Portfolio Theory.

Beauty

beautifuldecorativeclassical beauty
The characterization of a person as “beautiful”, whether on an individual basis or by community consensus, is often based on some combination of inner beauty, which includes psychological factors such as personality, intelligence, grace, politeness, charisma, integrity, congruence and elegance, and outer beauty (i.e. physical attractiveness) which includes physical attributes which are valued on an aesthetic basis. Standards of beauty have changed over time, based on changing cultural values. Historically, paintings show a wide range of different standards for beauty.