Incest means sexual intercourse between people who are related. In many societies, it is forbidden by law and religion. Children that result from incest are more likely to have birth defects. Incest is the ultimate form of inbreeding.
The exact definition of the incest relationship varies. In some societies it is immediate relations, such as parents and their children; or brothers and sisters of the same parents. That way, intercourse between cousins is permitted.
The type of incest most often reported in the Western world is father-daughter incest. Incest between adults and children is a form of child sexual abuse. This form has been shown to cause one of the worst forms of childhood trauma, a trauma that often causes serious and long-term psychological damage, especially in the case of parental incest. Stepfathers are more likely to abuse daughters that are biologically not their own than biological fathers, since the Westermarck effect prevents strongly fathers from abusing their own daughters. In the Eastern world, especially in Japan, mother-son incest is most often reported.
The term is often misused to apply to less serious sexual relationships between related people. It is difficult to say how frequent incest is, but researchers have estimated that between 10% and 15% of people have at least one "incest experience" (this means some kind of sexual relationship falling short of actual incest). Less than 2% of these involve intercourse or attempted intercourse. Among women, research by Russell (1986) and Wyatt (1985) has given estimates as high as twenty percent (for such 'incest experience').
Incest between consenting adults is very rare, or rarely reported. Willing incest between adults is a crime in most countries, although it is seen by some as a victimless crime. The reason why it is usually prohibited is because it may lead into severely handicapped children.
Most societies have some form of incest avoidance. The incest taboo is and has been one of the most common of all cultural taboos, both in current nations and many past societies, with legal penalties imposed in some jurisdictions. Most modern societies have legal or social restrictions on closely consanguineous marriages. However, in some societies, such as that of Ancient Egypt, brother–sister, father–daughter, and mother–son relations were practiced among royalty. In addition, the Balinese and some Inuit tribes have altogether different beliefs about what constitutes illegal and immoral incest.
- Claude Lévi-Strauss. Elementary structures Of kinship. (tr.1971)
- Herman, Judith (1981). Father-daughter incest. Cambridge, Massachusetts: Harvard University Press. pp. 282. ISBN 0-674-29506-4.
- Wolf, Arthur P.; William H. Durham (2004). Inbreeding, incest, and the incest taboo: the state of knowledge at the turn of the century. Stanford University Press. pp. p170–172. ISBN 0804751412.
- Courtois, Christine A. (1988). Healing the incest wound: adult survivors in therapy. Norton. pp. p208. ISBN 0393313565.
- Nemeroff, Charles B.; Craighead, W. Edward (2001). The Corsini encyclopedia of psychology and behavioral science. New York: Wiley. ISBN 0-471-24096-6.
- Hipp, Dietmar (2008-03-11). ""German High Court takes a look at incest"". Der Spiegel. http://www.spiegel.de/international/germany/0,1518,540831,00.html. Retrieved 2008-04-12.
- Brown, Donald E., Human Universals. New York: McGraw-Hill, 1991, p. 118-29
- Turner, Jeffrey S. (1996). Encyclopedia of relationships across the lifespan. Greenwood Publishing Group. pp. p92. ISBN 031329576X.
- Incest: the nature and origin of the taboo, by Emile Durkheim (tr.1963)
- Kinship, incest, and the dictates of law, by Henry A. Kelly, 14 Am. J. Juris. 69
- Maurice Godelier, Métamorphoses de la parenté, 2004
- "New Left Review - Jack Goody: The Labyrinth of Kinship". http://newleftreview.org/?view=2592. Retrieved 2007-07-24.
- Bateson, Gregory (2000). Steps to an ecology of mind: collected essays in anthropology, psychiatry, evolution, and epistemology. University Of Chicago Press. ISBN 978-0226039053.
- Briggs, Jean (2006). Never in anger: portrait of an Eskimo family. Harvard University Press. ISBN 978-0674608283.