In England and its successor states, it has been  high treason  to engage in adultery with the King's wife, his eldest son's wife and his eldest unmarried daughter. The jurist Sir William Blackstone writes that "the plain intention of this law is to guard the Blood Royal from any suspicion of bastardy, whereby the succession to the Crown might be rendered dubious." Adultery was a serious issue when it came to succession to the crown.  Philip IV of France  had all three of his daughters-in-law imprisoned, two ( Margaret of Burgundy  and  Blanche of Burgundy ) on the grounds of adultery and the third ( Joan of Burgundy ) for being aware of their adulterous behaviour. The two brothers accused of being lovers of the king's daughters-in-law were executed immediately after being arrested. The wife of Philip IV's eldest son bore a daughter, the future  Joan II of Navarre , whose paternity and succession rights were disputed all her life. [ 148 ]


The  christianization of Europe  came to mean that, in theory, and unlike with the Romans, there was supposed to be a single sexual standard, where adultery was a sin and against the teachings of the church, regardless of the sex of those involved. In practice, however, the church seemed to have accepted the traditional double standard which punished the adultery of the wife more harshly than that of the husband. [ 149 ]  Among Germanic tribes, each tribe had its own laws for adultery, and many of them allowed the husband to "take the law in his hands" and commit acts of violence against a wife caught committing adultery. [ 149 ] [ 150 ]  In the Middle Ages, adultery in  Vienna  was punishable by death through  impalement . [ 151 ]   Austria  was one of the last Western countries to decriminalize adultery, in 1997. [ 152 ]


The  Encyclopedia of Diderot & d'Alembert , Vol. 1 (1751) noted the legal double standard from that period, it wrote: [ 26 ]


"Furthermore, although the husband who violates conjugal trust is guilty as well as the woman, it is not permitted for her to accuse him, nor to pursue him because of this crime".


Historically, many cultures considered adultery a very serious  crime , some subject to severe punishment, especially for the married woman and sometimes for her sex partner, with penalties including  capital punishment ,  mutilation , or  torture . [ 4 ]  Such punishments have gradually fallen into disfavor, especially in  Western countries  from the 19th century. In countries where adultery is still a criminal offense, punishments range from  fines  to  caning [ 5 ]  and even capital punishment. Since the 20th century, such laws have become controversial, with most Western countries repealing them.


However, even in jurisdictions that have decriminalised adultery, adultery may still have legal consequences, particularly in jurisdictions with fault-based  divorce  laws, where adultery almost always constitutes a  ground for divorce  and may be a factor in  property settlement , the  custody  of children, the denial of  alimony , etc. Adultery is not a ground for divorce in jurisdictions which have adopted a  no-fault divorce  model, but may still be a factor in child custody and property disputes.


International organizations [ which? ]  have called for the decriminalising of adultery, especially in the light of several high-profile  stoning  cases that have occurred in some countries. [ which? ]  The head of the United Nations expert body charged with identifying ways to eliminate laws that discriminate against women or are discriminatory to them in terms of implementation or impact,  Kamala Chandrakirana , has stated that: "Adultery must not be classified as a criminal offence at all". [ 6 ]  A joint statement by the United Nations Working Group on discrimination against women in law and in practice states that: "Adultery as a criminal offence violates women’s human rights". [ 7 ]


In Muslim countries that follow  Sharia law  for criminal justice, the punishment for adultery may be stoning. [ 8 ]  There are 15 [ 9 ]  countries in which stoning is authorized as lawful punishment, though in recent times it has been legally carried out only in Iran and Somalia. [ 10 ]  Most countries that criminalize adultery are those where the dominant religion is Islam, and several  Sub-Saharan African  Christian-majority countries, but there are some notable exceptions to this rule, namely, the Philippines and several U.S. states.


In jurisdictions where adultery is illegal, punishments vary from fines (for example in the US state of  Rhode Island [ 153 ] ) to caning in parts of Asia. [ 154 ] [ 155 ]  In 15 countries [ 9 ]  the punishment includes  stoning , although in recent times it has been legally enforced only in Iran and Somalia. [ 10 ]  Most stoning cases are the result of  mob violence , and while technically illegal, no action is usually taken against perpetrators. Sometimes such stonings are ordered by informal village leaders who have  de facto  power in the community. [ 156 ]  Adultery may have consequences under  civil law  even in countries where it is not outlawed by the  criminal law . For instance it may constitute  fault  in countries where the  divorce law  is  fault based  or it may be a ground for  tort .


In some jurisdictions, the "intruder" (the third party) is punished, rather than the adulterous spouse. For instance art 266 of the Penal Code of South Sudan reads: "Whoever, has consensual sexual intercourse with a man or woman who is and whom he or she has reason to believe to be the spouse of another person, commits the offence of adultery [...]". [ 157 ]  Similarly, under the  adultery law in India  (Section 497 of the Indian Penal Code, until overturned by the Supreme Court in 2018) it was a criminal offense for a man to have consensual sexual intercourse with a married woman, without the consent of her husband (no party was criminally punished in case of intercourse between a married man and an unmarried woman).


Historically, paternity of children born out of adultery has been seen as a major issue. Modern advances such as reliable  contraception  and  paternity testing  have changed the situation (in Western countries). Most countries nevertheless have a legal presumption that a woman's husband is the father of her children who were born during that marriage. Although this is often merely a  rebuttable presumption , many jurisdictions have laws which restrict the possibility of legal rebuttal (for instance by creating a legal time limit during which paternity may be challenged – such as a certain number of years from the birth of the child). [ 158 ]  Establishing correct paternity may have major legal implications, for instance in regard to  inheritance .


Children born out of adultery suffered, until recently, adverse legal and social consequences. In  France , for instance, a law that stated that the inheritance rights of a child born under such circumstances were, on the part of the married parent, half of what they would have been under ordinary circumstances, remained in force until 2001, when France was forced to change it by a ruling of the  European Court of Human Rights  (ECtHR) (and in 2013, the ECtHR also ruled that the new 2001 regulations must be also applied to children born  before  2001). [ 159 ]


There has been, in recent years, a trend of legally favoring the right to a relation between the child and its biological father, rather than preserving the appearances of the 'social' family. In 2010, the ECtHR ruled in favor of a German man who had fathered twins with a married woman, granting him right of contact with the twins, despite the fact that the mother and her husband had forbidden him from seeing the children. [ 160 ]


Laws against adultery have been named as invasive and incompatible with principles of  limited government . [ citation needed ]  Much of the criticism comes from  libertarianism , the consensus among whose adherents is that government must not intrude into daily personal lives and that such disputes are to be settled privately rather than  prosecuted  and  penalized  by  public entities . It is also argued that adultery laws are rooted in religious doctrines; which should not be the case for laws in a  secular state .


Historically, in most cultures, laws against adultery were enacted only to prevent women—and not men—from having sexual relations with anyone other than their spouses, [ citation needed ]  with adultery being often defined as sexual intercourse between a married woman and a man other than her husband. [ citation needed ]  Among many cultures the  penalty  was—and to this day still is, as noted  below — capital punishment . At the same time, men were free to maintain sexual relations with any women ( polygyny ) provided that the women did not already have husbands or "owners". Indeed,  בעל  (ba`al), Hebrew for  husband , used throughout the  Bible , is synonymous with  owner . These laws were enacted in fear of  cuckoldry  and thus  sexual jealousy . Many indigenous customs, such as  female genital mutilation [ 161 ]  and even  menstrual taboos , [ 162 ]  have been theorized to have originated as preventive measures against cuckolding. This arrangement has been deplored by many modern intellectuals.


Opponents of adultery laws argue that these laws maintain social norms which justify violence, discrimination and oppression of women; in the form of state sanctioned forms of violence such as  stoning ,  flogging  or  hanging  for adultery; or in the form of individual acts of violence committed against women by husbands or relatives, such as  honor killings ,  crimes of passion , and beatings. [ 19 ] [ 163 ]   UN Women  has called for the decriminalization of adultery. [ 163 ]


An argument against the criminal status of adultery is that the resources of the law enforcement are limited, and that they should be used carefully; by investing them in the investigation and prosecution of adultery (which is very difficult) the curbing of serious violent crimes may suffer. [ 164 ]


Human rights organizations have stated that legislation on sexual crimes must be based on  consent , and must recognize consent as central, and not trivialize its importance; doing otherwise can lead to legal, social or ethical abuses. Amnesty International, when condemning stoning legislation that targets adultery, among other acts, has referred to "acts which should never be criminalized in the first place, including consensual sexual relations between adults". [ 165 ]  Salil Shetty, Amnesty International's Secretary General, said: "It is unbelievable that in the twenty-first century some countries are condoning  child marriage  and  marital rape  while others are outlawing abortion, sex outside marriage and same-sex sexual activity – even punishable by death." [ 166 ]  The  My Body My Rights  campaign has condemned state control over individual sexual and reproductive decisions; stating "All over the world, people are coerced, criminalized and discriminated against, simply for making choices about their bodies and their lives". [ 167 ]


For various reasons, most couples who marry do so with the expectation of  fidelity . Adultery is often seen as a breach of trust and of the commitment that had been made during the act of marriage. [ 168 ]  Adultery can be emotionally traumatic for both spouses and often results in divorce. [ 169 ]


Adultery may lead to ostracization from certain religious or social groups. [ 170 ]


Adultery can also lead to feelings of guilt and jealousy in the person with whom the affair is being committed. In some cases, this "third person" may encourage divorce (either openly or subtly). [ 171 ]  If the cheating spouse has hinted at divorce to continue the affair, the third person may feel deceived if that does not happen. [ 172 ] [ 173 ]  They may simply withdraw with ongoing feelings of guilt, carry on an obsession with their lover, may choose to reveal the affair, or in rare cases, commit violence or other crimes. [ 174 ]


There is correlation between divorces and children having struggles in later life. [ 175 ]


Like any sexual contact, extramarital sex opens the possibility of the introduction of sexually-transmitted diseases (STDs) into a marriage. Since most married couples do not routinely use  barrier contraceptives , [ citation needed ]  STDs can be introduced to a marriage partner by a spouse engaging in unprotected extramarital sex. This can be a  public health  issue in regions of the world where STDs are common, but addressing this issue is very difficult due to legal and social barriers – to openly talk about this situation would mean to acknowledge that adultery (often) takes place, something that is taboo in certain cultures, especially those strongly influenced by religion. In addition, dealing with the issue of barrier contraception in marriage in cultures where women have very few rights is difficult: the power of women to negotiate safer sex (or sex in general) with their husbands is often limited. [ 176 ] [ 177 ] [ 178 ]  The  World Health Organization  (WHO) found that women in violent relations were at increased risk of  HIV/AIDS , because they found it very difficult to negotiate safe sex with their partners, or to seek medical advice if they thought they have been infected. [ 179 ]


Historically, female adultery often resulted in extreme violence, including  murder  (of the woman, her lover, or both, committed by her husband). Today, domestic violence is outlawed in most countries.


Marital infidelity has been used, especially in the past, as a  legal defence  of  provocation  to a criminal charge, such as murder or assault. In some jurisdictions, the defence of provocation has been replaced by a  partial defence  or provocation or the behaviour of the victim can be invoked as a  mitigating factor  in sentencing.


In recent decades, feminists and women's rights organizations have worked to change laws and social norms which tolerate  crimes of passion  against women.  UN Women  has urged states to review legal defenses of passion and provocation, and other similar laws, to ensure that such laws do not lead to impunity in regard to  violence against women , stating that "laws should clearly state that these defenses do not include or apply to crimes of "honour", adultery, or  domestic assault  or murder." [ 180 ]


The  Council of Europe  Recommendation Rec(2002)5 of the Committee of Ministers to member states on the protection of women against violence [ 181 ]  states that member states should "preclude adultery as an excuse for violence within the family".


Honor killings  are often connected to accusations of adultery. Honor killings  continue to be practiced in some parts of the world , particularly (but not only) in parts of South Asia and the Middle East. Honor killings are treated leniently in some legal systems. [ 182 ]  Honor killings have also taken place in immigrant communities in Europe, Canada and the U.S. In some parts of the world, honor killings enjoy considerable public support: in one survey, 33.4% of teenagers in Jordan's capital city, Amman, approved of honor killings. [ 183 ]  A survey in  Diyarbakir , Turkey, found that, when asked the appropriate punishment for a woman who has committed adultery, 37% of respondents said she should be killed, while 21% said her nose or ears should be cut off. [ 184 ]


Until 2009, in  Syria , it was legal for a husband to kill or injure his wife or his female relatives caught  in flagrante delicto  committing adultery or other illegitimate sexual acts. The law has changed to allow the perpetrator to only "benefit from the attenuating circumstances, provided that he serves a prison term of no less than two years in the case of killing." [ 185 ]  Other articles also provide for reduced sentences. Article 192 states that a judge may opt for reduced punishments (such as short-term imprisonment) if the killing was done with an honorable intent. Article 242 says that a judge may reduce a sentence for murders that were done in rage and caused by an illegal act committed by the victim. [ 186 ]  In recent years, Jordan has amended its Criminal Code to modify its laws which used to offer a complete defense for honor killings. [ 187 ]


According to the UN in 2002:


Crimes of passion  are often triggered by jealousy, and, according to  Human Rights Watch , "have a similar dynamic [to honor killings] in that the women are killed by male family members and the crimes are perceived as excusable or understandable." [ 190 ]


Stoning , or lapidation, refers to a form of  capital punishment  whereby an organized group throws stones at an individual until the person dies, or the condemned person is pushed from a platform set high enough above a stone floor that the fall would probably result in instantaneous death. [ 191 ]


Stoning continues to be practiced today, in parts of the world. Recently, several people have been sentenced to death by stoning after being accused of adultery in Iran, Somalia, Afghanistan, Sudan, Mali, and Pakistan by tribal courts. [ 192 ]


In some jurisdictions  flogging  is a punishment for adultery. [ 193 ] [ 194 ]  There are also incidents of extrajudicial floggings, ordered by informal religious courts. In 2011, a 14-year-old girl in Bangladesh died after being publicly lashed, when she was accused of having an affair with a married man. Her punishment was ordered by villagers under Sharia law. [ 195 ] [ 196 ]


Married people who form relations with extramarital partners or people who engage in relations with partners married to somebody else may be subjected to violence in these relations. [ 197 ] [ 198 ]  Because of the nature of adultery – illicit or illegal in many societies – this type of intimate partner violence may go underreported or may not be prosecuted when it is reported; and in some jurisdictions this type of violence is not covered by the specific  domestic violence  laws meant to protect persons in legitimate couples. [ 199 ] [ 200 ]


The theme of adultery has been used in many literary works, and has served as a theme for notable books such as  Anna Karenina ,  Madame Bovary ,  Lady Chatterley's Lover ,  The Scarlet Letter  and  Adultery . It has also been the theme of many movies.


Adultery laws  are the laws in various countries that deal with  extramarital sex . Historically, many cultures considered  adultery  a very serious  crime , some subject to severe punishment, especially in the case of extramarital sex involving a married woman and a man other than her husband, with penalties including  capital punishment ,  mutilation , or  torture . [ 1 ]  Such punishments have gradually fallen into disfavor, especially in  Western countries  from the 19th century. In countries where adultery is still a criminal offense, punishments range from  fines  to  caning [ 2 ]  and even capital punishment. Since the 20th century, criminal laws against adultery have become controversial, with most Western countries repealing them.


Most countries that criminalize adultery are those where the  dominant religion is Islam , and several  sub-Saharan African   Christian-majority countries . Notable exceptions to this rule are the  Philippines  and 17  U.S. states  (as well as Puerto Rico) although adultery charges are rare in the United States.


However, even in jurisdictions that have decriminalised adultery, adultery may still have legal consequences, particularly in jurisdictions with  fault-based divorce  laws, where adultery can constitute a  ground for divorce  and may be a factor in  property settlement , the  custody of children , the denial of  alimony , etc. Adultery is not a ground for divorce in jurisdictions which have adopted a  no-fault divorce  model, but may still be a factor in child custody and property disputes.


The criminal status of adultery has attracted criticism, especially where there are violent penalties. The head of the United Nations expert body charged with identifying ways to eliminate laws that discriminate against women or are discriminatory to them in terms of implementation or impact,  Kamala Chandrakirana , has stated that: "Adultery must not be classified as a criminal offence at all". [ 3 ]  A joint statement by the United Nations Working Group on discrimination against women in law and in practice states that: "Adultery as a criminal offence violates women’s human rights". [ 4 ]


In Muslim countries that follow  Sharia law  for criminal justice, the punishment for adultery may be  stoning . [ 5 ]  There are fifteen [ 6 ]  countries in which stoning is authorized as lawful punishment, though in recent times it has been legally carried out only in Iran and Somalia. [ 7 ]
Countries which follow very strict versions of Sharia law in their criminal systems include Saudi Arabia, Iran, Brunei, Afghanistan, Sudan, Pakistan, 12 of Nigeria's 36 states (in Northern Nigeria) and Qatar; although these laws are not necessarily enforced. [ 8 ]   Al-Shabaab , a jihadist fundamentalist group based in East Africa (mainly Somalia) and Yemen also implements an extreme form of Sharia. [ 8 ]


In jurisdictions where adultery is illegal, punishments vary from fines (for example in the US state of  Rhode Island [ 9 ] ) to caning in parts of Asia. [ 10 ] [ 11 ]  In fifteen countries [ 6 ]  the punishment includes  stoning , although in recent times it has been legally enforced only in Iran and Somalia. [ 7 ]  Most stoning cases are the result of  mob violence , and while technically illegal, no action is usually taken against perpetrators. Sometimes such stonings are ordered by informal village leaders who have  de facto  power in the community. [ 12 ]  Adultery may have consequences under  civil law  even in countries where it is not outlawed by the  criminal law . For instance it may constitute  fault  in countries where the  divorce law  is  fault based  or it may be a ground for  tort .


In some jurisdictions, the "intruder" (the third party) is punished, rather than the adulterous spouse. For instance act 266 of the Penal Code of South Sudan reads: "Whoever,  has  consensual  sexual intercourse  with  a  man  or woman who is and whom he or she has reason to believe to be the spouse of another person, commits the offence of adultery [...]". [ 13 ]  Similarly, under the  adultery law in India  (Section 497 of the Indian Penal Code, until overturned by the  Supreme Court  in 2018) it was a criminal offense for a man to have consensual sexual intercourse with a married woman, without the consent of her husband (no party was criminally punished in case of adultery between a married man and an unmarried woman).


In Southwest Asia, adultery has attracted severe  sanctions , including the  death penalty . In some places, such as  Saudi Arabia , the method of punishment for adultery is  stoning to death . Proving adultery under Muslim law can be a very difficult task as it requires the accuser to produce four eyewitnesses to the act of sexual intercourse, each of whom should have a good reputation for truthfulness and honesty. The criminal standards do not apply in the application of social and family consequences of adultery, where the standards of proof are not as exacting. [ 14 ] [ 15 ]   Sandra Mackey , author of  The Saudis: Inside the Desert Kingdom , stated in 1987 that in Saudi Arabia, "unlike the tribal rights of a father to put to death a daughter who has violated her chastity, death sentences under Koranic law [for adultery] are extremely rare." [ 16 ]


In regions of Iraq and Syria under ISIL, there have been reports of floggings as well as execution of people who engaged in adultery. The method of execution was typically by  stoning . [ 17 ]  ISIL would not merely oppose adultery but also oppose behavior that from their point of view could lead to adultery, such as women not being covered, people of the opposite sex socializing with one another, or even female mannequins in store windows. [ 18 ]


In  China , punishments for adultery were differentiated based on gender of the spouse until 1935. [ 19 ]  Adultery is no longer a crime in the  People's Republic of China , but is a  ground for divorce . [ 20 ]  It is illegal to commit adultery with the spouse of a servicemember in the  People's Liberation Army . [ 21 ] [ 22 ]


In  Taiwan , adultery was a criminal offense before 2020. [ 23 ] [ 24 ]  The law was challenged in 2002 when it was upheld by the  Constitutional Court . [ 25 ]  Arguments were heard again by the court in March 2020, [ 26 ] [ 27 ]  and the court ruled the law unconstitutional on 29 May 2020. [ 28 ]  Twelve of fifteen justices issued a concurring opinion, two others concurred in part, and one dissented. [ 29 ] [ 30 ]  The  Legislative Yuan  amended the  Criminal Code  [ zh ]  on 31 May 2021, removing the article criminalizing adultery entirely. [ 31 ]


During  Qing rule in Taiwan  (1683 to 1895), the husband or his relatives could bring charges. The standard sentence was ninety lashes for each of the accused. The woman could be sold or divorced. The matter could be settled out of court, with bodily harm to the accused or assorted punishments affecting his social standing. Under  Japanese rule , only the husband could bring charges. The accused could be sentenced to two years imprisonment.  Wife selling  became illegal, although private settlements still occurred. [ 19 ]


On 27 September 2018, the  Supreme Court of India  ruled Section 497 of the  Indian Penal Code , the law which criminalized adultery, as unconstitutional. [ 32 ] [ 33 ] [ 34 ]  Before 2018, adultery was defined as sex between a man and a woman without the consent of the woman's husband. [ 35 ]  The man was prosecutable and could be sentenced for up to five years (even if he himself was unmarried) whereas the married woman couldn't be jailed. [ 36 ]  Men have called the law  gender discrimination  in that women cannot be prosecuted for adultery [ 37 ]  and the National Commission of Women has criticized the British era law of being anti-feminist as it treats women as the property of their husbands and has consequently recommended deletion of the law or reducing it to a civil offense. [ 38 ]  Extramarital sex without the consent of one's partner can be a valid grounds for monetary penalty on government employees, as ruled by the Central Administrative Tribunal. [ 39 ]


Adultery was a crime in  Japan  until 1947. [ 40 ]


In 2015,  South Korea's Constitutional Court  overturned the country's law against adultery. [ 41 ]  Previously, adultery was criminalized in 1953, and violators were subject to two years in prison, with the aim of protecting women from divorce. The law was overturned because the court found that adultery is a private matter in which the state should not intervene. [ 42 ] [ 43 ] [ 44 ]


In  Pakistan , adultery is a crime under the  Hudood Ordinance , promulgated in 1979. The Ordinance sets a maximum penalty of  death . The Ordinance has been particularly controversial because it requires a woman making an accusation of  rape  to provide extremely strong evidence to avoid being charged with adultery herself. A conviction for rape is only possible with evidence from no fewer than four witnesses. In recent years high-profile rape cases in Pakistan have given the Ordinance more exposure than similar laws in other countries. [ 45 ]  Similar laws exist in some other Muslim countries, such as  Saudi Arabia  and  Brunei .


Adultery is a crime in the  Philippines . [ 46 ]  In the Philippines, the law differentiates based on the gender of the spouse. A wife can be charged with adultery, while a husband can only be charged with the related crime of concubinage, which is more loosely defined (it requires either keeping the mistress in the family home, or cohabiting with her, or having sexual relations under scandalous circumstances). [ 47 ]  There are currently proposals to decriminalize adultery in the Philippines. [ 48 ]


Adultery is no longer a crime in any European country.


Adultery in English law  was not a criminal offence in secular law from the later twelfth century until the seventeenth century. It was punishable under ecclesiastical law from the twelfth century until jurisdiction over adultery by ecclesiastical courts in England and Wales was abolished in England and Wales (and some British territories of the British Empire) by the  Matrimonial Causes Act 1857 . However, in English and Welsh common law of  tort  it was possible from the early seventeenth century for a spouse to prosecute an adulterer for damages on the grounds of  loss of consortium  until the  Law Reform (Miscellaneous Provisions) Act 1970 . Adultery was also illegal under secular statute law for the decade in which the  Commonwealth (Adultery) Act (1650)  was in force. [ 49 ] [ 50 ]


Among the last European countries to decriminalise adultery were  Italy  (1969),  West Germany  (1969),  Malta  (1973),  Luxembourg  (1974),  France  (1975),  Spain  (1978),  Portugal  (1982),  Greece  (1983),  Belgium  (1987),  Switzerland  (1989), and  Austria  (1997). [ 51 ] [ 52 ] [ 53 ] [ 54 ] [ 55 ] [ 56 ] [ 57 ] [ 58 ]


In  Romania  adultery was a crime until 2006, [ 59 ]  though the crime of adultery had a narrow definition, excluding situations where the other spouse encouraged the act or when the act happened at a time the couple was living separate and apart; [ 60 ]  and in practice prosecutions were extremely rare. [ 61 ]


In  Turkey , adultery laws were held to be invalid in 1996/1998 because the law was deemed discriminatory as it differentiated between women and men. In 2004, there were proposals to introduce a gender-neutral adultery law. The plans were dropped, and it has been suggested that the objections from the European Union played a role. [ 53 ] [ 62 ] [ 63 ]


Before the 20th century, adultery was often punished harshly. In Scandinavia, in the 17th century, adultery and bigamy were subject to the  death penalty , although few people were actually executed. [ 64 ]  Examples of women who have been executed for adultery in Medieval and Early Modern Europe include  Maria of Brabant, Duchess of Bavaria  (in 1256),  Agnese Visconti  (in 1391),  Beatrice Lascaris di Tenda  (in 1418),  Anne Boleyn  (in 1536), and  Catherine Howard  (in 1542). The enforcement of adultery laws varied by jurisdiction. In England, the last execution for adultery is believed to have taken place in 1654, when a woman named Susan Bounty was  hanged . [ 65 ]


The  European Court of Human Rights  (ECHR) has had the opportunity to rule in recent years on several cases involving the legitimacy of firing a person from their job due to adultery. These cases dealt with people working for religious organizations and raised the question of the balancing of the right of a person to respect for their private life (recognized in the EU) and the right of religious communities to be protected against undue interference by the State (recognized also in the EU). These situations must be analyzed with regard to their specific circumstances, in each case. The ECtHR had ruled both in favor of the religious organization (in the case of Obst) and in favor of the fired person (in the case of Schüth). [ 66 ]


Until the 1990s, most Latin American countries had laws against adultery. Adultery has been decriminalized in most of these countries, including  Paraguay  (1990), [ 67 ]   Chile  (1994), [ 68 ]   Argentina  (1995), [ 69 ]   Nicaragua  (1996), [ 70 ]   Dominican Republic  (1997), [ 71 ]   Brazil  (2005), [ 72 ]  and  Haiti  (2005). [ 73 ]  In some countries, adultery laws have been struck down by courts on the ground that they discriminated against women, such as  Guatemala  (1996), where the Guatemalan Constitutional Court struck down the adultery law based both on the Constitution's  gender equality  clause and on human rights treaties including CEDAW; [ 74 ]  and  Venezuela  in 2016. [ 75 ]  The adultery law of the Federal Criminal Code of  Mexico  was repealed in 2011. [ 76 ] [ 77 ]


Adultery is not a crime in Australia. Under federal law enacted in 1994, sexual conduct between consenting adults (18 years of age or older) is their private matter throughout Australia, [ 78 ]  irrespective of marital status. Australian states and territories had previously repealed their respective adultery criminal laws. Australia changed to  no-fault divorce  in 1975, abolishing adultery as a ground for divorce.


Adultery is not a crime in Canada. It has never been defined as a criminal offence within the  Criminal Code , which was enacted in 1892, nor is it considered an offence at common law. [ 79 ]


The United States is one of few  industrialized countries  to have laws criminalizing adultery. [ 80 ]  In the United States, laws vary from state to state. Until the mid-20th century, most U.S. states (especially Southern and Northeastern states) had laws against  fornication , adultery or  cohabitation . These laws have gradually been abolished or struck down by courts as unconstitutional. [ 81 ] [ 82 ] [ 83 ]


State criminal laws against adultery are rarely enforced. Federal appeals courts have ruled inconsistently as to whether these laws are unconstitutional (especially after the 2003  Supreme Court  decision  Lawrence v. Texas ) and as of 2019 the Supreme Court has not ruled directly on the issue. [ 84 ] [ 85 ]


As of 22 November 2024, adultery remains a crime in 16 states and the  Commonwealth of Puerto Rico  but prosecutions are rare. [ 86 ] [ 87 ] [ 88 ]   Pennsylvania  abolished its fornication and adultery laws in 1973. [ 89 ]  States which have decriminalised adultery in recent years include  West Virginia  (2010), [ 90 ]   Colorado  (2013), [ 91 ]   New Hampshire  (2014), [ 87 ] [ 92 ]   Massachusetts  (2018), [ 93 ]   Utah  (2019), [ 94 ]   Idaho  (2022), [ 95 ]   Minnesota  (2023), [ 96 ]  and  New York  (2024). [ 97 ]  The  District of Columbia  repealed its adultery law in 2003. [ 98 ] [ 99 ]  When passing the  District of Columbia Organic Act of 1801 , the  6th United States Congress  extended all of the criminal laws of  Maryland  and  Virginia  to the respective territory within the District that each state had ceded to the federal government under  Article I, Section VIII , [ 100 ]  and adultery had been an indictable offense in Maryland since the passage of a  provincial law  in 1715. [ 101 ]


The last conviction for adultery in Massachusetts was in 1983 and held that the statute was constitutional and that "no fundamental personal privacy right implicit in the concept of ordered liberty guaranteed by the United States Constitution bars the criminal prosecution of such persons [adulterers]." [ 102 ]


Today, adultery laws are mostly found in the  conservative   southern states .


In general, 3 US states criminalize it as a  felony  (Oklahoma, Michigan, and Wisconsin) and 13 states along with Puerto Rico criminalize it as a  misdemeanor . Punishments range from as little as a $10 fine in Maryland (despite being technically a criminal offense, not a civil one) to a fine of up to $10,000 and jail time of up to 3.5 years in Wisconsin and a fine of up to $5,000 and jail time of up to 5 years in Michigan.


List of the statutes:


2 of these statutes (of Mississippi and North Carolina) refer to fornication as well and thus also by definition ban any extramarital sex altogether.


1 of these statutes (of Michigan) considers cohabitation between ex-spouses after their divorce as falling under the crime of adultery.


Below is the list of the specific anti-fornication statutes (in states where there's an offense of fornication and where it's a separate offence):


Below is the list of the specific anti-cohabitation statutes (in states where there's an offense of cohabitation and where it's a separate offence):


In the  U.S. military , adultery is a potential  court-martial  offense, falling under the  General article  (Art. 134). [ 103 ]  The  Manual for Courts-Martial  defines (para. 99) "Extramarital sexual conduct" as being:
 "Elements.(1) That  the  accused  wrongfully  engaged  in extramarital  conduct  as  described  in  subparagraph  c.(2) with a certain person; (2) That, at the time, the accused knew that the accused or the other person was married to someone else; and (3) That, under the circumstances, the conduct of the accused was either: (i) to the prejudice of good order and discipline in the armed forces; (ii) was of a nature to bring discredit upon the armed forces; or (iii) to the prejudice of good order and discipline in  the armed forces and of a nature to bring discredit upon the armed forces" . [ 104 ]  As such, extramarital sex is not  automatically an offense, it must be conducted under such circumstances that it is prejudicial to the armed forces. The law on adultery was revised in 2019 in order to include same-sex encounters in the offense. [ 105 ]


The enforceability of adultery laws in the United States is unclear following Supreme Court decisions since 1965 relating to privacy and sexual intimacy of consenting adults. [ 106 ]  However, occasional prosecutions do occur. [ 107 ]


Six U.S. states ( Hawaii ,  North Carolina ,  Mississippi ,  New Mexico ,  South Dakota , and Utah) allow the possibility of the  tort  action of  alienation of affections  (brought by a deserted spouse against a third party alleged to be responsible for the failure of the marriage). [ 108 ] [ 109 ]  In a highly publicized case in 2010, a woman in North Carolina won a $9 million suit against her husband's  mistress . [ 110 ] [ 111 ]


Laws against adultery in  colonial America  were very harsh. Despite this, there is only one known execution for adultery in American history: it occurred in the  Colony of Massachusetts  in 1643, when the married 18 year old Mary Latham [ 112 ]  and her extramarital lover James Britton were executed. [ 113 ] [ 114 ]


Laws against adultery have been named as invasive and incompatible with principles of  limited government  (see Dennis J. Baker, The Right Not to be Criminalized: Demarcating Criminal Law's Authority (Ashgate) chapter 2). Much of the criticism comes from  libertarianism , the consensus among whose adherents is that government must not intrude into daily personal lives and that such disputes are to be settled privately rather than  prosecuted  and  penalized  by  public entities . It is also argued that adultery laws are rooted in religious doctrines; which should not be the case for laws in a  secular state .


Opponents of adultery laws regard them as painfully archaic, believing they represent sanctions reminiscent of nineteenth-century novels. They further object to the legislation of morality, especially a morality so steeped in religious doctrine. Support for the preservation of the adultery laws comes from religious groups and from political parties who feel quite independent of morality, that the government has reason to concern itself with the consensual sexual activity of its citizens … The crucial question is: when, if ever, is the government justified to interfere in consensual bedroom affairs? [ 115 ]


Opponents of adultery laws argue that these laws maintain social norms which justify violence, discrimination and oppression of women; in the form of state sanctioned forms of violence such as  stoning ,  flogging  or  hanging  for adultery; or in the form of individual acts of violence committed against women by husbands or relatives, such as  honor killings ,  crimes of passion , and beatings. [ 74 ] [ 116 ]   UN Women  has called for the decriminalization of adultery. [ 116 ]  A Joint Statement by the United Nations Working Group on discrimination against women in law and in practice in 2012, stated: [ 74 ]


The United Nations Working Group on discrimination against women in law and in practice is deeply concerned at the criminalization and penalization of adultery whose enforcement leads to discrimination and  violence against women .


Concerns exist that the existence of "adultery" as a criminal offense (and even in family law) can affect the criminal justice process in cases of domestic assaults and killings, in particular by mitigating  murder  to  manslaughter , [ 117 ]  or otherwise proving for partial or complete defenses in case of violence. These concerns have been officially raised by the Council of Europe and the UN in recent years. The  Council of Europe Recommendation Rec(2002)5 of the Committee of Ministers to member states on the protection of women against violence  states that member states should: (...) "57. preclude adultery as an excuse for violence within the family". [ 118 ]   UN Women  has also stated in regard to the defense of  provocation  and other similar defenses that "laws should clearly state that these defenses do not include or apply to crimes of 'honour', adultery, or domestic assault or murder." [ 119 ]


An argument against the criminal status of adultery is that the resources of the law enforcement are limited, and that they should be used carefully; by investing them in the investigation and prosecution of adultery (which is very difficult) the curbing of serious violent crimes may suffer. [ 120 ]


Human rights organizations have stated that legislation on sexual crimes must be based on  consent , and must recognize consent as central, and not trivialize its importance; doing otherwise can lead to legal, social or ethical abuses. Amnesty International, when condemning stoning legislation that targets adultery, among other acts, has referred to "acts which should never be criminalized in the first place, including consensual sexual relations between adults". [ 121 ]  Salil Shetty, Amnesty International's Secretary General, said: "It is unbelievable that in the twenty-first century some countries are condoning  child marriage  and  marital rape  while others are outlawing abortion, sex outside marriage and same-sex sexual activity – even punishable by death." [ 122 ]  The  My Body My Rights  campaign has condemned state control over individual sexual and reproductive decisions; stating "All over the world, people are coerced, criminalized and discriminated against, simply for making choices about their bodies and their lives". [ 123 ]


Air sex  is a performance activity invented in  Japan ; clothed men and women simulate  sexual activity  with an invisible partner, often in an exaggerated manner, set to music, and in a competition before an audience. This is somewhat akin to playing  air guitar , explaining the name. The creator,  J-Taro Sugisaku , says that it was invented in  Tokyo  in 2006 by a group of bored men without girlfriends.


A report about the phenomenon in the Japanese magazine  Weekly Playboy  in 2006 was picked up by the English language web site  Mainichi Daily News . [ 1 ]  A video of the air sex "world championship" was uploaded to  YouTube  in January 2007. [ 2 ]  This was followed by a segment of the  BBC Three  documentary show  Japanorama  in March 2007, [ 3 ]  subsequently uploaded to YouTube and flagged as "inappropriate for some users".


These videos led to coverage in the  blogosphere . [ 4 ]  The  Japanorama  video was shown in May 2007 at the  JACON 2007  convention in  Orlando, Florida , and a spontaneous air sex competition ensued, footage of which also found its way to YouTube. [ 5 ]


In late January and early February 2007, a group of American black male teenagers calling themselves "Peer Pressure" produced two videos showing air sex set to music, published on YouTube under the user name "amp6".  Fleshbot  called these "The Best Air Sex Video of All Time". [ 6 ]


Since August 2007, The  Alamo Drafthouse  has been holding bimonthly Air Sex competitions in the US. [ 7 ]   In June 2009 The Alamo Drafthouse toured the country on the Air Sex World Championships tour crowning Air Sex Champions in 14 cities. Later that October the first ever world champion was crowned when Shanghai Slammer from Los Angeles out-performed every other city champion. The tour was hosted by comedian  Chris Trew . In October 2010 the group was scheduled to tour once more.  Photos are posted on the Alamo Drafthouse Flickr page. [ 8 ] [ 9 ]


Alcohol and sex  deals with the effects of the consumption of  alcohol  on  sexual behavior . [ 2 ]  The effects of alcohol are balanced between its suppressive effects on sexual physiology, which will decrease sexual activity, and its suppression of  sexual inhibitions . [ 3 ]  A large portion of  sexual assaults  involve alcohol consumption by the perpetrator, victim, or both. [ 4 ]


Alcohol is a depressant. After consumption, alcohol causes the body's systems to slow down. Often, feelings of  drunkenness  are associated with elation and happiness but other feelings of anger or depression can arise. Balance, judgment, and coordination are also negatively affected. One of the most significant short term side effects of alcohol is reduced inhibition. Reduced inhibitions can lead to an increase in sexual behavior. [ 3 ]


Low to moderate alcohol consumption is shown to have protective effect for men's erectile function. Several reviews and  meta-analyses  of existing literature show that low to moderate alcohol consumption significantly decreases  erectile dysfunction  risk. [ 5 ] [ 6 ] [ 7 ] [ 8 ]


Men's sexual behaviors can be affected dramatically by high alcohol consumption. Both chronic and acute alcohol consumption have been shown in most studies
 [ 9 ] [ 10 ] [ 11 ]  (but not all [ 12 ] ) to inhibit  testosterone  production in the testes. This is believed to be caused by the metabolism of alcohol reducing the  NAD + / NADH  ratio both in the liver and the testes; since the synthesis of testosterone requires NAD + , this tends to reduce testosterone production. [ 13 ] [ 14 ]


As testosterone is critical for libido and physical arousal, alcohol tends to have deleterious effects on male sexual performance. Studies have been conducted that indicate increasing levels of alcohol intoxication produce a significant degradation in male masturbatory effectiveness (MME). This degradation was measured by measuring  blood alcohol concentration  (BAC) and ejaculation latency. [ 15 ]  Alcohol intoxication can decrease sexual arousal, decrease pleasureability and intensity of  orgasm , and increase difficulty in attaining orgasm. [ 15 ]


In women, the effects of alcohol on libido in the literature are mixed. Some women report that alcohol increases sexual arousal and desire, however, some studies show alcohol lowers the physiological signs of arousal. [ 16 ]  A 2016 study found that alcohol negatively affected how positive the sexual experience was in both men and women. [ 17 ]  Studies have shown that acute alcohol consumption tends to cause increased levels of testosterone and  estradiol . [ 18 ] [ 19 ]  Since testosterone controls in part the strength of libido in women, this could be a physiological cause for an increased interest in sex. Also, because women have a higher percentage of body fat and less water in their bodies, alcohol can have a quicker, more severe impact. Women's bodies take longer to process alcohol; more precisely, a woman's body often takes one-third longer to eliminate the substance. [ 20 ]


Sexual behavior in women under the influence of alcohol is also different from men. Studies have shown that increased BAC is associated with longer orgasmic latencies and decreased intensity of orgasm. [ 16 ]  Some women report a greater  sexual arousal  with increased alcohol consumption as well as increased sensations of pleasure during orgasm. Because ejaculatory response is visual and can more easily be measured in males, orgasmic response must be measured more intimately. In studies of the female orgasm under the influence of alcohol, orgasmic latencies were measured using a  vaginal photoplethysmograph , which essentially measures vaginal blood volume. [ 16 ]


Psychologically, alcohol has also played a role in sexual behavior. It has been reported that women who were intoxicated believed they were more sexually aroused than before consumption of alcohol. [ 16 ]  This psychological effect contrasts with the physiological effects measured, but refers back to the loss of inhibitions because of alcohol. Often, alcohol can influence the capacity for a woman to feel more relaxed and in turn, be more sexual. Alcohol may be considered by some women to be a sexual disinhibitor. [ 16 ]


Some studies have made a connection between  hookup culture  and substance use. [ 21 ]  Most students said that their hookups occurred after drinking alcohol. [ 21 ] [ 22 ] [ 23 ]  Frietas stated that in her study, the relationships between drinking and the party scene and between alcohol and hookup culture were "impossible to miss". [ 24 ]


Studies suggest that the degree of  alcoholic intoxication  in young people directly correlates with the level of risky behavior, [ 25 ]  such as engaging in  multiple sex partners . [ 26 ]


In 2018, the first study of its kind, found that  alcohol and caffeinated   energy drinks  is linked with casual, risky sex among college-age adults. [ 27 ]


Alcohol intoxication is associated with an increased risk that people will become involved in  risky sexual behaviors , such as unprotected sex. [ 15 ]  Both men, [ 28 ]  and women, [ 29 ]  reported higher intentions to  avoid using a condom  when they were intoxicated by alcohol.


Coitus interruptus , also known as withdrawal, pulling out or the pull-out method, is a method of  birth control  during penetrative  sexual intercourse , whereby the  penis  is withdrawn from a  vagina  or  anus  prior to  ejaculation  so that the ejaculate ( semen ) may be directed away in an effort to avoid  insemination . [ 30 ] [ 31 ]  Coitus interruptus carries a risk of  STIs  and  unintended pregnancy . This risk is especially high during  alcohol intoxication  because lowered  sexual inhibition  can make it difficult to withdraw in time.


Women with  unintended pregnancies  are more likely to  smoke tobacco , [ 32 ]  drink alcohol during pregnancy, [ 33 ] [ 34 ]  and binge drink during pregnancy, [ 32 ]  which results in poorer health outcomes. [ 33 ]  (See also:  fetal alcohol spectrum disorder )


Rape is any sexual activity that occurs without the freely given  consent  of one of the parties involved. This includes  alcohol-facilitated sexual assault  which is considered rape in most if not all jurisdictions, [ 35 ]  or  non-consensual condom removal  which is criminalized in some countries (see the map below).


A 2008 study found that rapists typically consumed relatively high amounts of alcohol and infrequently used condoms during assaults, which was linked to a significant increase in STI transmission. [ 36 ]  This also increases the risk of  pregnancy from rape  for female victims. Some people turn to drugs or alcohol to cope with emotional trauma after a rape; use of these during pregnancy can harm the fetus. [ 37 ]


One of the most common  date rape drugs  is alcohol, [ 39 ] [ 40 ] [ 41 ]  administered either surreptitiously [ 42 ]  or consumed voluntarily, [ 39 ]  rendering the victim unable to make informed decisions or give consent. The perpetrator then facilitates  sexual assault  or  rape , a crime known as alcohol- or  drug-facilitated sexual assault  (DFSA). [ 43 ] [ 35 ] [ 44 ]  Many perpetrators use alcohol because their victims often drink it willingly, and can be encouraged to drink enough to lose inhibitions or consciousness. [ 45 ]  However, sex with an unconscious victim is considered rape in most if not all jurisdictions, and some assailants have committed "rapes of convenience" whereby they have assaulted a victim after he or she had become unconscious from drinking too much. [ 46 ]  The risk of individuals either experiencing or perpetrating  sexual violence  and  risky sexual behavior  increases with  alcohol abuse , [ 47 ]  and by the consumption of  caffeinated alcoholic drinks . [ 48 ] [ 49 ]


Non-consensual condom removal , or "stealthing", [ 50 ]  is the practice of a person removing a  condom  during  sexual intercourse  without consent, when their sex partner has only  consented  to condom-protected sex. [ 51 ] [ 52 ]  Purposefully damaging a condom before or during intercourse may also be referred to as stealthing, [ 53 ]  regardless of who damaged the condom.


Consuming alcohol can be risky in sexual situations. It can impair judgment and make it difficult for both people to give or receive informed  sexual consent . However, a history of sexual aggression and  alcohol intoxication  are factors associated with an increased risk of men employing non-consensual condom removal and engaging in sexually aggressive behavior with female partners. [ 54 ] [ 55 ]


The use of alcohol is a documented factor in  wartime sexual violence .


For example,  rape during the liberation of Serbia  was committed by Soviet  Red Army  soldiers against women during their advance to Berlin in late 1944 and early 1945 during  World War II . Serbian journalist Vuk Perišić said about the rapes: "The rapes were extremely brutal, under the influence of alcohol and usually by a group of soldiers. The Soviet soldiers did not pay attention to the fact that Serbia was their ally, and there is no doubt that the Soviet high command tacitly approved the rape." [ 56 ]


While there wasn't a codified international law specifically prohibiting rape during World War II,  customary international law  principles already existed that condemned violence against civilians. These principles formed the basis for the development of more explicit laws after the war, [ 57 ]  including the  Nuremberg Principles  established in 1950.


A study published in 2003 supported the beer goggles hypothesis; however, it also found that another explanation is that regular drinkers tend to have personality traits that mean they find people more attractive, whether or not they are under the influence of alcohol at the time. [ 58 ]  A 2009 study showed that while men found adult women (who were wearing  makeup ) more attractive after consuming alcohol, the alcohol did not interfere with their ability to determine a woman's age. [ 59 ]


A 2021 study found that bar patrons rated themselves as more attractive towards the end of the night, regardless of their level of intoxication, and that this effect had more to do with motivations to attract a mate. The "closing time effect" was tested in Danish bars, with researchers separating responses based on whether bar patrons had filled out their survey in the afternoon, evening, or night, and finding that people attending the bar at night rated themselves as more attractive than earlier visitors. [ 60 ]


A  bed  is an item of  furniture  that is used as a place to  sleep ,  rest , and  relax . [ 1 ] [ 2 ]


Most modern beds consist of a soft, cushioned  mattress  on a  bed frame . The mattress rests either on a solid  base , often wood slats, or a sprung base. Many beds include a  box spring inner-sprung base , which is a large mattress-sized box containing wood and springs that provide additional support and suspension for the mattress. Beds are available in many sizes, ranging from infant-sized  bassinets  and  cribs , to small beds for a single person or adult, to large queen and king-size beds designed for two people. While most beds are single mattresses on a fixed frame, there are other varieties, such as the  murphy bed , which folds into a wall, the  sofa bed , which folds out of a sofa, the  trundle bed , which is stored under a low, twin-sized bed and can be rolled out to create a larger sleeping area, and the  bunk bed , which provides two mattresses on two tiers as well as a ladder to access the upper tier. Temporary beds include the inflatable  air mattress  and the folding  camp cot . Some beds contain neither a padded mattress nor a bed frame, such as the  hammock . Other beds are made specifically  for animals .


Beds may have a  headboard  for resting against, and may have side rails and footboards. "Headboard only" beds may incorporate a "dust ruffle", "bed skirt", or "valance sheet" to hide the bed frame. To support the head, a  pillow  made of a soft, padded material is usually placed on the top of the mattress. Some form of covering  blanket  is often used to insulate the sleeper, often  bed sheets , a  quilt , or a  duvet , collectively referred to as  bedding . Bedding is the removable non-furniture portion of a bed, which enables these components to be washed or aired out.


In Europe, mattresses were stuffed with straw, chaff, animal hair (for instance  horsehair , used for its resilience), coarse wool, or  down feathers , and stacked, softest topmost. This pile of mattresses, and the sheets, blanket, and pillows, was what early Europeans called a "bed"; it might be packed away during the day (a usage which survives in words like  featherbed ). The  bedframe , even when present, supported the bed, but was not considered part of it. [ 3 ] : 674–5 vol1    Later innovations  made bedframes more portable, and increased their importance. [ 3 ] : 481vol3  : 674vol1  : 675–6 vol1


In August 2020 scientists reported the discovery of the oldest grass bedding from  at least 200,000 years ago , much older than the oldest previously known bedding. They speculate that  insect-repellent plants  and ash layers, sometimes due to burned older grass beddings, found beneath the bedding have been used for a dirt-free, insulated base and to keep away  arthropods . [ 4 ] [ 5 ] [ 6 ]


Early beds were little more than piles of  straw  or some other natural material (e.g. a heap of palm leaves, animal skins, or dried  bracken ). [ 7 ]   An important change was raising them off the ground, to avoid drafts, dirt, and pests. [ citation needed ]  In the  Miocene period , lasting from twenty-three to five million years ago, before the emergence of humans, apes began creating beds composed of a sleeping platform including a wooden  pillow . [ 8 ]


Bedding dated around to 3600 BC was discovered in  Sibudu Cave , South Africa. [ 9 ]  The bedding consists of  sedge  and other  monocotyledons  topped with the leaves of  Cryptocarya woodii . [ 9 ]


Beds found in a preserved northern Scottish village, which were raised boxes made of stone and likely topped with comfortable fillers, were dated to between 3200 BC and 2200 BC. [ 10 ]


The  Odyssey , an  ancient Greek   epic poem , describes the bed of its protagonist,  Odysseus , and explains that he crafted the bed for himself and his wife,  Penelope , out of a huge  olive tree  trunk that used to grow on the spot. [ 11 ]  The poem's author,  Homer , also mentions the inlaying of the woodwork of the bed with  gold ,  silver , and  ivory . [ 11 ]


Ancient Roman   mattresses  were stuffed with  reeds ,  hay , or  wool .  Feathers  were used towards the end of the  Republic , when custom demanded luxury. Small cushions were placed at the head and sometimes at the back. The bedsteads were high and could only be ascended by the help of steps. They were often arranged for two people, and had a board or railing at the back, as well as the raised portion at the head. The counterpanes were sometimes very costly, generally  purple  embroidered with figures in  gold ; and rich hangings fell to the ground masking the front. The bedsteads themselves were often of bronze inlaid with silver, and  Elagabalus  had one of solid silver. In the walls of some houses at  Pompeii  bed niches are found which were probably closed by curtains or sliding partitions.  Ancient Romans  had various kinds of beds for repose. These included:


The Greeks and Romans were also having their meals in bed. They would recline on one side and reach out to pick up food from a nearby table. [ 14 ]


The  Egyptians  had high bedsteads which were ascended by steps, with bolsters or  pillows , and  curtains  to hang around. [ 15 ]  The elite of Egyptian society such as its pharaohs and queens even had beds made of wood, sometimes gilded. Often there was a head-rest as well, semi-cylindrical and made of  stone ,  wood , or  metal . [ 16 ]  Ancient Assyrians,  Medes , and  Persians  had beds of a similar kind, and frequently decorated their furniture with inlays or appliques of metal,  mother-of-pearl , and  ivory .


In the early  Middle Ages  they laid  carpets  on the floor or on a  bench  against the wall, placed upon them were mattresses stuffed with  feathers ,  wool , or  hair , and used skins as a covering. Curtains were hung from the ceiling or from an  iron  arm projecting from the wall. [ 18 ]  They appear to have generally lain  naked  in bed, wrapping themselves in large  linen  sheets which were stretched over the cushions.


In the 12th century, luxury increased and bedsteads were made of wood much decorated with inlaid, carved, and painted ornamentation. They also used folding beds, which served as couches by day and had cushions covered with silk laid upon  leather . At night a linen sheet was spread and pillows placed, while silk-covered skins served as coverlets. The  Carolingian   manuscripts  show metal bedsteads much higher at the head than at the feet, and this shape continued in use until the 13th century in France, many cushions being added to raise the body to a sloping position. In 12th-century manuscripts, the bedsteads appear much richer, with inlays, carving, and painting, and with embroidered coverlets and mattresses in harmony. Curtains were hung above the bed and a small hanging  lamp  is often shown. [ citation needed ]


In the 14th century the woodwork became of less importance, generally being entirely covered by hangings of rich materials.  Silk ,  velvet , and even cloth of  gold  were frequently used. Inventories from the beginning of the 14th century give details of these hangings lined with  fur  and richly embroidered. It was then that the  Four poster bed  (also known as a  tester bed ) made its first appearance, the bed being slung from the ceiling or fastened to the walls, a form which developed later into a room within a room, shut in by double curtains, sometimes even to exclude all drafts. The space between the bed and the wall was called the  ruelle , and very intimate friends were received there. The 14th century was also the time when feather beds became highly prized possessions. [ 18 ]  Beds in aristocratic residences can be distinguished by enclosed curtains, these beds would have mattresses and pillows that were filled with feathers. Sheets were made of linen and blankets of wool. Rails attached to the beds would be for hanging clothes or to hold candles. In less wealthy houses, the bed would be made of three planks and a mattress made of dried heather or fern, they would sleep with a single sheet and an old blanket. [ 19 ]


In the 15th century beds became very large, reaching 7 to 8 feet (2.1 to 2.4 m) by 6 to 7 feet (1.8 to 2.1 m). The mattresses were often filled with pea-shucks, straw, or feathers. At this time great personages were in the habit of carrying most of their property about with them, including beds and  bed hangings , and for this reason the bedsteads were for the most part mere frameworks to be covered up; but about the beginning of the 16th century bedsteads were made lighter and more decorative, since the lords remained in the same place for longer periods. [ citation needed ]


In the 17th century, which has been called "the century of magnificent beds", the style  à la duchesse , with  tester  and curtains only at the head, replaced the more enclosed beds in France, though they lasted much longer in England.  Louis XIV  had an enormous number of sumptuous beds, as many as 413 being described in the inventories of his palaces. Some of them had embroideries enriched with  pearls , and figures on a silver or golden ground. The great bed at  Versailles  had crimson velvet curtains on which "The Triumph of Venus" was embroidered. So much gold was used that the  velvet  scarcely showed.


In the 18th century feather pillows were first used as coverings in Germany, which in the fashions of the bed and the curious etiquette connected with the bedchamber followed France for the most part. The beds were  a la duchesse , but in France itself there was great variety both of name and shape. The custom of the " bed of justice " upon which the  king of France  reclined when he was present in  parliament , the  princes  being seated, the great officials standing, and the lesser officials kneeling, was held to denote the royal power even more than the  throne .


Louis XI  is credited with its first use and the custom lasted until the end of the  monarchy . In the  chambre de parade , where the ceremonial bed was placed, certain persons, such as  ambassadors  or great  lords , whom it was desired to honour, were received in a more intimate fashion than the crowd of  courtiers . At  Versailles  women received their friends in their beds, both before and after  childbirth , during periods of  mourning , and even directly after  marriage —in fact in any circumstances which were thought deserving of congratulation or condolence. During the 17th century this curious custom became general, perhaps to avoid the tiresome details of etiquette. Portable beds were used in high society in France until the end of the  Ancien Régime . The earliest of which mention has been found belonged to  Charles the Bold . They had curtains over a light framework, and were in their way as fine as the stationary beds.


Iron beds appear in the 18th century; the  advertisements  declare them as free from the  insects  which sometimes infested wooden bedsteads. Elsewhere, there was also the closed bed with sliding or folding shutters, and in England—where beds were commonly quite simple in form—the  four poster  was the usual citizen's bed until the middle of the 19th century.


Bed sizes vary considerably around the world, with most countries having their own standards and terminology.


One of the largest beds in the world is the  Great Bed of Ware , made in about 1580. It is 3.26 metres (10.7 ft) wide, 3.38 metres (11.1 ft) long. The bed is mentioned by  Shakespeare  in  Twelfth Night . It is now in the  Victoria and Albert Museum  (V&A) in  London . Another bed in the V&A is the  Golden Bed  created by  William Burges  in 1879. [ 20 ]


In 1882,  Nawab of Bahawalpur   Sadiq Muhammad Khan Abassi IV  had a bed made of dark wood ornamented with 290 kilograms (640 lb) of sterling silver. At each corner of the bed there was a life-sized bronze statue of a naked woman holding a fan. When the Nawab lay on the bed, his weight started a mechanism that made the women wave their fans and started a music box playing selections from  Gounod's Faust . [ 21 ]


In 1865, a convertible bed in the form of an  upright piano  was available, which could provide home entertainment while saving space. [ 22 ]


There are many varieties of beds:


Bed frames , also called bed steads, are made of wood or metal. The frame is made up of head, foot, and side rails. For heavy duty or larger frames (such as for queen- and king-sized beds), the bed frame also includes a center support rail. The rails are assembled to create a box for the mattress or mattress/box spring to sit on.


Although not truly parts of a bed frame, headboards, footboards, and bed rails can be included in the definition.  Headboards  and footboards can be wood or metal. They can be stained, painted, or covered in fabric or leather.


Bed rails are made of wood or metal and are attached to a headboard and footboard. Wooden slats are placed perpendicular to the bed rails to support the mattress/mattress box spring. Bed rails and frames are often attached to the bed post using knock-down fittings. [ 25 ] [ 26 ]  A knock-down fitting enables the bed to be easily dismantled for removal. Primary knock-down fittings for bed rails are as follows:


Safety rails, or  cot sides , can be added to the sides of a bed (normally a child or elderly person's bed) to stop anyone falling out of the sides of the bed. [ 27 ]  A safety rail is normally a piece of wood that attaches to the side rails, on one or both sides of the bed. They are made so that they can be easily removed when no longer required.


The  breasts  are two prominences located on the upper  ventral  region of the  torso  among humans and other  primates . Both sexes develop breasts from the same  embryological  tissues. The relative size and development of the breasts is a major  secondary sex distinction  between females and males. There is also considerable  variation in size  between individuals. Female humans are the only  mammals  which permanently develop breasts at  puberty ; all other mammals develop their mammary tissue during the latter period of pregnancy; at puberty,  estrogens , in conjunction with  growth hormone , cause permanent  breast growth .


In females, the breast serves as the  mammary gland , which produces and secretes milk to feed  infants . [ 2 ]   Subcutaneous fat  covers and envelops a network of  ducts  that converge on the  nipple , and these  tissues  give the breast its distinct size and globular shape. At the ends of the ducts are  lobules , or clusters of  alveoli , where milk is produced and stored in response to  hormonal signals . [ 3 ]  During pregnancy, the breast responds to a complex interaction of hormones, including  estrogens ,  progesterone , and  prolactin , that mediate the completion of its development, namely lobuloalveolar maturation, in preparation of  lactation  and  breastfeeding .


Along with their major function in providing nutrition for infants, several cultures ascribe social and  sexual  characteristics to female breasts, and may regard  bare breasts  in  public  as  immodest  or  indecent . Breasts have been featured in ancient and modern sculpture, art, and photography. Breasts can represent  fertility ,  femininity , or  abundance . They can figure prominently in the perception of a woman's body and  sexual attractiveness . Breasts, especially the nipples, can be an  erogenous zone .


The English word  breast  derives from the  Old English  word  brēost   ' breast, bosom '  from  Proto-Germanic   * breustam   ' breast ' , from the  Proto-Indo-European  base  * bhreus–   ' to swell, to sprout ' . [ 4 ]  The  breast  spelling conforms to the Scottish and North English dialectal pronunciations. [ 5 ]  The  Merriam-Webster Dictionary  states that " Middle English   brest , [comes] from Old English  brēost ; akin to  Old High German   brust ...,  Old Irish   brú  [belly], [and] Russian  bryukho "; the first known usage of the term was before the 12th century. [ 6 ]


Breasts  is often used to refer to female breasts in particular, though the stricter anatomical term refers to the same region on members of either sex. Male breasts are sometimes referred to in the singular to mean the collective upper chest area, [ a ]  whereas female breasts are referred to in the plural unless speaking of a specific left or right breast.


A large number of colloquial terms for female breasts are used in English, ranging from fairly polite terms to vulgar or slang. [ b ]  Some vulgar slang expressions may be considered to be derogatory or sexist to women. [ 7 ]


Humans are the only mammals whose breasts become permanently enlarged after  sexual maturity  (known in humans as  puberty ). The reason for this evolutionary change is unknown. [ 8 ]  Several hypotheses have been put forward:


A link has been proposed to processes for synthesizing the  endogenous   steroid hormone  precursor  dehydroepiandrosterone  which takes place in fat rich regions of the body like the buttocks and breasts. These contributed to human brain development and played a part in increasing brain size.  Breast enlargement may for this purpose have occurred as early as  Homo ergaster  (1.7–1.4  MYA ). [ 9 ]  Other breast formation hypotheses may have then taken over as principal drivers. [ 10 ] [ 11 ] [ 9 ]


It has been suggested by zoologists Avishag and  Amotz Zahavi  that the size of the human breasts can be explained by the  handicap theory  of  sexual dimorphism . This would see the explanation for larger breasts as them being an  honest display  of the women's health and ability to grow and carry them in her life. Prospective mates can then evaluate the genes of a potential mate for their ability to sustain her health even with the additional energy demanding burden she is carrying. [ 12 ] [ 13 ]


The zoologist  Desmond Morris  describes a sociobiological approach in his science book  The Naked Ape . He suggests, by making comparisons with the other primates, that breasts evolved to replace swelling buttocks as a sex signal of ovulation. He notes how humans have, relatively speaking, large penises as well as large breasts. Furthermore, early humans adopted bipedalism and face-to-face coitus. He therefore suggested enlarged sexual signals helped maintain the bond between a mated male and female even though they performed different duties and therefore were separated for lengths of time. [ 14 ] [ 13 ] [ 15 ]


A 2001 study proposed that the rounded shape of a woman's breast evolved to prevent the sucking infant offspring from suffocating while feeding at the teat; that is, because of the human infant's small jaw, which did not project from the face to reach the nipple, they might block the  nostrils  against the mother's breast if it were of a flatter form (compare with the  common chimpanzee ). Theoretically, as the human jaw receded into the face, the woman's body compensated with round breasts. [ 16 ]


Ashley Montague  (1965) proposed that breasts came about as an adaptation for infant feeding for a different reason, as early human ancestors adopted bipedalism and the loss of body hair.  Human upright stance meant infants must be carried at the hip or shoulder instead of on the back as in the apes. This gives the infant less opportunity to find the nipple or the purchase to cling on to the mother's body hair.  The mobility of the nipple on a large breast in most human females gives the infant more ability to find it, grasp it and feed. [ 11 ]


Other suggestions include simply that permanent breasts attracted mates, that "pendulous" breasts gave infants something to cling to, or that permanent breasts shared the function of a  camel's hump , to store fat as an energy reserve. [ 8 ]


In women, the breasts overlie the  pectoralis major muscles  and extend on average from the level of the second rib to the level of the sixth rib in the front of the  rib cage ; thus, the breasts cover much of the chest area and the chest walls. At the front of the chest, the  breast tissue  can extend from the  clavicle  (collarbone) to the middle of the  sternum  (breastbone). At the sides of the chest, the breast tissue can extend into the  axilla  (armpit), and can reach as far to the back as the  latissimus dorsi muscle , extending from the lower back to the  humerus  bone (the bone of the upper arm). As a  mammary gland , the breast is composed of differing layers of  tissue , predominantly two types:  adipose tissue ; and  glandular tissue , which affects the lactation functions of the breasts. [ 17 ] : 115   The natural  resonant frequency  of the human breast is about 2  hertz . [ 18 ]


Morphologically , the breast is tear-shaped. [ 19 ]  The superficial tissue layer ( superficial fascia ) is separated from the skin by 0.5–2.5 cm of subcutaneous fat (adipose tissue). The  suspensory Cooper's ligaments  are fibrous-tissue prolongations that radiate from the superficial fascia to the skin envelope. The female adult breast contains 14–18 irregular lactiferous lobes that converge at the nipple. The 2.0–4.5 mm milk ducts are immediately surrounded with dense connective tissue that support the glands. Milk exits the breast through the nipple, which is surrounded by a pigmented area of skin called the areola. The size of the areola can vary widely among women. The areola contains modified  sweat glands  known as  Montgomery's glands . These glands secrete oily fluid that lubricate and protect the nipple during breastfeeding. [ 20 ]  Volatile compounds in these secretions may also serve as an olfactory stimulus for the newborn's appetite. [ 21 ]


The dimensions and weight of the breast vary widely among women. A small-to-medium-sized breast weighs 500 grams (1.1 pounds) or less, and a large breast can weigh approximately 750 to 1,000 grams (1.7 to 2.2 pounds) or more. In terms of composition, the breasts are about 80 to 90%  stromal  tissue ( fat  and  connective tissue ), while  epithelial  or  glandular  tissue only accounts for about 10 to 20% of the volume of the breasts. [ 22 ] [ 23 ] [ 24 ] [ 25 ] [ 26 ]  The tissue composition ratios of the breast also vary among women. Some women's breasts have a higher proportion of glandular tissue than of adipose or  connective  tissues. The fat-to-connective-tissue ratio determines the density or firmness of the breast. During a woman's life, her breasts change size, shape, and weight due to hormonal changes during  puberty , the  menstrual cycle ,  pregnancy , breastfeeding, and  menopause . [ 27 ] [ 28 ]


The breast is an  apocrine  gland that produces the  milk  used to feed an infant. The  nipple  of the breast is surrounded by the  areola  (nipple-areola complex). The areola has many sebaceous glands, and the skin color varies from pink to dark brown. The basic units of the breast are the terminal duct lobular units (TDLUs), which produce the fatty breast milk. They give the breast its offspring-feeding functions as a mammary gland. They are distributed throughout the body of the breast. Approximately two-thirds of the lactiferous tissue is within 30 mm of the base of the nipple. The terminal lactiferous ducts drain the milk from TDLUs into 4–18 lactiferous ducts, which drain to the nipple. The milk-glands-to-fat ratio is 2:1 in a lactating woman, and 1:1 in a non-lactating woman. In addition to the milk glands, the breast is also composed of connective tissues ( collagen ,  elastin ), white fat, and the suspensory Cooper's ligaments. Sensation in the breast is provided by the  peripheral nervous system  innervation by means of the front (anterior) and side (lateral) cutaneous branches of the fourth-, fifth-, and sixth  intercostal nerves . The T-4 nerve ( Thoracic spinal nerve 4 ), which innervates the  dermatomic area , supplies sensation to the nipple-areola complex. [ 29 ]


Approximately 75% of the  lymph  from the breast travels to the axillary  lymph nodes  on the same side of the body, while 25% of the lymph travels to the parasternal nodes (beside the sternum bone). [ 17 ] : 116   A small amount of remaining lymph travels to the other breast and to the abdominal lymph nodes. The subareolar region has a lymphatic plexus known as the "subareolar plexus of Sappey". [ 30 ]  The  axillary lymph nodes  include the pectoral (chest), subscapular (under the scapula), and humeral (humerus-bone area) lymph-node groups, which drain to the central  axillary lymph nodes  and to the apical axillary lymph nodes. The lymphatic drainage of the breasts is especially relevant to  oncology  because breast cancer is common to the mammary gland, and cancer cells can  metastasize  (break away) from a  tumor  and be dispersed to other parts of the body by means of the lymphatic system.


The morphologic variations in the size, shape, volume, tissue density, pectoral locale, and spacing of the breasts determine their natural shape, appearance, and position on a woman's chest.  Breast size  and other characteristics do not predict the fat-to-milk-gland ratio or the potential for the woman to nurse an infant. The size and the shape of the breasts are influenced by normal-life hormonal changes (thelarche, menstruation, pregnancy, menopause) and medical conditions (e.g.  virginal breast hypertrophy ). [ 31 ]  The shape of the breasts is naturally determined by the support of the suspensory Cooper's ligaments, the underlying muscle and bone structures of the chest, and by the skin envelope. The suspensory ligaments sustain the breast from the clavicle (collarbone) and the clavico-pectoral fascia (collarbone and chest) by traversing and encompassing the fat and milk-gland tissues. The breast is positioned, affixed to, and supported upon the chest wall, while its shape is established and maintained by the skin envelope. [ 32 ] [ 33 ]  In most women, one breast is slightly larger than the other. [ 19 ]  More obvious and persistent asymmetry in breast size occurs in up to 25% of women. [ 34 ]


The base of each breast is attached to the chest by the deep fascia over the pectoralis major muscles. The base of the breast is semi-circular, however the shape and position of the breast above the surface is variable. [ 35 ]  The space between the breast and the pectoralis major muscle, called  retromammary space , gives mobility to the breast. The chest ( thoracic cavity ) progressively slopes outwards from the thoracic inlet (atop the  breastbone ) and above to the lowest ribs that support the breasts. The inframammary fold (IMF), where the lower portion of the breast meets the chest, is an anatomic feature created by the adherence of the breast skin and the underlying connective tissues of the chest; the IMF is the lower-most extent of the anatomic breast. Normal breast tissue has a texture that feels nodular or granular, with considerable variation from woman to woman. [ 19 ]


Breasts have been categorized into four general morphological groups:  "flat, spheric, protruded, and drooped", or "small/flat, large/inward, upward, and droopy". [ 36 ] [ 37 ] [ 38 ]


While it is a common belief that breastfeeding causes  breasts to sag , [ 39 ]  researchers have found that a woman's breasts sag due to four key factors: cigarette smoking,  number of pregnancies ,  gravity , and weight loss or gain. [ 40 ]  Women sometimes wear bras because they mistakenly believe they prevent breasts from sagging as they get older. [ 41 ]  Physicians, lingerie retailers, teenagers, and adult women used to believe that bras were medically required to support breasts. In a 1952 article in  Parents' Magazine , Frank H. Crowell erroneously reported that it was important for teen girls to begin wearing bras early. According to Crowell, this would prevent sagging breasts, stretched blood vessels, and poor circulation later on. [ 42 ]  This belief was based on the false idea that breasts cannot anatomically support themselves. [ 41 ] [ 43 ]


Sports bras  are sometimes used for cardiovascular exercise, sports bras are designed to secure the breasts closely to the body to prevent movement during high-motion activity such as running. Studies have indicated sports bras which are overly tight may restrict respiratory function. [ 44 ] [ 45 ]


The breasts are principally composed of adipose,  glandular , and  connective  tissues. [ 46 ]  Because these tissues have hormone receptors, [ 46 ] [ 47 ]  their sizes and volumes fluctuate according to the hormonal changes particular to thelarche (sprouting of breasts), menstruation (egg production), pregnancy (reproduction), lactation (feeding of offspring), and menopause (end of menstruation).


The morphological structure of the human breast is identical in males and females until  puberty . For pubescent girls in thelarche (the breast-development stage), the female  sex hormones  (principally estrogens) in conjunction with  growth hormone  promote the sprouting, growth, and development of the breasts. During this time, the mammary glands grow in size and volume and begin resting on the chest. These development stages of  secondary sex characteristics  (breasts, pubic hair, etc.) are illustrated in the five-stage  Tanner scale . [ 48 ]


During  thelarche , the developing breasts are sometimes of unequal size, and usually the left breast is slightly larger. This condition of asymmetry is transitory and statistically normal in female physical and sexual development. [ 49 ]  Medical conditions can cause overdevelopment (e.g., virginal breast hypertrophy,  macromastia ) or underdevelopment (e.g.,  tuberous breast deformity ,  micromastia ) in girls and women.


Approximately two years after the onset of puberty (a girl's first  menstrual cycle ), estrogen and growth hormone stimulate the development and growth of the glandular fat and suspensory tissues that compose the breast. This continues for approximately four years until the final shape of the breast (size, volume, density) is established at about the age of 21.  Mammoplasia  (breast enlargement) in girls begins at puberty, unlike all other primates, in which breasts enlarge only during lactation. [ 20 ]


Hormone replacement therapy , including  gender-affirming hormone therapy , stimulates the growth of glandular and adipose tissue through estrogen supplementation. [ 50 ]


In menopausal women, HRT helps restore breast volume and skin elasticity diminished by declining estrogen levels, typically using oral or transdermal estradiol. [ 51 ]


In gender-affirming hormone therapy, breast development is induced through feminizing HRT, often combining estrogen with anti-androgens to suppress testosterone. Maximum growth is usually achieved after 2–3 years. [ 52 ] [ 53 ] [ 54 ]


Factors such as age, genetics, and hormone dosage influence outcomes.


During the menstrual cycle, the breasts are enlarged by  premenstrual water retention  and temporary growth as influenced by changing hormone levels. [ 55 ]


The breasts reach full maturity only when a woman's first pregnancy occurs. [ 56 ]   Changes to the breasts are among the first signs of pregnancy. The breasts become larger, the nipple-areola complex becomes larger and darker, the  Montgomery's glands  enlarge, and veins sometimes become more visible. Breast tenderness during pregnancy is common, especially during the first trimester. By mid-pregnancy, the breast is physiologically capable of lactation and some women can express  colostrum , a form of breast milk. [ 57 ]


Pregnancy causes elevated levels of the hormone  prolactin , which has a key role in the production of milk. However, milk production is blocked by the hormones  progesterone  and  estrogen  until after delivery, when progesterone and estrogen levels plummet. [ 58 ]


At menopause, breast atrophy occurs. [ 59 ]  The breasts can decrease in size when the levels of circulating estrogen decline. The adipose tissue and milk glands also begin to wither. The breasts can also become enlarged from  adverse side effects  of  combined oral contraceptive pills . The size of the breasts can also increase and decrease in response to  weight  fluctuations. [ 60 ]


Physical changes to the breasts are often recorded in the  stretch marks  of the skin envelope; they can serve as historical indicators of the increments and the decrements of the size and volume of a woman's breasts throughout the course of her life. [ verification needed ]


Breast changes during menopause are sometimes treated with  hormone replacement therapy . [ 61 ]


Breast cancer is a cancer that develops from breast tissue. [ 62 ]  Signs of breast cancer may include a  lump  in the breast, a change in breast shape,  dimpling  of the skin,  milk rejection , fluid coming from the  nipple , a newly inverted nipple, or a red or scaly patch of skin. [ 63 ]  In those with  distant spread of the disease , there may be  bone pain , swollen  lymph nodes ,  shortness of breath , or  yellow skin . [ 64 ]


Risk factors for developing breast cancer include  obesity , a  lack of physical exercise , alcohol consumption,  hormone replacement therapy  during  menopause ,  ionizing radiation , an early age at  first menstruation , having children late in life (or not at all), older age, having a prior history of breast cancer, and a family history of breast cancer. [ 63 ] [ 65 ] [ 66 ]  About five to ten percent of cases are the result of an inherited genetic predisposition, [ 63 ]  including  BRCA  mutations  among others. [ 63 ]  Breast cancer most commonly develops in cells from the lining of  milk ducts  and the  lobules  that supply these ducts with milk. [ 63 ]  Cancers developing from the ducts are known as  ductal carcinomas , while those developing from lobules are known as  lobular carcinomas . [ 63 ]  There are more than 18 other sub-types of breast cancer. [ 65 ]  Some, such as  ductal carcinoma in situ , develop from  pre-invasive lesions . [ 65 ]  The diagnosis of breast cancer is confirmed by taking a  biopsy  of the concerning tissue. [ 63 ]  Once the diagnosis is made, further tests are carried out to determine if the cancer has spread beyond the breast and which treatments are most likely to be effective. [ 63 ]


The primary function of the breasts, as mammary glands, is the nourishing of an infant with  breast milk . Milk is produced in milk-secreting cells in the alveoli. When the breasts are stimulated by the suckling of her baby, the mother's brain secretes  oxytocin . High levels of oxytocin trigger the contraction of muscle cells surrounding the alveoli, causing milk to flow along the ducts that connect the alveoli to the nipple. [ 58 ]


Full-term newborns have an instinct and a need to suck on a nipple, and breastfed babies nurse for both nutrition and for comfort. [ 67 ]   Breast milk provides all necessary nutrients for the first six months of life, and then remains an important source of nutrition, alongside solid foods, until at least one or two years of age.


Biomechanical studies have demonstrated that, depending on the activity and the size of a woman's breast, when she walks or runs braless, her breasts may move up and down by 4 to 18 centimetres (1.6 to 7.1 in) or more, and also oscillate side to side. [ 68 ]  Researchers have also found that as women's breast size increased, they took part in less physical activity, especially vigorous exercise. Few very-large-breasted women jogged, for example. To avoid exercise-related discomfort and pain, medical experts suggest women wear a well-fitted  sports bra  during activity. [ 68 ]


The breast is susceptible to numerous benign and malignant conditions. The most frequent benign conditions are  puerperal mastitis ,  fibrocystic breast changes  and  mastalgia .


Lactation  unrelated to pregnancy is known as  galactorrhea . It can be caused by certain drugs (such as  antipsychotic  medications), extreme physical stress, or  endocrine  disorders. Lactation in newborns is caused by hormones from the mother that crossed into the baby's bloodstream during pregnancy.


Breast cancer is the most common cause of cancer death among women [ 69 ]  and it is one of the leading causes of death among women. Factors that appear to be implicated in decreasing the risk of breast cancer are regular breast examinations by health care professionals, regular  mammograms ,  self-examination of breasts , healthy diet, exercise to decrease excess body fat, [ 70 ]  and  breastfeeding . [ 71 ]


Both females and males develop breasts from the same  embryological  tissues. Anatomically, male breasts do not normally contain lobules and acini that are present in females. In rare instances, it is possible for very few lobules to be present; this makes it possible for some men to develop lobular carcinoma of the breast. [ 72 ]  Normally, males produce lower levels of estrogens and higher levels of  androgens , namely  testosterone , which suppress the effects of estrogens in developing excessive breast tissue. In boys and men, abnormal breast development is manifested as  gynecomastia , the consequence of a biochemical imbalance between the normal levels of estrogen and testosterone in the male body. [ 73 ]  Around 70% of boys temporarily develop breast tissue during adolescence. [ 34 ]  The condition usually resolves by itself within two years. [ 34 ]  When  male lactation  occurs, it is considered a symptom of a disorder of the  pituitary gland .


Plastic surgery can be performed to  augment  or  reduce  the size of breasts, or  reconstruct  the breast in cases of deformative disease, such as breast cancer. [ 74 ]  Breast augmentation and breast lift ( mastopexy ) procedures are done only for cosmetic reasons, whereas breast reduction is sometimes medically indicated. [ 19 ]  In cases where a woman's breasts are severely asymmetrical, surgery can be performed to either enlarge the smaller breast, reduce the size of the larger breast, or both. [ 19 ]


Breast augmentation surgery generally does not interfere with future ability to breastfeed. [ 75 ]  Breast reduction surgery more frequently leads to decreased sensation in the nipple-areola complex, and to low milk supply in women who choose to breastfeed. [ 75 ]  Implants can interfere with  mammography  (breast x-ray images).


In  Christian iconography , some works of art depict women with their breasts in their hands or on a platter, signifying that they died as a martyr by having their breasts severed; one example of this is  Saint Agatha of Sicily . [ 76 ]


Femen  is a  feminist  activist group which uses  topless protests  as part of their campaigns against  sex tourism [ 77 ] [ 78 ]  religious institutions, [ 79 ]   sexism , and  homophobia . [ 80 ]  Femen activists have been regularly detained by police in response to their protests. [ 81 ]


There is a long history of female breasts being used by comedians as a subject for comedy fodder (e.g., British comic  Benny Hill's  burlesque/slapstick routines). [ 82 ]


In European pre-historic societies, sculptures of female figures with pronounced or highly exaggerated breasts were common. A typical example is the so-called  Venus of Willendorf , one of many  Paleolithic   Venus figurines  with ample hips and bosom. Artifacts such as bowls, rock carvings and sacred statues with breasts have been recorded from 15,000 BC up to late antiquity all across Europe, North Africa and the Middle East.


Many female deities representing love and fertility were associated with breasts and breast milk. Figures of the Phoenician goddess  Astarte  were represented as pillars studded with breasts.  Isis , an Egyptian goddess who represented, among many other things, ideal motherhood, was often portrayed as suckling  pharaohs , thereby confirming their divine status as rulers. Even certain male deities representing regeneration and fertility were occasionally depicted with breast-like appendices, such as the river god  Hapy  who was considered to be responsible for the annual overflowing of the  Nile .


Female breasts were also prominent in  Minoan art  in the form of the famous  Snake Goddess  statuettes, and a few other pieces, though most female breasts are covered. In  Ancient Greece  there were several cults worshipping the "Kourotrophos", the suckling mother, represented by goddesses such as  Gaia ,  Hera  and  Artemis . The worship of deities symbolized by the female breast in Greece became less common during the first millennium. The popular adoration of female goddesses decreased significantly during the rise of the Greek city states, a legacy which was passed on to the later  Roman Empire . [ 83 ]


During the middle of the first millennium BC, Greek culture experienced a gradual change in the perception of female breasts. Women in art were covered in clothing from the neck down, including female goddesses like  Athena , the patron of Athens who represented heroic endeavor. There were exceptions:  Aphrodite , the goddess of love, was more frequently portrayed fully nude, though in postures that were intended to portray shyness or modesty, a portrayal that has been compared to modern  pin ups  by historian  Marilyn Yalom . [ 84 ]  Although nude men were depicted standing upright, most depictions of female nudity in Greek art occurred "usually with drapery near at hand and with a forward-bending, self-protecting posture". [ 85 ]  A popular legend at the time was of the  Amazons , a tribe of fierce female warriors who socialized with men only for procreation and even removed one breast to become better warriors (the idea being that the right breast would interfere with the operation of a bow and arrow). The legend was a popular motif in art during Greek and Roman antiquity and served as an antithetical cautionary tale.


Many women regard their breasts as important to their  sexual attractiveness , as a sign of  femininity  that is important to their  sense of self . A woman with smaller breasts may regard her breasts as less attractive. [ 86 ]


Because breasts are mostly fatty tissue, their shape can—within limits—be molded by clothing, such as  foundation garments .  Bras  are commonly worn by about 90% of Western women, [ 87 ] [ 88 ] [ 89 ]  and are often worn for support. [ 90 ]  The  social norm  in most  Western cultures  is to cover breasts in public, though the extent of coverage varies depending on the social context. Some religions ascribe a special status to the female breast, either in formal teachings or through symbolism. [ 91 ]   Islam  forbids free women from exposing their breasts in public.


Many cultures, including Western cultures in North America, associate breasts with sexuality and tend to regard bare breasts as  immodest  or  indecent . In some cultures, like the  Himba  in northern  Namibia , bare-breasted women are normal. In some African cultures, for example, the  thigh  is regarded as highly sexualized and never exposed in public, but breast exposure is not taboo. In a few  Western countries  and regions female  toplessness  at a beach is acceptable, although it may not be acceptable in the town center. [ 92 ]


Social attitudes and laws regarding  breastfeeding in public  vary widely. In many countries, breastfeeding in public is common, legally protected, and generally not regarded as an issue. However, even though the practice may be legal or socially accepted, some mothers may nevertheless be reluctant to expose a breast in public to breastfeed [ 93 ] [ 94 ]  due to actual or potential objections by other people, negative comments, or harassment. [ 95 ]  It is estimated that around 63% of mothers across the world have publicly breast-fed. [ 96 ]  Bare-breasted women are legal and culturally acceptable at public beaches in Australia and much of Europe. [ 97 ] [ 92 ]  Filmmaker  Lina Esco  made a film entitled  Free the Nipple , which is about "...laws against female toplessness or restrictions on images of female, but not male, nipples", which Esco states is an example of  sexism  in society. [ 82 ]


Breast binding , also known as chest binding, is the flattening and hiding of breasts with constrictive materials such as cloth strips or purpose-built  undergarments . Binders may also be used as alternatives to  bras  or for reasons of propriety. People who bind include women,  trans men ,  non-binary  people, and  cisgender  men with gynecomastia.