Alienation of affection is a controversial American law that allows legal action against a third party who can be shown to have contributed to the end of a marriage. Although no longer applicable in many areas, eight US states continue to allow alienation of affection suits to be filed. Many modern legal scholars consider these laws to be archaic and no longer relevant to modern law, but courts continue to see many suits filed under this law each year.
Although requirements vary somewhat from state to state, an alienation of affection lawsuit generally seeks to prove a causal relationship between a marriage becoming dysfunctional or unsustainable and a third party's influence. Often, the charges are brought against a third party believed to be romantically or sexually involved with a married person. In some instances, charges can be leveled against a third party who has counseled or suggested divorce, such as a therapist, relative, or even member of the clergy. Most versions of the law stipulate that the accused party does not necessarily have to intend to cause the end of a marriage, but nonetheless can be shown to have contributed to divorce or separation.
During the 19th century, most states in America had some form of the alienation of affection law on the books. As modern attitudes toward marriage and divorce changed throughout the 20th century, these laws were slowly overturned in many states, either by legislation or by a court's ruling. At the turn of the 21st century, only eight states retain some law regarding alienation of affection: Hawaii, Missouri, Mississippi, New Hampshire, New Mexico, North Carolina, Utah, and South Dakota.
It is important to distinguish alienation of affection laws from those permitting legal action in the case of adultery. Adultery cases, which are common in some US states as well as internationally, are brought against a married person who is believed to have had sexual relations outside the marriage, thereby breaking the contract of the marriage. In areas of the United States where adultery cases are admissible, the rulings often have an affect on child custody and spousal support decisions. Alienation of affection cases are instead brought against a third party rather than one of the married pair.
Internationally, alienation of affection laws are difficult to pinpoint. Although many countries have stiff laws against adultery, they vary greatly in the method of apportioning guilt or blame. In the United States, where alienation laws were once a near universal part of state law, the concept has fallen mostly out of legal fashion.