Sexual intercourse

Sexual intercourse
The missionary position of human sexual intercourse depicted by Édouard-Henri Avril

Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction.[1][2] The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails. The term may also describe other sexual penetrative acts, such as anal sex, oral sex and fingering, which can be practiced by both heterosexual and same-sex partners.[2]

Sexual intercourse typically plays a powerful role in human bonding, often being used solely for pleasure and leading to stronger emotional bonds.[3] Non-penetrative sex (for example, non-penetrative cunnilingus) has been referred to as "outercourse",[4][5][6][7] but may also be among the sexual acts contributing to human bonding and considered intercourse. The term sex can be taken to mean any mutual genital stimulation (i.e. all forms of intercourse and "outercourse"),[2][8] and as with most forms of sexual interaction, individuals are at risk for contracting sexually transmitted diseases.[9][10] Thus, safe sex practices are advised.[9]

Religious beliefs often play a role in societal views regarding sexual intercourse, other sexual acts, and their purpose. Some sections of Christianity commonly view sex in marriage as holy and for the purpose of reproduction, while other sections do not. Modern Judaism and Islam view sexual intercourse between husband and wife as a spiritual and edifying action. The limits of marriage and concubinage within these traditions has changed over time, along with corresponding views of acceptable sexual behavior. The teachings of Hinduism and Buddhism on sexuality have differing interpretations. Buddhism's injunction to "refrain from sexual misconduct" finds its interpretation and practical definitions at the level of the individual. However, within each of these major religious traditions exist subgroups with varying stances on acceptable sexual practices, and some religious groups prohibit monks and nuns from engaging in sexual intercourse altogether.

Sexual intercourse between non-human animals is more often referred to as copulation; for most, mating and copulation occurs at the point of estrus (the most fertile period of time in the female's reproductive cycle),[11][12] which increases the chances of successful impregnation. However, bonobos,[13] dolphins,[14] and chimpanzees are known to engage in sexual intercourse even when the female is not in estrus, and to engage in sex acts with same-sex partners.[14][15] Like humans engaging in sex primarily for pleasure,[3] this behavior in the above mentioned animals is also presumed to be for pleasure,[16] and a contributing factor to strengthening their social bonds.[3]

Contents

Practice

Bonding and affection

In animals, sexual intercourse ranges from a purely reproductive activity to one of emotional bonding between mated pairs. It typically plays a powerful role in human bonding. In many societies, for example, it is normal for couples to have frequent intercourse while using birth control, sharing pleasure and strengthening their emotional bond through sex even though they are deliberately avoiding pregnancy.[3]

In humans and bonobos, the female undergoes relatively concealed ovulation so that both male and female partners commonly do not know whether she is fertile at any given moment. One possible reason for this distinct biological feature may be formation of strong emotional bonds between sexual partners important for social interactions and, in the case of humans, long-term partnership rather than immediate sexual reproduction.[3]

Humans, bonobos, dolphins, and chimpanzees are all intelligent social animals, whose cooperative behavior proves far more successful than that of any individual alone. In these animals, the use of sex has evolved beyond reproduction, to apparently serve additional social functions.[13][14][15] Sex reinforces intimate social bonds between individuals to form larger social structures. The resulting cooperation encourages collective tasks that promote the survival of each member of the group.[3]

The concept of love belongs to the domain of the virtues and to higher cognitive function, and is thus generally reserved for humans. When applied to animals, "love" is used largely for its colloquial meaning. In certain contexts, such as scientific research into emotional bonding, "love" is given a neuroscientific or neurochemical definition (rather than a human or a virtuous definition), and in such contexts human and animal intercourse are considered equivalent.

Reproduction and sexual practices

Vaginal sexual intercourse, also called coitus, is the human form of copulation. While its natural purpose and result is reproduction, it is often performed entirely for pleasure and/or as an expression of love and emotional intimacy.[2][3] Coitus is the basic reproductive method of humans, and may be preceded by foreplay, which leads to sexual arousal of the partners, resulting in the erection of the penis and natural lubrication of the vagina. To engage in coitus, the erect penis is inserted into the vagina and one or both of the partners move their hips to move the penis backward and forward inside the vagina to cause friction, typically without fully removing the penis. In this way, they stimulate themselves and each other, often continuing until orgasm in either or both partners is achieved. For females, stimulation of the clitoris plays a significant role in sexual intercourse; most achieve orgasm only through clitoral stimulation.[17][18][19][20]

Penetration by the hardened, erect penis is additionally known as intromission, or by the Latin name immissio penis (Latin for "insertion of the penis"). During ejaculation, which usually accompanies male orgasm, a series of muscular contractions delivers semen containing male gametes known as sperm cells or spermatozoa from the penis into the vagina. The subsequent route of the sperm from the vault of the vagina is through the cervix and into the uterus, and then into the fallopian tubes. Millions of sperm are present in each ejaculation, to increase the chances of one fertilizing an egg or ovum (see sperm competition). When a fertile ovum from the female is present in the fallopian tubes, the male gamete joins with the ovum, resulting in fertilization and the formation of a new embryo. When a fertilized ovum reaches the uterus, it becomes implanted in the lining of the uterus, known as endometrium, and a pregnancy begins. Unlike most species, human sexual activity is not linked to periods of estrus and can take place at any time during the reproductive cycle, even during pregnancy.[21] Where a sperm donor has sexual intercourse with a woman who is not his partner, for the sole purpose of impregnating the woman, this practice may be known as natural insemination, or NI.[22]

Roughly six million U.S. women become pregnant per year. About two-thirds of these pregnancies result in live births and roughly 25% in abortions; the remainder end in miscarriage.[23] The U.S. teenage pregnancy rate fell by 27 percent between 1990 and 2000, from 116.3 pregnancies per 1,000 girls aged 15–19 to 84.5. This data includes live births, abortions, and fetal losses. Almost 1 million American teenage women, 10% of all women aged 15–19 and 19% of those who have had intercourse, become pregnant each year,[24] while Britain has been stated to have a teenage pregnancy rate similar to America's.[25]

Reproduction methods and pregnancy also extend to gay and lesbian couples. For gay male pairings, there is the option of surrogate pregnancy; for lesbian couples, there is donor insemination in addition to choosing surrogate pregnancy.[26][27] Further, developmental biologists have been researching and developing techniques to facilitate biological same-sex reproduction, though this has yet to be demonstrated in humans (see same-sex reproduction).[28][29] Surrogacy and donor insemination remain the primary methods. Surrogacy is an arrangement in which a woman carries and delivers a child for another couple or person. The woman may be the child's genetic mother (traditional surrogacy) or she may carry a pregnancy to delivery after having another woman's eggs transferred to her uterus (gestational surrogacy). Gay and lesbian pairings who want the host to have no genetic connection to the child may choose gestational surrogacy and enter into a contract with an egg donor. Gay male couples might decide that they should both contribute semen for the in vitro fertilisation (IVF) process, which further establishes the couple's joint intention to become parents.[27] Lesbian couples often have contracts drafted to extinguish the legal rights of the sperm donor, while creating legal rights for the parent who is not biologically related to the child.[30]

In addition to vaginal intercourse, sexual intercourse can encompass other forms of insertive sexual behavior, such as oral sex and anal intercourse. Sexual acts, other than as a means of reproduction, are varied: Oral sex consists of all the sexual activities that involve the use of the mouth, tongue, and possibly throat to stimulate genitalia. It is sometimes performed to the exclusion of all other forms of sexual activity, and may include the ingestion or absorption of semen or vaginal fluids. While there are many sexual acts involving the anus, anal cavity, sphincter valve and/or rectum, the most common meaning of anal sex is the insertion of a man's penis into another person's rectum.[31][32]

Non-penetrative sex acts are also common. These acts are sometimes seen among heterosexuals as maintaining "technical virginity."[33][34][35][36] Some gay men view frotting and oral sex as maintaining their virginity,[37] while others consider the acts to be their main form of intercourse.[38][39][40][41][42] The phrase "to have sex" can mean any or all of these behaviors (intercourse and outercourse), and there are a number of sex positions.

Prevalence, safe sex, and contraception

By their late teenage years, at least 3/4 of all men and women have had intercourse, and more than 2/3 of all sexually experienced teens have had 2 or more partners.[43] Among sexually active 15- to 19-year-olds in the U.S., 83% of females and 91% of males reported using at least one method of birth control during last intercourse.[44]

There are a variety of safe sex practices, including non-penetrative sex acts, and heterosexual couples may use oral or anal sex (or both) as a means of contraception.[33][34][35] In 2004, the Guttmacher Institute indicated in 2002 that 62% of the 62 million women aged 15–44 are currently using a contraceptive method, that among U.S. women who practice contraception, the Pill is the most popular choice (30.6%), followed by tubal sterilization (27.0%) and the male condom (18.0%), and that 27% of teenage women using contraceptives choose condoms as their primary method.[45]

In 2006, a survey conducted by The Observer showed that most adolescents in Britain were waiting longer to have sexual intercourse than they were only a few years earlier. In 2002, 32% of British teenagers were having sex before the age of 16; in 2006, it was only 20%. The average age a teen lost his/her virginity was 17.13 years in 2002; in 2006, it was 17.44 years on average for girls and 18.06 for boys. The most notable drop among teens who reported having sex was 14- and 15-year-olds.[46] A 2008 survey conducted by YouGov for Channel 4 showed that 40% of all 14- to 17-year-olds are sexually active, 74% of sexually active 14- to 17-year-olds have had a sexual experience, and 6% of teens would wait until marriage before having sex.[47] Sexually transmitted infections are also on the increase in Britain.[25] One in nine sexually active teens has chlamydia and 790,000 teens have sexually transmitted infections. In 2006, The Independent newspaper reported that the biggest rise in sexually transmitted infections was in syphilis, which rose by more than 20%, while increases were also seen in cases of genital warts and herpes.[48]

The National Survey of Sexual Health and Behavior (NSSHB) indicated in 2010 that 1 of 4 acts of vaginal intercourse are condom protected in the U.S. (1 in 3 among singles), condom use is higher among black and Hispanic Americans than among white Americans and those from other racial groups, and adults using a condom for intercourse were just as likely to rate the sexual extent positively in terms of arousal, pleasure and orgasm than when having intercourse without one.[49]

Duration

Intercourse often ends when the man has ejaculated. Thus the partner might not have time to reach orgasm. In addition, many men suffer from premature ejaculation. Conversely, many women require a substantially longer duration of stimulation than men before reaching an orgasm.[50]

A survey of Canadian and American sex therapists said that the average time for intromission was 7 minutes and that 1 to 2 minutes was too short, 3 to 7 minutes was adequate and 7 to 13 minutes desirable,[51] while 10 to 30 minutes was too long.[52][53]

Coitus difficulties

Anorgasmia is regular difficulty reaching orgasm after ample sexual stimulation, causing personal distress. This is much more common in women than men. The physical structure of the act of coitus favors penile stimulation over clitoral stimulation. The location of the clitoris then often necessitates manual stimulation in order for the female to achieve orgasm. About 15 percent of women report difficulties with orgasm, and as many as 10 percent of women in the United States have never climaxed. Even women who orgasm on a regular basis only climax about 50 to 70 percent of the time.[19][54][55]

Vaginismus is involuntary tensing of the pelvic floor musculature, making coitus distressing, painful, and sometimes impossible for women.[56][57][58] It is a conditioned reflex of the pubococcygeus muscle, sometimes referred to as the "PC muscle". Vaginismus can be a vicious cycle for women, they expect to experience pain during intercourse, which then causes a muscle spasm, which leads to painful intercourse. Treatment of vaginismus often includes both psychological and behavioral techniques, including the use of vaginal dilators. A new medical treatment using Botox is in the testing phase.[58][59] Some women also experience dyspareunia, a medical term for painful or uncomfortable intercourse, of unknown cause.[60][61]

About 40% of males suffer from some form of erectile dysfunction (ED) or impotence, at least occasionally.[62] For those whose impotence is caused by medical conditions, prescription drugs such as Viagra, Cialis, and Levitra are available. However, doctors caution against the unnecessary use of these drugs because they are accompanied by serious risks such as increased chance of heart attack. Moreover, using a drug to counteract the symptom—impotence—can mask the underlying problem causing the impotence and does not resolve it. A serious medical condition might be aggravated if left untreated.[63]

A more common sexual disorder in males is premature ejaculation (PE). The American Urological Association (AUA) estimates that premature ejaculation could affect 21 percent of men in the United States.[64] The U.S. Food and Drug Administration is examining the drug dapoxetine to treat premature ejaculation. In clinical trials, those with PE who took dapoxetine experienced intercourse three to four times longer before orgasm than without the drug. Another ejaculation-related disorder is delayed ejaculation, which can be caused as an unwanted side effect of antidepressant medications such as Fluvoxamine.[65][66]

Although disability-related pain and mobility impairment can hamper intercourse, in many cases the most significant impediments to intercourse for individuals with a disability are psychological.[67] In particular, people who have a disability can find intercourse daunting due to issues involving their self-concept as a sexual being,[68][69] or partner's discomfort or perceived discomfort.[67]

Temporary difficulties can arise with alcohol and sex as alcohol initially increases interest (through disinhibition) but decreases capacity with greater intake.[70]

Health effects

Benefits

In humans, sex has been claimed to produce health benefits as varied as improved sense of smell,[71] stress and blood pressure reduction,[72][73] increased immunity,[74] and decreased risk of prostate cancer.[75][76][77] Sexual intimacy, as well as orgasms, increases levels of the hormone oxytocin, also known as "the love hormone", which helps people bond and build trust.[78][79][80] A long-term study of 3,500 people between 30 and 101 by clinical neuropsychologist David Weeks, MD, head of old age psychology at the Royal Edinburgh Hospital in Scotland, found that "sex helps you look between four and seven years younger", according to impartial ratings of the subjects' photos. Exclusive causation, however, is unclear, and the benefits may be indirectly related to sex and directly related to significant reductions in stress, greater contentment, and better sleep that sex promotes.[81][82][83]

Risks

In contrast to its benefits, sexual intercourse can also be a disease vector.[84] There are 19 million new cases of sexually transmitted diseases (STD) every year in the U.S.,[10] and worldwide there are over 340 million STDs a year.[85] More than half of all STDs occur in adolescents and young adults aged 15–24 years.[86] At least one in four U.S. teenage girls has a sexually transmitted disease.[10][87] In the US, about 30% of 15–17 year old adolescents have had sexual intercourse, but only about 80% of 15–19 year old adolescents report using condoms for their first sexual intercourse.[88] More than 75% of young women age 18–25 years felt they were at low risk of acquiring an STD in one study.[89] Some sexually transmitted infections include:

  • Chlamydia is particularly dangerous because there are many infected individuals who experience no symptoms.[90] Left untreated, chlamydia can lead to many complications, especially for women (such as the inability to bear children later in life).[91]
  • Hepatitis B can also be transmitted through sexual contact.[92] The disease is most common in China and other parts of Asia where 8–10% of the adult population is infected with Hepatitis.[93] About a third of the world's population, more than 2 billion people, have been infected with the hepatitis B virus.[93]
  • Syphilis infection is on the rise in all parts of the United States and is related to about 21% of fetal and newborn deaths in sub-Saharan Africa.[94][95] Syphilis causes genital sores that make it easier to transmit and contract HIV.[95]
  • AIDS is caused by HIV which is spread primarily via sexual intercourse.[96] The World Health Organization reported that in 2008, approximately 33.4 million people had HIV (about 2/3 in sub-Saharan Africa and 1.1 million in the United States[97]) , and 2 million died of AIDS worldwide.[96]

Safe sex is a relevant harm reduction philosophy.[9][98] Condoms and dental dams are widely recommended for the prevention of STDs. According to reports by the National Institutes of Health (NIH) and World Health Organization (WHO), correct and consistent use of latex condoms reduces the risk of HIV/AIDS transmission by approximately 85%–99% relative to risk when unprotected.[99][100]

People, especially those who get little or no physical exercise, have a slightly increased risk of triggering heart attack or sudden cardiac death when they engage in sexual intercourse, or any other vigorous physical exercise which is engaged in on a sporadic basis. Increased risk is temporary with incidents occurring within a few hours of the activity. Regular exercise reduces but does not eliminate the increased risk.[101]

Social effects

Adults

Alex Comfort and others posit three potential advantages of intercourse in humans, which are not mutually exclusive: reproductive, relational, and recreational.[3][102] While the development of the Pill and other highly effective forms of contraception in the mid- and late 20th century increased people's ability to segregate these three functions, they still overlap a great deal and in complex patterns. For example: A fertile couple may have intercourse while contracepting not only to experience sexual pleasure (recreational), but also as a means of emotional intimacy (relational), thus deepening their bonding, making their relationship more stable and more capable of sustaining children in the future (deferred reproductive). This same couple may emphasize different aspects of intercourse on different occasions, being playful during one episode of intercourse (recreational), experiencing deep emotional connection on another occasion (relational), and later, after discontinuing contraception, seeking to achieve pregnancy (reproductive, or more likely reproductive and relational).[102]

Nearly all Americans marry during their lifetime; yet close to half of all first marriages are expected to end in separation or divorce, many within a few years,[103] and subsequent marriages are even more likely to end.[104] Sexual dissatisfaction is associated with increased risk of divorce and relationship dissolution.[104]

According to the National Survey of Sexual Health and Behavior (NSSHB), in 2010, men whose most recent sexual encounter was with a relationship partner reported greater arousal, greater pleasure, fewer problems with erectile function, orgasm, and less pain during the event than men whose last sexual encounter was with a non-relationship partner.[49] According to the Journal of Counseling & Development, many women express that their most satisfying sexual experiences entail being connected to someone, rather than solely basing satisfaction on orgasm.[105]

Adolescents

With regard to adolescent sexuality, sexual intercourse is also often for relational and recreational purposes. However, teenage pregnancy is usually disparaged, and research suggests that the earlier onset of puberty for children puts pressure on children and teenagers to act like adults before they are emotionally or cognitively ready,[106][107] and thus are at risk to suffer from emotional distress as a result of their sexual activities.[107][108][109][110][111] Some studies have found that engaging in sex leaves adolescents, and especially girls, with higher levels of stress and depression.[112] A majority of adolescents in the United States have been provided with some information regarding sexuality,[113] though there have been efforts among social conservatives in the United States government to limit sex education in public schools to abstinence-only sex education curricula.[114]

One group of Canadian researchers found a relationship between self esteem and sexual activity. They found that students, especially girls, who were verbally abused by teachers or rejected by their peers were more likely than other students to engage in sex by the end of the Grade 7. The researchers speculate that low self esteem increases the likelihood of sexual activity: "low self-esteem seemed to explain the link between peer rejection and early sex. Girls with a poor self-image may see sex as a way to become 'popular', according to the researchers".[115]

In India, there is growing evidence that adolescents are becoming more sexually active outside of marriage, which is feared to lead to an increase in the spread of HIV/AIDS among adolescents, as well as the number of unwanted pregnancies and abortions, and add to the conflict between contemporary social values. In India, adolescents have relatively poor access to health care and education, and with cultural norms opposing extramarital sexual behavior, "these implications may acquire threatening dimensions for the society and the nation".[116]

Not all views on adolescent sexual behavior are negative, however. Psychiatrist Lynn Ponton writes, "All adolescents have sex lives, whether they are sexually active with others, with themselves, or seemingly not at all," and that viewing adolescent sexuality as a potentially positive experience, rather than as something inherently dangerous, may help young people develop healthier patterns and make more positive choices regarding sex.[106]

Ethical, moral, and legal issues

Erotic painting from India, 18th century
Erotic painting on ancient Greek kylix

While sexual intercourse is the natural mode of reproduction for the human species, humans also have intricate moral and ethical guidelines which regulate the practice of sexual intercourse and that vary according to religious and governmental laws. Some governments and religions also have strict designations of "appropriate" and "inappropriate" sexual behavior, which include restrictions on the types of sex acts which are permissible. (A historically prohibited and/or regulated sex act is anal sex.)[117][118]

Consent and sexual offenses

Sexual intercourse with a person against their will, or without their informed legal consent, is referred to as rape, and is considered a serious crime in most countries.[119] More than 90% of rape victims are female, 99% of rapists male, and only about 5% of rapists are strangers to the victims.[120]

Most 'developed' countries have age of consent laws specifying the minimum legal age a person may engage in sexual intercourse with substantially older persons, usually set at about 16–18, while the legal age of consent ranges from 12–20 years of age or is not a matter of law in other countries.[121] Sex with a person under the age of consent, regardless of their stated consent, is often considered to be sexual assault or statutory rape depending on differences in ages of the participants.

Some countries codify rape as any sex with a person of diminished or insufficient mental capacity to give consent, regardless of age.[122]

The expression "sexual intercourse" has been used as a term of art in England and Wales and New York State. In England and Wales, from its enactment to its repeal on the 1 May 2004,[123] section 44 of the Sexual Offences Act 1956 read:

Where, on the trial of any offence under this Act, it is necessary to prove sexual intercourse (whether natural or unnatural), it shall not be necessary to prove the completion of the intercourse by the emission of seed, but the intercourse shall be deemed complete upon proof of penetration only.
Unnatural

This expression referred to buggery (including both buggery with a person and buggery with an animal).[124]

Penetration

According to cases decided on the meaning of the statutory definition of carnal knowledge under the Offences against the Person Act 1828, which was in identical terms to this definition, the slightest penetration was sufficient.[125] The book "Archbold" said that it "submitted" that this continued to be the law under the new enactment.[126]

Continuing act

See Kaitamaki v R [1985] AC 147, [1984] 3 WLR 137, [1984] 2 All ER 435, 79 Cr App R 251, [1984] Crim LR 564, PC (decided under equivalent legislation in New Zealand).

Section 7(2) of the Sexual Offences (Amendment) Act 1976 contained the following words: "In this Act . . . references to sexual intercourse shall be construed in accordance with section 44 of the Sexual Offences Act 1956 so far as it relates to natural intercourse (under which such intercourse is deemed complete on proof of penetration only)". The Act made provision, in relation to rape and related offences, for England and Wales, and for courts-martial elsewhere.

From 3 November 1994 to 1 May 2004, section 1(2)(a) of the Sexual Offences Act 1956 (as substituted by section 142 of the Criminal Justice and Public Order Act 1994) referred to "sexual intercourse with a person (whether vaginal or anal)". This section created the offence of rape in England and Wales.

The penal code in New York State provides: § 130.00 Sex offenses; definitions of terms: 1. "Sexual intercourse" has its ordinary meaning and occurs upon any penetration, however slight.[127]

Sexual orientation and gender

There is considerable legal variability regarding definitions of and the legality of sexual intercourse between persons of the same sex and/or gender. For example, in 2003 the New Hampshire Supreme Court ruled that female same-sex relations did not constitute sexual intercourse, based on a 1961 definition from Webster's Third New International Dictionary, in Blanchflower v. Blanchflower, and thereby an accused wife in a divorce case was found not guilty of adultery based on this technicality. Some countries, such as Islamic countries, consider homosexual behavior to be an offense punishable by imprisonment or execution.[128]

Marital status and relationships

Sexual intercourse has traditionally been considered an essential part of a marriage; many religious customs required consummation of the marriage by sexual intercourse, and the failure for any reason to consummate the marriage was a ground for annulment, which did not require a divorce process. Annulment declaration implied that the marriage was void from the start – i.e. there was in law no marriage. Furthermore, continuing sexual relations between the marriage partners is commonly considered a 'marital right' by many religions, permissible to married couples, generally for the purpose of reproduction. Today, there is wide variation in the opinions and teachings about sexual intercourse relative to marriage and other intimate relationships by the world's religions. Examples:

  • Some sections of Christianity, such as Catholicism, commonly view sex in marriage as holy and for the purpose of reproduction.[129][130]
  • Islam views sex within marriage as something pleasurable, a spiritual activity, and a duty.[130][131][132]
  • In Judaism, a married Jewish man is required to provide his wife with sexual pleasure called onah (literally, "her time"), which is one of the conditions he takes upon himself as part of the Jewish marriage contract, ketubah, that he gives her during the Jewish wedding ceremony. In Jewish views on marriage, sexual desire is not evil, but must be satisfied in the proper time, place and manner.[133]
  • In Shi'ia Islam, men are allowed to enter into an unlimited number of temporary marriages, which are contracted to last for a period of minutes to multiple years and permit sexual intercourse. Shi'ia women are allowed to enter only one marriage at a time, whether temporary or permanent.
  • Wiccans believe that, as declared within the Charge of the Goddess, to “Let my [the Goddess] worship be within the heart that rejoiceth; for behold, all acts of love and pleasure are my rituals.” This statement appears to allow one freedom to explore sensuality and pleasure, and mixed with the final maxim within the Wiccan Rede — “26. Eight words the Wiccan Rede fulfill – an’ it harm none, do what ye will.[134] — Wiccans are encouraged to be responsible with their sexual encounters, in whatever variety they may occur.[135]
  • Hinduism has varied views about sexuality, but Hindu society, in general, perceives extramarital sex to be immoral and shameful.[130]
  • Buddhist ethics, in its most common formulation, holds that one should neither be attached to nor crave sensual pleasure.
  • In the Bahá'í Faith, sexual relationships are permitted only between a husband and wife.[136]
  • Unitarian Universalists, with an emphasis on strong interpersonal ethics, do not place boundaries on the occurrence of sexual intercourse among consenting adults.[137]
  • According to the Brahma Kumaris and Prajapita Brahma Kumaris religion, the power of lust is the root of all evil and worse than murder.[138] Purity (celibacy) is promoted for peace and to prepare for life in forthcoming Heaven on earth for 2,500 years when children will be created by the power of the mind.[139][140]
  • Shakers believe that sexual intercourse is the root of all sin and that all people should therefore be celibate, including married couples. Predictably, the original Shaker community that peaked at 6,000 full members in 1840 dwindled to three members by 2009.[141]
  • Meher Baba maintained that "In the beginning of married life the partners are drawn to each other by lust as well as love; but with conscious and deliberate cooperation they can gradually lessen the element of lust and increase the element of love. Through this process of sublimation, lust ultimately gives place to deep love."[142]

In some cases, the sexual intercourse between two people is seen as counter to religious law or doctrine. In many religious communities, including the Catholic Church and Mahayana Buddhists, religious leaders are expected to refrain from sexual intercourse in order to devote their full attention, energy, and loyalty to their religious duties.[143]

Opposition to same-sex marriage is largely based on the belief that sexual intercourse and sexual orientation should be of a heterosexual nature.[144][145][146][147][148][149] The recognition of such marriages is a civil rights, political, social, moral, and religious issue in many nations, and the conflicts arise over whether same-sex couples should be allowed to enter into marriage, be required to use a different status (such as a civil union, which either grant equal rights as marriage or limited rights in comparison to marriage), or not have any such rights. A related issue is whether the term marriage should be applied.[150][151][152]

In other animals

A pair of lions copulating in the Maasai Mara, Kenya
Mating houseflies

In zoology, copulation is often termed as the process in which a male introduces sperm into the female's body. Spiders have separate male and female sexes. Before mating and copulation, a male spins a small web and ejaculates on to it. He then stores the sperm in reservoirs on his large pedipalps, from which he transfers sperm to the female's genitals. Females can store sperm indefinitely.[153]

Many animals which live in the water use external fertilization, whereas internal fertilization may have developed from a need to maintain gametes in a liquid medium in the Late Ordovician epoch. Internal fertilization with many vertebrates (such as reptiles, some fish, and most birds) occur via cloacal copulation (see also hemipenis), while mammals copulate vaginally, and many basal vertebrates reproduce sexually with external fertilization.

However, some terrestrial arthropods do use external fertilization. For primitive insects, the male deposits spermatozoa on the substrate, sometimes stored within a special structure, and courtship involves inducing the female to take up the sperm package into her genital opening; there is no actual copulation. In groups such as dragonflies and spiders, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female (in dragonflies, it is a set of modified sternites on the second abdominal segment; in spiders, it is the male pedipalps). In advanced groups of insects, the male uses its aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a "spermatophore") into the female's reproductive tract.

Humans, bonobos,[13] chimpanzees and dolphins[14] are species known to engage in heterosexual behaviors even when the female is not in estrus, which is a point in her reproductive cycle suitable for successful impregnation. These species, and others, are also known to engage in homosexual behaviors.[15] Humans, bonobos and dolphins are all intelligent social animals, whose cooperative behavior proves far more successful than that of any individual alone. In these animals, the use of sex has evolved beyond reproduction, to apparently serve additional social functions. Sex reinforces intimate social bonds between individuals to form larger social structures. The resulting cooperation encourages collective tasks that promote the survival of each member of the group.[3]

See also

References

  1. ^ Sexual intercourse Encyclopædia Britannica entry.
  2. ^ a b c d "Sexual Intercourse". health.discovery.com. Archived from the original on 2008-08-22. http://web.archive.org/web/20080822040701/http://health.discovery.com/centers/sex/sexpedia/intercourse.html. Retrieved 2008-01-12. 
  3. ^ a b c d e f g h i Diamond, Jared (1992). The rise and fall of the third chimpanzee. Vintage. ISBN 978-0099913801. 
  4. ^ Kate Havelin (1999). Dating: "What Is a Healthy Relationship?". Capstone Press. p. 64. ISBN 0736802924. http://books.google.com/?id=WY-bOwg9m3UC&pg=PA35&dq=Outercourse. 
  5. ^ Isadora Alman (2001). Doing It: Real People Having Really Good Sex. Conari. p. 280. ISBN 1573245208. http://books.google.com/?id=7O6-0j1whq4C&pg=PA97&dq=Outercourse. 
  6. ^ Ann van Sevenant (2005). Sexual Outercourse: A Philosophy of Lovemaking. Peeters. p. 249. ISBN 9042916176. 
  7. ^ Ian Kerner (2004). She Comes First: The Thinking Man's Guide to Pleasuring a Woman. HarperCollins. p. 240. ISBN 1573245208. http://books.google.com/?id=aDwVuI7HAusC&pg=PA5-IA3&dq=Outercourse+is+not+sexual+intercourse. 
  8. ^ Klein, Marty. "The Meaning of Sex". Electronic Journal of Human Sexuality, Volume 1 August 10, 1998:. http://www.ejhs.org/volume1/mklein.htm. Retrieved 2007-12-09. 
  9. ^ a b c World Health Organization, Department of Reproductive Health and Research Global strategy for the prevention and control of sexually transmitted infections: 2006 – 2015. Breaking the chain of transmission, 2007, ISBN 9789241563475
  10. ^ a b c Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance, 2008. Atlanta, GA: U.S. Department of Health and Human Services; November 2009.Fact Sheet
  11. ^ "Females of almost all species except man will mate only during their fertile period, which is known as estrus, or heat..." Helena Curtis (1975). Biology. Worth Publishers. p. 1065. ISBN 0879010401. 
  12. ^ Pineda, Leslie Ernest McDonald (2003). McDonald's Veterinary Endocrinology and Reproduction. Blackwell Publishing. p. 597. ISBN 0813811066. http://books.google.com/?id=vyxgGoDeyj8C&pg=PA307&lpg=PA307&dq=for+most+species+mating+only+occurs+during+fertility+periods. 
  13. ^ a b c Frans de Waal, "Bonobo Sex and Society", Scientific American (March 1995): 82–86.
  14. ^ a b c d Bailey NW, Zuk M (August 2009). "Same-sex sexual behavior and evolution". Trends Ecol. Evol. (Amst.) 24 (8): 439–46. doi:10.1016/j.tree.2009.03.014. PMID 19539396. 
  15. ^ a b c Bruce Bagemihl, Biological Exuberance: Animal Homosexuality and Natural Diversity (St. Martin's Press, 1999). ISBN 0-312-19239-8
  16. ^ Balcombe, J. Pleasurable Kingdom: Animals and the Nature of Feeling Good. Macmillan, New York, 2007. 360 pp. ISBN 1403986029 [1]
  17. ^ O'Connell HE, Sanjeevan KV, Hutson JM (October 2005). "Anatomy of the clitoris". The Journal of Urology 174 (4 Pt 1): 1189–95. doi:10.1097/01.ju.0000173639.38898.cd. PMID 16145367. Lay summary – BBC News (11 June 2006). 
  18. ^ "'I Want a Better Orgasm!'". WebMD. http://web.archive.org/web/20090113132443/http://www.webmd.com/sex/want-better-orgasms. Retrieved August 18, 2011. 
  19. ^ a b Frank JE, Mistretta P, Will J (March 2008). "Diagnosis and treatment of female sexual dysfunction". American family physician 77 (5): 635–42. PMID 18350761. 
  20. ^ Birch, Robert (2007-11-16). "Did you orgasm?". Sexualhealth.com. http://www.sexualhealth.com/article/read/women-sexual-health/orgasm/486/. Retrieved 2010-04-21. 
  21. ^ Diamond, Jared (1997). Why Is Sex Fun?. Basic Books. ISBN 0-465-03127-7. 
  22. ^ Ozolins, John. "Surrogacy: Exploitation or Violation of Intimacy?". Boston University. http://www.bu.edu/wcp/Papers/OApp/OAppOzol.htm. Retrieved 13 July 2010. "This concern for the unity of the spouses seems to be why artificial insemination of a surrogate in cases where the wife cannot supply a fertile ovum is preferred, rather than natural insemination, since it does not involve any relationship with the surrogate" 
  23. ^ "Get "In the Know": 20 Questions About Pregnancy, Contraception and Abortion.". Guttmacher Institute. 2005. http://replay.waybackmachine.org/20091230042018/http://www.guttmacher.org/in-the-know/index.html. Retrieved March 4, 2011. 
  24. ^ Ventura, SJ, Abma, JC, Mosher, WD, & Henshaw, S. (2007-11-16). "Estimated pregnancy rates for the United States, 1990-2000: An Update. National Vital Statistics Reports, 52 (23)". cdc.gov. http://www.cdc.gov/nchs/data/nvsr/nvsr52/nvsr52_23.pdf. Retrieved March 4, 2011. 
  25. ^ a b Christine Webber, psychotherapist and Dr David Delvin. "Talking to pre-adolescent children about sex". Broaching the subject. Net Doctor. http://www.netdoctor.co.uk/sex_relationships/facts/childrenandsex.htm. Retrieved August 5, 2011. 
  26. ^ Berkowitz, D & Marsiglio, W (2007). Gay Men: Negotiating Procreative, Father, and Family Identities. Journal of Marriage and Family 69 (May 2007): 366–381
  27. ^ a b Joan M. Burda (2008). Gay, lesbian, and transgender clients: a lawyer's guide. American Bar Association. p. 437. ISBN 1590319443, 9781590319444. http://books.google.com/?id=QdzB1f8Y8Q8C&pg=PA69&dq=Gay+male+surrogacy#v=onepage&q=Gay%20male%20surrogacy&f=false. Retrieved July 28, 2011. 
  28. ^ Tagami T, Matsubara Y, Hanada H, Naito M. (June 1997). "Differentiation of female chicken primordial germ cells into spermatozoa in male gonads". Dev. Growth Differ. 39 (3): 267–71. doi:10.1046/j.1440-169X.1997.t01-2-00002.x. PMID 9227893. 
  29. ^ "Japanese scientists produce mice without using sperm". Washington Post (Sarasota Herald-Tribune). April 22, 2004. http://news.google.com/newspapers?id=nUIgAAAAIBAJ&sjid=wYQEAAAAIBAJ&pg=6950,1352704&dq=japanese+scientists+combine+two+mouse+eggs+to+produce+daughter+mice&hl=en. Retrieved July 28, 2011. 
  30. ^ Elizabeth Bernstein, Laurie Schaffner (2005). Regulating sex: the politics of intimacy and identity. Perspectives on gender. Psychology Press. p. 313. ISBN 041594869X, 9780415948692. http://books.google.com/?id=OKK09r-u2v0C&pg=PA22&dq=Same+sex+reproduction+methods#v=onepage&q&f=false. Retrieved July 28, 2011. 
  31. ^ Dr. John Dean and Dr. David Delvin. "Anal sex". Netdoctor.co.uk. http://www.netdoctor.co.uk/sexandrelationships/analsex.htm. Retrieved April 29, 2010. 
  32. ^ "Anal Sex". Health.discovery.com. http://health.discovery.com/centers/sex/sexpedia/analsex.html. Retrieved 2011-02-15. 
  33. ^ a b Frederick C. Wood (1968, Digitized July 23, 2008). Sex and the new morality. Association Press, 1968/Original from the University of Michigan. pp. 157 pages. http://books.google.com/?id=sIpqAAAAMAAJ&q=Technical+virginity&dq=Technical+virginity. 
  34. ^ a b Friedman, Mindy (September 20, 2005). "Sex on Tuesday: Virginity: A Fluid Issue". The Daily Californian. http://web.archive.org/web/20090506021934/http://www.dailycal.org/article/19565/sex_on_tuesday_virginity_a_fluid_issue. Retrieved August 23, 2011. 
  35. ^ a b Mark Regnerus (2007). "The Technical Virginity Debate: Is Oral Sex Really Sex?". Forbidden fruit: sex & religion in the lives of American teenagers. Oxford University Press US. pp. 290 pages. ISBN 9780195320947. http://books.google.com/books?id=F-Qu-FCNHBYC&pg=PA167&dq=Technical+virginity#v=onepage&q=Technical%20virginity&f=false. 
  36. ^ Jayson, Sharon (2005-10-19). "'Technical virginity' becomes part of teens' equation". USA Today. http://www.usatoday.com/news/health/2005-10-19-teens-technical-virginity_x.htm. Retrieved 2009-08-07. 
  37. ^ Joseph Gross, Michael (2003). Like a Virgin. The Advocate, Here Publishing. pp. 104 pages, Page 44. 0001-8996. http://books.google.com/?id=eWQEAAAAMBAJ&pg=PA44&dq=Gay+men+who+prefer+anal+sex#v=onepage&q&f=false. Retrieved 2011-03-13. 
  38. ^ Joe Perez (2006). Rising Up. Lulu.com. p. 248. ISBN 1411691733, 9781411691735. http://books.google.com/?id=caJ7gPv0DrAC&pg=PA191&dq=en#v=onepage&q=Bill%20Weintraub%20anal%20sex&f=false. Retrieved March 24, 2011. 
  39. ^ Steven Gregory Underwood (2003). Gay men and anal eroticism: tops, bottoms, and versatiles. Psychology Press. p. 225. ISBN 9781560233756. 1560233753, 9781560233756. http://books.google.com/?id=i4wRl0_8NuUC&pg=PA4&dq=#v=onepage&q&f=false. Retrieved 2011-02-12. 
  40. ^ Johnson, Ramone (2008-04-12). "Myth: All Gay Men Have Anal Sex". About.com. http://gaylife.about.com/b/2008/04/12/myth-all-gay-men-enjoy-anal-sex.htm. Retrieved 2011-02-12. 
  41. ^ "The New Sex Police". The Advocate. 2005-04-12. http://books.google.com/books?id=mGMEAAAAMBAJ&pg=PA39&dq=#v=onepage&q&f=false. Retrieved 2011-02-12. 
  42. ^ Dolby, Tom (February 2004). "Why Some Gay Men Don't Go All The Way". Out. http://books.google.com/books?id=jmIEAAAAMBAJ&pg=PA77&dq=en#v=onepage&q&f=false. Retrieved 2011-02-12. 
  43. ^ "Sexual and Reproductive Health: Women and Men". Guttmacher Institute. 2002. http://www.guttmacher.org/pubs/fb_10-02.html. Retrieved March 4, 2011. 
  44. ^ "Sexual Health Statistics for Teenagers and Young Adults in the United States" (PDF). Kaiser Family Foundation. September 2006. http://www.kff.org/womenshealth/upload/3040-03.pdf. Retrieved 2008-07-02. 
  45. ^ "Contraceptive Use". Guttmacher Institute. 2010. http://www.guttmacher.org/pubs/fb_contr_use.html. Retrieved March 4, 2011. 
  46. ^ Denis Campbell (January 22, 2006). "No sex please until we're at least 17 years old, we're British". The Observer. 
  47. ^ "Teen Sex Survey". Channel 4. 2008. http://sexperienceuk.channel4.com/teen-sex-survey. Retrieved August 5, 2011. 
  48. ^ Jonathan Thompson (November 12, 2006). "New safe sex ads target teens 'on the pull'". The Independent. 
  49. ^ a b "Findings from the National Survey of Sexual Health and Behavior, Centre for Sexual Health Promotion, Indiana University". The Journal of Sexual Medicine 7, Supplement 5.: 4. 2010. http://www.kinseyinstitute.org/resources/FAQ.html. Retrieved March 4, 2011. 
  50. ^ "Premature ejaculation". http://www.mayoclinic.com/health/premature-ejaculation/DS00578. Retrieved 2007-03-02. 
  51. ^ "Corty, E., & Guardiani, J. (2008) Canadian and American Sex Therapists' Perceptions of Normal and Abnormal Ejaculatory Latencies: How Long Should Intercourse Last?. The Journal of Sexual Medicine, 5(5), 1251-1256. DOI: 10.1111/j.1743-6109.2008.00797.x". .interscience.wiley.com. 2008-03-04. http://www3.interscience.wiley.com/journal/119425636/abstract?CRETRY=1&SRETRY=0. Retrieved 2010-11-23. 
  52. ^ "Sex therapists: Best sex is 7 to 13 min". Upi.com. 2008-03-05. http://www.upi.com/NewsTrack/Health/2008/03/05/sex_therapists_best_sex_is_7_to_13_min/6909/. Retrieved 2010-11-23. 
  53. ^ "Sexy time". Theglobeandmail.com. http://www.theglobeandmail.com/servlet/story/RTGAM.20080306.wlsex06/BNStory/lifeFamily/home?cid=al_gam_mostemail. Retrieved 2010-11-23. 
  54. ^ Giustozzi AA. Sexual dysfunction in women. In: Ferri FF. Ferri's Clinical Advisor 2010. St. Louis, Mo.: Mosby; 2009. [2]
  55. ^ "Mayo Clinic; Womans Health". Mayoclinic.com. http://www.mayoclinic.com/health/anorgasmia/DS01051. Retrieved 2010-11-23. 
  56. ^ Reissing ED, Binik YM, Khalifé S, Cohen D, Amsel R. ( 2003) Etiological correlates of vaginismus: sexual and physical abuse, sexual knowledge, sexual self-schema, and relationship adjustment. J Sex Marital Ther.29:47–59.
  57. ^ Ward E, Ogden J. (1994) Experiencing Vaginismus: sufferers beliefs about causes and effects. The Journal of Nervous and Mental Disease 9 (1): 33–45.
  58. ^ a b Frank JE, Mistretta P, Will J (March 2008). "Diagnosis and treatment of female sexual dysfunction". Am Fam Physician 77 (5): 635–42. PMID 18350761. 
  59. ^ Shafik A.; El-Sibai O.Journal of Obstetrics & Gynaecology, Volume 20, Number 3, 1 May 2000 , pp. 300–302(3)
  60. ^ Binik YM (February 2005). "Should dyspareunia be retained as a sexual dysfunction in DSM-V? A painful classification decision". Arch Sex Behav 34 (1): 11–21. doi:10.1007/s10508-005-0998-4. PMID 15772767. 
  61. ^ Peckham BM, Maki DG, Patterson JJ, Hafez GR (April 1986). "Focal vulvitis: a characteristic syndrome and cause of dyspareunia. Features, natural history, and management". Am J Obstet Gynecol. 154 (4): 855–64. PMID 3963075. 
  62. ^ Schouten BW, Bohnen AM, Groeneveld FP, Dohle GR, Thomas S, Bosch JL (July 2010). "Erectile dysfunction in the community: trends over time in incidence, prevalence, GP consultation and medication use--the Krimpen study: trends in ED". J Sex Med 7 (7): 2547–53. doi:10.1111/j.1743-6109.2010.01849.x. PMID 20497307. 
  63. ^ Heidelbaugh JJ (February 2010). "Management of erectile dysfunction". Am Fam Physician 81 (3): 305–12. PMID 20112889. 
  64. ^ Erectile Dysfunction Guideline Update Panel. AUA guideline on the pharmacologic management of premature ejaculation. Linthicum (MD): American Urological Association, Inc.; 2004. 19 p.[3]
  65. ^ Riley, A; Segraves, RT; R.T. Segraves (2006). "Treatment of Premature Ejaculation". Int J. Clin Pract. (Blackwell Publishing) 60 (6): 694–697. doi:10.1111/j.1368-5031.2006.00818.x. PMID 16805755. http://www.medscape.com/viewarticle/533889_print. Retrieved 2008-02-01. 
  66. ^ Hengeveld VW et al., Waldinger MD; Hengeveld, MW; Zwinderman, AH; Olivier, B (1998). "Effect of SSRI antidepressants on ejaculation: a double blind, randomised, placebo-controlled study with fluoxetine, fluvoxamine, paroxetine and sertraline". Journal of Clinical Psychopharmacology 18 (4): 274–281. doi:10.1097/00004714-199808000-00004. PMID 9690692. 
  67. ^ a b Williamson, Gail M.; Walters, Andrew S. (01). "Perceived Impact of Limb Amputation on Sexual Activity: A Study of Adult Amputees". The Journal of Sex Research (Lawrence Erlbaum Associates (Taylor & Francis Group)) 33 (3): 221–230. doi:10.1080/00224499609551838. ISSN 0022-4499. JSTOR 3813582. OCLC 39109327. 
  68. ^ Majiet, Shanaaz (01). "Disabled Women and Sexuality". Agenda (Agenda Feminist Media) (19): 43–44. doi:10.2307/4065995. JSTOR 4065995. 
  69. ^ Dewolfe, Deborah J.; Livingston, Carolyn A. (August 1, 1982). "Sexual Therapy for a Woman with Cerebral Palsy: A Case Analysis". The Journal of Sex Research (Lawrence Erlbaum Associates (Taylor & Francis Group)) 18 (3): 253–263. doi:10.1080/00224498209551151. ISSN 0022-4499. JSTOR 3812217. OCLC 39109327. 
  70. ^ Crowe LC, George WH (May 1989). "Alcohol and human sexuality: review and integration". Psychol Bull 105 (3): 374–86. doi:10.1037/0033-2909.105.3.374. PMID 2660179. 
  71. ^ Wood, H. Sex Cells Nature Reviews Neuroscience 4, 88 (February 2003) | doi:10.1038/nrn1044
  72. ^ Doheny, K. (2008) "10 Surprising Health Benefits of Sex," WebMD (reviewed by Chang, L., M.D.)
  73. ^ Light, K.C. et al., "More frequent partner hugs and higher oxytocin levels are linked to lower blood pressure and heart rate in premenopausal women." Biological Psychology, April 2005; vol 69: pp 5–21.
  74. ^ Charnetski CJ, Brennan FX. Sexual frequency and salivary immunoglobulin A (IgA). Psychological Reports 2004 Jun;94(3 Pt 1):839-44. Data on length of relationship and sexual satisfaction were not related to the group differences.
  75. ^ Michael F. Leitzmann; Edward Giovannucci. Frequency of Ejaculation and Risk of Prostate Cancer—Reply. JAMA. (2004);292:329.
  76. ^ Leitzmann MF, Platz EA, Stampfer MJ, Willett WC, Giovannucci E. Ejaculation Frequency and Subsequent Risk of Prostate Cancer. JAMA. (2004);291(13):1578–1586.
  77. ^ Giles GG, Severi G, English DR, et al. (August 2003). "Sexual factors and prostate cancer". BJU Int. 92 (3): 211–6. PMID 12887469. 
  78. ^ Lee HJ, Macbeth AH, Pagani JH, Young WS (June 2009). "Oxytocin: the great facilitator of life". Prog. Neurobiol. 88 (2): 127–51. doi:10.1016/j.pneurobio.2009.04.001. PMC 2689929. PMID 19482229. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2689929. 
  79. ^ Riley AJ. Oxytocin and coitus. Sexual and Relationship Therapy (1988);3:29–36
  80. ^ Carter CS. Oxytocin and sexual behavior. Neuroscience & Biobehavioral Reviews (1992);16(2):131–144
  81. ^ Blum, Jeffrey. "Can Good Sex Keep You Young?". WebMD. http://www.medicinenet.com/script/main/art.asp?articlekey=51501. Retrieved 8 October 2010. 
  82. ^ Weeks, David (1999). Secrets of the Superyoung. Berkley. p. 277. ISBN 978-0425172582. http://www.amazon.com/Secrets-Superyoung-David-Weeks/dp/0425172589/. 
  83. ^ Northrup, Christiane (2010). Women's Bodies, Women's Wisdom: Creating Physical and Emotional Health and Healing. Bantam. p. 960. ISBN 978-0553807936. http://books.google.com/books?id=V9S3keMnie8C&pg=PA232&lpg=PA232&dq=David+Weeks. 
  84. ^ "Common Sexually Transmitted Diseases (STDs)". U.S. Department of Health & Human Services.
  85. ^ http://www.who.int/mediacentre/factsheets/fs110/en/print.html
  86. ^ Weinstock H, et al. Sexually transmitted diseases among American youth: incidence and prevalence estimates, 2000. Perspectives on Sexual and Reproductive Health (2004);36(1):6–10.
  87. ^ Sex Infections Found in Quarter of Teenage Girls. The New York Times. March 12, 2008.
  88. ^ CDC. Sexual and Reproductive Health of Persons Aged 10–24 Years —United States, 2002–2007. MMWR 20009; 58 (No. SS-6):1–59 [4]
  89. ^ Yarnall KS, McBride CM, Lyna P, et al. (August 2003). "Factors associated with condom use among at-risk women students and nonstudents seen in managed care". Prev Med 37 (2): 163–70. doi:10.1016/S0091-7435(03)00109-9. PMID 12855216. 
  90. ^ Centers for Disease Control and Prevention. CDC Fact Sheet: Chlamydia. Accessed May 28, 2010
  91. ^ Kalwij S, Macintosh M, Baraitser P (2010). "Screening and treatment of Chlamydia trachomatis infections". BMJ 340: c1915. PMID 20410164. 
  92. ^ CDC Hepatitis B Information for Health Professionals Accessed May 27, 2010
  93. ^ a b "Hepatitis B". World Health Organization. http://www.who.int/mediacentre/factsheets/fs204/en/index.html. Retrieved 2009-09-19. 
  94. ^ Woods CR (June 2009). "Congenital syphilis-persisting pestilence". Pediatr. Infect. Dis. J. 28 (6): 536–7. doi:10.1097/INF.0b013e3181ac8a69. PMID 19483520. 
  95. ^ a b Centers for Disease Control and Prevention. CDC Fact Sheet: Syphilis. Accessed May 28, 2010
  96. ^ a b "HIV/AIDS". World Health Organization. http://www.who.int/hiv/en/index.html. Retrieved 2010-05-28. 
  97. ^ Centers for Disease Control and Prevention. CDC Fact Sheet: HIV/AIDS. Accessed May 28, 2010
  98. ^ "STI Epi Update: Oral Contraceptive and Condom Use". Public Health Agency of Canada. 1998-04-23. http://www.phac-aspc.gc.ca/publicat/epiu-aepi/std-mts/std511_e.html. Retrieved 2007-07-11. 
  99. ^ National Institute of Allergy and Infectious Diseases; National Institutes of Health, Department of Health and Human Services (2001-07-20). "Workshop Summary: Scientific Evidence on Condom Effectiveness for Sexually Transmitted Disease (STD) Prevention" (PDF). Hyatt Dulles Airport, Herndon, Virginia. pp. 13–15. Archived from the original on 2010-03-15. http://www.webcitation.org/5oFAVQUhH. Retrieved 2009-03-20. 
  100. ^ World Health Organization. Effectiveness of male latex condoms in protecting against pregnancy and sexually transmitted infections [5], 2000.
  101. ^ "Association of episodic physical and sexual activity with triggering of acute cardiac events: Systematic review and meta-analysis". JAMA 305 (12): 1225–1233. March 2011. doi:10.1001/jama.2011.336. http://jama.ama-assn.org/content/305/12/1225.abstract. Retrieved March 23, 2011. "Acute cardiac events were significantly associated with episodic physical and sexual activity; this association was attenuated among persons with high levels of habitual physical activity" 
  102. ^ a b The Joy of Sex: A Gourmet Guide to Lovemaking (1972)
  103. ^ Bramlett, M. D. and W. D. Mosher (2002). "Cohabitation, marriage, divorce, and remarriage in the United States." Vital & Health Statistics - Series 23, Data from the National Survey of Family Growth 22: 1-93.
  104. ^ a b Karney B. R., Bradbury T. N. (1995). "The longitudinal course of marital quality and stability: A review of theory, methods, and research". Psychological Bulletin 118 (1): 3–34. 
  105. ^ "Predicting sexual satisfaction in women: Implications for counselor education and training". Journal of Counseling & Development 82(2): 158–166. 2004. http://www.kinseyinstitute.org/resources/FAQ.html. Retrieved March 4, 2011. 
  106. ^ a b Ponton, Lynn (2000). The Sex Lives of Teenagers. New York: Dutton. p. 3. ISBN 978-0-452-28260-5. 
  107. ^ a b Garn, SM. Physical growth and development. In: Friedman SB, Fisher M, Schonberg SK. , editors. Comprehensive Adolescent Health Care. St Louis: Quality Medical Publishing; 1992. Retrieved on 2009-02-20
  108. ^ Jayson, Sharon (2005-10-19). "Teens define sex in new ways". USA Today. http://www.usatoday.com/news/health/2005-10-18-teens-sex_x.htm. Retrieved 2007-12-08. 
  109. ^ Mark O'Connell (March 9, 2005). "The epidemic of meaningless teen sex". The Boston Globe. http://www.boston.com/news/globe/editorial_opinion/oped/articles/2005/03/09/the_epidemic_of_meaningless_teen_sex/. Retrieved 2008-04-09. 
  110. ^ (Caspi et al.1993: Lanza and Collins, 2002)
  111. ^ (Stattin & Magnussion, 1990).
  112. ^ Denise D. Hallfors PhD, Martha W. Waller PhD, Daniel Bauer PhD, Carol A. Ford MD, and Carolyn T. Halpern PhD (2005). "Which Comes First in Adolescence—Sex and Drugs or Depression?" (PDF). American Journal of Preventive Medicine 29 (3): 163–170. doi:10.1016/j.amepre.2005.06.002. PMID 16168864. http://www.cpc.unc.edu/uploads/4823/1764/which_first_final.pdf. 
  113. ^ Katie Couric (2005). "Nearly 3 in 10 young teens 'sexually active'". MSNBC. http://www.msnbc.msn.com/id/6839072. Retrieved 2007-01-21. 
  114. ^ "Sex Education in the U.S.: Policy and Politics" (PDF). Issue Update. Kaiser Family Foundation. October 2002. http://www.kff.org/youthhivstds/upload/Sex-Education-in-the-U-S-Policy-and-Politics.pdf. Retrieved 2010-12-14. 
  115. ^ "Peer rejection tied to early sex in pre-teens" (PDF). Issue Update. MedlinePlus. October 2002. Archived from the original on 2007-10-11. http://web.archive.org/web/20071011012252/http://www.nlm.nih.gov/medlineplus/news/fullstory_55689.html. Retrieved August 5, 2011. 
  116. ^ R.S.Goya, Indian Institute of Health Management Research, Jaipur, India (2005). "Socio-psychological Constructs of Premarital Sex Behavior among Adolescent Girls in India" (PDF). Abstract. Princeton University. http://iussp2005.princeton.edu/download.aspx?submissionId=50332. Retrieved August 5, 2011. 
  117. ^ William N. Eskridge Jr. Dishonorable Passions: Sodomy Laws in America, 1861–2003. (2008) Viking Adult. ISBN 0670018627
  118. ^ Noelle N. R. Quenivet. Sexual Offenses in Armed Conflict & International Law. (2005) Hotei Publishing. ISBN 1571053417
  119. ^ Marshall Cavendish Corporation Staff. Sex and Society. (2009) Cavendish, Marshall Corporation. p143-144. ISBN 0761479066 [6]
  120. ^ Jerrold S. Greenberg, Clint E. Bruess, Sarah C. Conklin. (2010). Exploring the Dimensions of Human Sexuality. p 515. ISBN 0763776602 [7].
  121. ^ Karen L. Kinnear. (2007) Childhood sexual abuse: a reference handbook. ABC-CLIO. ISBN 1851099050 [8]
  122. ^ Reed, E. J. (1997). "Criminal Law and the Capacity of Mentally Retarded Persons to Consent to Sexual Activity". Virginia Law Review 83 (4): 799–827. doi:10.2307/1073749. JSTOR 1073749. 
  123. ^ The Sexual Offences Act 2003 (Commencement) Order 2004 (S.I. 2004/874)
  124. ^ R v Gaston 73 Cr App R 164, CA
  125. ^ R v R'Rue (1838) 8 C & P 641; R v Allen (1839) 9 C & P 31
  126. ^ Archbold Criminal Pleading, Evidence and Practice, 1999, paragraph 20-24
  127. ^ "Laws of New York, leginfo.state.ny". Public.leginfo.state.ny.us. http://public.leginfo.state.ny.us/LAWSSEAF.cgi?QUERYDATA=@PLPEN0P3THA130. Retrieved 2011-07-30. 
  128. ^ Janet Afary. Sexual Politics in Modern Iran. (2009) Cambridge University Press. ISBN 0521898463
  129. ^ Daniel L. Akin. God on Sex: The Creator's Ideas About Love, Intimacy, and Marriage. (2003) B&H Publishing Group. ISBN 0805425969
  130. ^ a b c Don S. Browning, Martha Christian Green, John Witte. Sex, marriage, and family in world religions. (2006) Columbia University Press. ISBN 023113116X [9]
  131. ^ Abdul Rahman bin Abdul Karim al-Sheha. Islamic Perspective of Sex (2003) Saudi Arabia. ISBN 9960431401
  132. ^ Fatima M. D'Oyen. The Miracle of Life. (2007)Islamic Foundation (UK). ISBN 086037355X
  133. ^ Judaism 101:. "Kosher Sex". http://www.jewfaq.org/sex.htm. Retrieved August 11, 2011. 
  134. ^ Thompson, Lady Gwen; Wiccan-Pagan Potpourri; Green Egg, №69; Ostara 1974
  135. ^ Hans Holzer. The Truth about Witchcraft (1971) Doubleday. page 128. ISBN 0090048601
  136. ^ Kenneth E. Bowers. God Speaks Again: An Introduction to the Baha'i Faith. (2004) Baha'i Publishing. ISBN 1931847126
  137. ^ John A. Buehrens and Forrest Church. A Chosen Faith: An Introduction to Unitarian Universalism. (1998) Beacon Press. ISBN 0807016179
  138. ^ Hodgkinson, Liz (2002). Peace and Purity: The Story of the Brahma Kumaris a Spiritual Revolution. HCI. pp. 2–29. ISBN 1558749624. 
  139. ^ Babb, Lawrence A. (1987). Redemptive Encounters: Three Modern Styles in the Hindu Tradition (Comparative Studies in Religion and Society). Oxford University Press. ISBN 0706925637. "Sexual intercourse is unnecessary for reproduction because the souls that enter the world during the first half of the Cycle are in possession of a special yogic power (yog bal) by which they conceive children"
  140. ^ Barrett, David V (2001). The New Believers. Cassell & Co. pp. 265. ISBN 0-304-35592-5.
  141. ^ Chase, Stacey (July 23, 2006). "The Last Ones Standing". The Boston Globe. http://www.boston.com/news/globe/magazine/articles/2006/07/23/the_last_ones_standing/?page=full. 
  142. ^ Baba, Meher (1995). Discourses. Myrtle Beach: Sheriar Press. p. 109. ISBN 9781880619094.
  143. ^ William Skudlarek. Demythologizing Celibacy: Practical Wisdom from Christian and Buddhist Monasticism. (2008) Liturgical Press. ISBN 0814629474
  144. ^ Naomi R. Cahn, June Carbone (2010). Red families v. blue families: legal polarization and the creation of culture. Oxford University Press US. p. 288. ISBN 0195372174, 9780195372175. http://books.google.com/?id=F6eeGny49J4C&pg=PA129&dq=Opposition+to+gay+marriage+is+about+gay+sex#v=onepage&q=Opposition%20to%20gay%20marriage%20is%20about%20gay%20sex&f=false. Retrieved July 29, 2011. 
  145. ^ Donald J. Cantor (2006). Same-sex marriage: the legal and psychological evolution in America. Wesleyan University Press. p. 191. ISBN 0819568120, 9780819568120. http://books.google.com/?id=lydHmmrHB8QC&printsec=frontcover&dq=Gay+marriage+and+sex#v=onepage&q=Gay%20marriage%20and%20sex&f=false. Retrieved July 29, 2011. 
  146. ^ American Psychological Association (2004). "Resolution on Sexual Orientation and Marriage". http://www.apa.org/about/governance/council/policy/gay-marriage.pdf. Retrieved July 29, 2011. 
  147. ^ American Psychiatric Association (2005). "Support of Legal Recognition of Same-Sex Civil Marriage". http://archive.psych.org/edu/other_res/lib_archives/archives/200502.pdf. Retrieved July 29, 2011. 
  148. ^ American Psychoanalytic Association. "Position Paper On Gay Marriage". http://www.apsa.org/About_APsaA/Position_Statements/Gay_Marriage.aspx. Retrieved July 29, 2011. 
  149. ^ American Sociological Association. "American Sociological Association Member Resolution on Proposed U.S. Constitutional Amendment Regarding Marriage". http://www2.asanet.org/public/marriage_res.html. Retrieved July 29, 2011. 
  150. ^ K. Smith, Susan (July 30, 2009). "Marriage a Civil Right, not Sacred Rite". The Washington Post. http://newsweek.washingtonpost.com/onfaith/panelists/susan_k_smith/2009/07/marriage_a_civil_right_not_sacred_rite.html. Retrieved July 28, 2011. 
  151. ^ Taylor, Pamela K. (July 31, 2009). "Marriage: Both Civil and Religious". The Washington Post. http://newsweek.washingtonpost.com/onfaith/panelists/pamela_k_taylor/2009/07/marriage_both_civil_and_religious.html. Retrieved July 28, 2011. 
  152. ^ "Decision in Perry v. Schwarzenegger". ecf.cand.uscourts.gov. July 31, 2009. https://ecf.cand.uscourts.gov/cand/09cv2292/files/09cv2292-ORDER.pdf. Retrieved July 28, 2011. 
  153. ^ Ruppert, E.E., Fox, R.S., and Barnes, R.D. (2004). "Chelicerata: Araneae". Invertebrate Zoology (7 ed.). Brooks / Cole. pp. 571–584. ISBN 0030259827. 

External links


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Sexual intercourse — Intercourse In ter*course, n. [Formerly entercourse, OF. entrecours commerce, exchange, F. entrecours a reciprocal right on neighboring lands, L. intercursus a running between, fr. intercurrere to run between. See {Inter }, and {Course}.] 1. A… …   The Collaborative International Dictionary of English

  • sexual intercourse — noun uncount FORMAL the act of having sex, especially sex between a man and woman in which the man puts his PENIS inside the woman s VAGINA. Sexual intercourse is often simply called intercourse …   Usage of the words and phrases in modern English

  • sexual intercourse — n 1) heterosexual intercourse involving penetration of the vagina by the penis: COITUS 2) intercourse (as anal or oral intercourse) that does not involve penetration of the vagina by the penis * * * see coitus * * * 1. coitus. 2. any physical… …   Medical dictionary

  • sexual intercourse — n. 1. a joining of the sexual organs of a male and a female, in which the erect penis of the male is inserted into the vagina of the female, usually with the ejaculation of semen into the vagina 2. INTERCOURSE (sense 2b) …   English World dictionary

  • sexual intercourse — ► NOUN ▪ sexual contact between individuals involving penetration, especially the insertion of a man s erect penis into a woman s vagina culminating in orgasm and the ejaculation of semen …   English terms dictionary

  • sexual intercourse — n [U] formal the physical activity of two people having sex with each other …   Dictionary of contemporary English

  • sexual intercourse — genital contact, esp. the insertion of the penis into the vagina followed by orgasm; coitus; copulation. [1790 1800] * * * or coitus or copulation Act in which the male reproductive organ enters the female reproductive tract (see reproductive… …   Universalium

  • sexual intercourse —    copulation    Not just dealings or conversation between individuals. Now standard English:     If he gets pinched with a girl in a hotel room, stop sexual intercourse. (Chandler, 1953)    Sexual commerce is archaic, and there was no suggestion …   How not to say what you mean: A dictionary of euphemisms

  • sexual intercourse —   Ai, ei, hana ma i, moe, pi i, panipani, aina.    ♦ Motions of sexual intercourse, kū ami ami.    ♦ To have had sexual intercourse, of a female, pā kanaka.    ♦ Sexual intercourse with a menstruating woman, kokokohe …   English-Hawaiian dictionary

  • sexual intercourse — n. to have sexual intercourse with * * * to have sexual intercourse with …   Combinatory dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”