In the Old Testament of the Bible, the punishment for adultery was stoning. In most countries today, the legal punishment is milder. However, there are often social penalties even when adultery is not prosecuted legally.
Adultery is sexual intercourse between a married person and someone who is not his spouse. In modern times, if a married person has sex with an unmarried person, it is often the case that only the married party is considered to have committed adultery, although this may vary by legal jurisdiction. In some legal systems, adultery is defined by the wife's behaviour, not the husband's. For instance, the state of Minnesota specifically defines adultery as the wife having sex outside her marriage.
Many Western countries have decriminalised adultery, and it is not legally punishable in nations such as Austria, Finland and Sweden. In the United States, punishment for adultery can vary widely from state to state, from life imprisonment (Michigan) to a small monetary fine (Maryland). However, though adultery laws may still be on the books in the U.S., they are rarely enforced. In contrast, some countries such as Iran or Pakistan call for severe punishment for adultery.
Though civilians are rarely prosecuted for adultery in the U.S., adultery by military personnel can be severely punished under article 134. This is because adultery, especially with another member of the military, is seen to have a negative impact on morale and discipline.
Alfred Kinsey's famous reports on human sexuality in the late 1940s and early 1950s found that about half of all American men and about a quarter of all women had extramarital sex at least once in their lifetimes. Subsequent studies have found that while many men and women may have strayed once or twice during a marriage, the incidence of adultery in any given year is quite low, however. In other countries, the prevalence of adultery may be much lower or occasionally much higher. For instance, a study in Korea found adultery rates in men to be about 68 per cent.
Even when adultery is not punished legally, it can have social consequences. Adultery can be cited as the grounds for divorce under fault-based divorce laws, for instance. Also, those who commit adultery often suffer from social stigma, though that stigma has decreased in the United States in recent decades.
The concept of adultery has had a big impact on literature throughout the ages, from Shakespeare to modern times. For instance, the suspicion of adultery is central to the plot of "Othello" and is important in "The Winter's Tale." Adultery is a major theme in famous novels including "Anna Karenina," "Madame Bovary" and "Damage," as well as the novella "The Scarlet Letter."