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Sexual intercourse

Sexual intercourse is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sexual intercourse rather than just read about it. In short: Sex, more formally known as sexual intercourse, coitus, or copulation, is an intimate social activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for erotic pleasure, biological reproduction, or both. This specific type of sex is also known as vaginal intercourse (or vaginal sex).

Sexual intercourse — main illustration
Sexual intercourse — illustration

Key takeaways

  • Sexual intercourse belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Sexual intercourse to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Sexual intercourse from memory before moving on to harder problems.

Reference excerpt

Sex, more formally known as sexual intercourse, coitus, or copulation, is an intimate social activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for erotic pleasure, biological reproduction, or both. This specific type of sex is also known as vaginal intercourse (or vaginal sex). However, other forms of penetrative sexual intercourse also exist, including anal sex (penetration of the anus by the penis), oral sex (penetration of the mouth by the penis or oral contact with or penetration of the female genitalia), fingering (sexual penetration by the fingers) and penetration by use of a dildo (especially a strap-on dildo), and vibrators. The desire for these activities is grounded in natural human instinct and they involve physical intimacy between two or more people, usually enacted by humans solely for physical-emotional pleasure, sometimes contributing to human bonding. There are different views on what constitutes sexual intercourse or other sexual activity, which can impact views of sexual health. Although sexual intercourse, particularly the term coitus, generally denotes penile–vaginal penetration and the possibility of creating offspring, it also commonly denotes penetrative oral sex and penile–anal sex, especially the latter. It usually encompasses any sexual penetration (a term especially common in statutory law), while non-penetrative sex has been labeled outercourse, but non-penetrative sex may also be considered sexual intercourse by some people or in some less-common definitions. Because people can be at risk of contracting sexually transmitted infections during these activities, safer sex practices are recommended by health professionals to reduce transmission risk. Various jurisdictions place restrictions on certain sexual acts, such as adultery, incest, sexual activity with minors, prostitution, rape, zoophilia, sodomy, premarital sex and extramarital sex. Religious beliefs also play a role in personal decisions about sexual intercourse or other sexual activity, such as decisions about virginity, or legal and public policy matters. Religious views on sexuality vary significantly between different religions and sects of the same religion, though there are common themes, such as prohibition of adultery. Reproductive sexual intercourse between non-human animals is more often called copulation, and sperm may be introduced into the female's reproductive tract in non-vaginal ways among the animals, such as by cloacal copulation. For most non-human mammals, mating and copulation occur at the point of estrus (the most fertile period of time in the female's reproductive cycle), which increases the chances of successful impregnation. However, bonobos, dolphins and chimpanzees are known to engage in sexual intercourse regardless of whether the female is in estrus, and to engage in sex acts with same-sex partners. Like humans engaging in sexual activity primarily for pleasure, this behavior in these animals is also presumed to be for pleasure, and a contributing factor to strengthening their social bonds.

Behaviors

Definitions

Sexual intercourse may be called coitus, copulation, coition, or intercourse. Coitus is derived from the Latin word coitio or coire, meaning "a coming together or joining together" or "to go together", and is known under different ancient Latin names for a variety of sexual activities, but usually denotes penile–vaginal penetration. This is often called vaginal intercourse or vaginal sex. Vaginal sex, and less often vaginal intercourse, may also denote any vaginal sexual activity, particularly if penetrative, including sexual activity between lesbian couples. Copulation, by contrast, more often denotes the mating process, especially for non-human animals; it can mean a variety of sexual activities between opposite-sex or same-sex pairings, but generally means the sexually reproductive act of transferring sperm from a male to a female or sexual procreation between a man and a woman. Although sex and having sex also most commonly denote penile–vaginal intercourse, sex can be significantly broad in its meaning and may cover any penetrative or non-penetrative sexual activity between two or more people. The World Health Organization (WHO) states that non-English languages and cultures use different words for sexual activity, "with slightly different meanings". Various vulgarisms, slang, and euphemisms are used for sexual intercourse or other sexual activity, such as fuck, screw, shag, and the phrase "sleep together". The laws of some countries use the euphemism, carnal knowledge. Penetration of the vagina by the erect penis is additionally known as intromission, or by the Latin name immissio penis (Latin for "insertion of the penis"). The age of first sexual intercourse is called sexarche. Vaginal, anal and oral sex are recognized as sexual intercourse more often than other sexual behaviors. Sexual activity that does not involve penile-vaginal sex or other sexual penetration might be used to retain virginity (sometimes called technical virginity) or labeled outercourse. One reason virginity loss is often based on penile–vaginal intercourse is because heterosexual couples may engage in anal or oral sex as a way of being sexually active while maintaining that they are virgins since they have not engaged in the reproductive act of coitus. Some gay men consider frot or oral sex as a way of maintaining their virginities, with penile-anal penetration used as sexual intercourse and for virginity loss, while other gay men may consider frot or oral sex as their main forms of sexual activity. Lesbians may categorize oral sex or fingering as sexual intercourse and subsequently an act of virginity loss, or tribadism as a primary form of sexual activity.

… excerpt ends here. Continue reading the full article.

Illustrations

Sexual intercourse: The missionary position, painted by Édouard-Henri Avril (1892), inspired by the erotic sonnets of Pietro Aretino
The missionary position, painted by Édouard-Henri Avril (1892), inspired by the erotic sonnets of Pietro Aretino
Sexual intercourse: 19th-century erotic interpretation of Roman emperor Hadrian and Antinous engaged in anal intercourse, by Édouard-Henri Avril
19th-century erotic interpretation of Roman emperor Hadrian and Antinous engaged in anal intercourse, by Édouard-Henri Avril
Sexual intercourse: Plates 15 and 16 from John Roberton's The Generative System (1824). Plate 15 (left) shows the adaptation of the glans penis and vagina during intercourse; Plate 16 (right) illustrates the suction and collapse of the vagina.
Plates 15 and 16 from John Roberton's The Generative System (1824). Plate 15 (left) shows the adaptation of the glans penis and vagina during intercourse; Plate 16 (right) illustrates the suction and collapse of the vagina.
Sexual intercourse: Édouard-Henri Avril depiction of a woman on top position, a position that is more likely to stimulate the clitoris[58]
Édouard-Henri Avril depiction of a woman on top position, a position that is more likely to stimulate the clitoris[58]
Sexual intercourse: Édouard-Henri Avril depiction of cunnilingus in the life of Sappho
Édouard-Henri Avril depiction of cunnilingus in the life of Sappho

Worked examples

Example 1 — a first encounter with Sexual intercourse

Start with the simplest possible case. Write down what Sexual intercourse claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sexual intercourse before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sexual intercourse ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sexual intercourse

In research
Sexual intercourse appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Sexual intercourse in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Sexual intercourse is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fertility, Health risk, Human reproduction, so understanding it makes those chapters shorter.
In everyday life
Look for Sexual intercourse outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sexual intercourse in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Sexual intercourse means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Sexual intercourse out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sexual intercourse in simple terms?

Sex, more formally known as sexual intercourse, coitus, or copulation, is an intimate social activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for erotic pleasure, biological reproduction, or both. This specific type of sex…

Why does Sexual intercourse matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sexual intercourse?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sexual intercourse.

Tags

  • Fertility
  • Health risk
  • Human reproduction
  • Interpersonal relationships
  • Mating
  • Sexology
  • Sexual acts
  • Sexual intercourse

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