Incest Laws in the United States

A gavel.

Incest is defined as “sexual intercourse between persons so closely related that they are forbidden to marry; also: the statutory crime of such a relationship1.” In more simple terms, incest is sexual intercourse between people who are very closely related. Incest can occur between people in a consanguineous relationship or between people who are related by affinity. Consanguineous relatives are people who are related by blood. People related by affinity are step-relatives, those related through adoptive measures or marital status, members of the same household, or in other cultures, members of the same clans and lineages.

Incest is widely held to be a universal taboo, with almost all cultures frowning upon incestuous relationships. In the United States, as with a lot of sexual assaults, incest is extremely underreported2. Nationally-reported statistics regarding incest may be inaccurate because incest is often concealed by victims and not discussed at large in society. Survivors may be hesitant to come forward because of guilt, shame, fear, social and familial pressure, and/or coercion from the perpetrator. Research shows that 46% of children who had been raped had been assaulted by a family member or close relative2. Younger victims of incest are most often assaulted by people in a trusted position, and therefore are led to believe the lies, explanations, and threats of this person. Perpetrators may lead the child to believe it is a learning experience that all children must go through; some victims may not even know that what is being done to them is wrong.

In the United States, incest is a sex crime that is usually punishable by law. All incestuous relationships involving minors are illegal; these survivors of incest are protected by child abuse laws2. In all states, incestuous marriages are illegal3. In most states, committing incest is a class C felony3.  However, certain states do not have laws explicitly prohibiting incestuous relationships, as long as the people in the relationship do not attempt to marry. The exact laws regarding incestuous relationships vary drastically by state. The following are just a few examples of the more lenient incest laws:

Arkansas: (a) A person commits incest if the person, being sixteen (16) years of age or older, purports to marry, has sexual intercourse with, or engages in deviant sexual activity with another person sixteen (16) years of age or older whom the actor knows to be:

(1) An ancestor or a descendant;
(2) A stepchild or adopted child;
(3) A brother or sister of the whole or half blood;

(4) An uncle, aunt, nephew, or niece; or
(5) A step grandchild or adopted grandchild

According to this Arkansas legislature, incestuous marriages and sexual relationships are illegal with a relative over age 16. Therefore, two related individuals under the age of sixteen who choose to have sexual relations are not technically committing incest. However, they may be committing other crimes depending on state-by-state age of consent laws.

New Jersey: a. A man shall not marry or enter into a civil union with any of his ancestors or descendants, or his sister or brother, or the daughter or son of his brother or sister, or the sister or brother of his father or mother, whether such collateral kindred be of the whole or half blood.

b. A woman shall not marry or enter into a civil union with any of her ancestors or descendants, or her sister or brother, or the daughter or son of her brother or sister, or the sister or brother of her father or mother, whether such collateral kindred be of the whole or half blood.

c. A marriage or civil union in violation of any of the foregoing provisions shall be absolutely void3.

In New Jersey, only incestuous marriages are illegal. Incestuous relationships are not illegal. This means that while a brother and sister may not marry and receive the legal benefits of a married status, they may privately engage in an incestuous relationship and will not be prosecuted for this. However, just because the relationship itself is not technically illegal, the potential offspring of such a relationship are very likely to be born with birth defects.

Ohio: (A) No person shall engage in sexual conduct with another, not the spouse of the offender, when any of the following apply:

The offender is the other person’s natural or adoptive parent, or a stepparent, or guardian, custodian, or person in loco parentis of the other person3.

Ohio only punishes offenders of incest if they are the parents of the victim(s).

Rhode Island: (A) No man shall marry his mother, grandmother, daughter, son’s daughter, daughter’s daughter, stepmother, grandfather’s wife, son’s wife, son’s son’s wife, daughter’s son’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s son’s daughter, wife’s daughter’s daughter, sister, brother’s daughter, sister’s daughter, father’s sister, or mother’s sister.

(B) No woman shall marry her father, grandfather, son, son’s son, daughter’s son, stepfather, grandmother’s husband, daughter’s husband, son’s daughter’s husband, daughter’s daughter’s husband, husband’s father, husband’s grandfather, husband’s son, husband’s son’s son, husband’s daughter’s son, brother, brother’s son, sister’s son, father’s brother, or mother’s brother3.

Rhode Island only targets incestuous marriages. Rhode Island, New Jersey, and Ohio have the most lenient incest laws, mostly prohibiting only incestuous marriages. It is important to recognize that these states do not condone incestuous relationships with relatives under 18; the already-in-place laws against sexual relationships with minors protects against those relationships.

While the states listed above may seem to “approve” of some types of incestuous relationships by not having specific laws preventing certain types of sexual relationships, this is not the case. Even though these states may seem relaxed about incestuous relationships, incest can still be extremely harmful and is discouraged across the United States.

Biological Costs of Incest

A person sitting on top of another person. They are holding hands.

Most people have a very strong “yuck” factor towards sexual thoughts of their first-degree relatives. While many people might believe this is a learned social convention, it is more likely a biological mechanism our bodies use to avoid the dangers that come with bearing children of incestuous relationships4. In fact, humans are not the only species that has evolved to avoid incestuous relationships or inbreeding. Plants and animals have adapted special mechanisms to avoid mating with first-degree relatives4. The reason this incest avoidance occurs is quite straightforward: offspring of first degree relatives have a very high chance of being born with a birth defect.

Research shows that children of brother-sister or father-daughter relationships have nearly a fifty percent chance of facing severe birth defects, mental deficiency, or early death. The offspring are likely to be born with autosomal recessive disorders, congenital physical defects, or severe mental deficits. Moreover, these birth defects will remain with the child for the rest of his or her life4.

Psychological Costs of Parent-Child Incest

Survivors of childhood sexual abuse from a parent or relative may encounter many short- and long-term effects of the abuse. Survivors may feel guilt and shame about the abuse. They may feel disgusted, or blame themselves for not being able to stop the abuse. It is imperative to understand that it is not the survivor’s fault that the abuse happened. The only person who should be held accountable is the relative who inflicted the abuse.

An adult survivor of childhood incest may experience difficulty in intimacy and relationships2. It is likely that the survivor’s first sexual experience was an instance of sexual abuse. After entering adulthood, the survivor might have problems trusting partners, desiring intimacy, or feeling comfortable in sexual relationships2. Low self-esteem may occur as a result of the abuse, which can affect the relationships, career, and health of the survivor. This low self-esteem could be a result of having personal safety violated by a person in a position of trust or power. Abusers may also send negative messages to their victims in order to maintain their secrecy, which could contribute to psychological issues.

If you are a survivor of sexual abuse, including incest, it is important to remember that the abuse was not your fault. The only person that is responsible for sexual assault is the perpetrator of the crime. As a survivor of sexual assault, you may feel uncomfortable in intimate and romantic relationships. Remember that even though you experienced a sexual violation, you are still allowed to be a sexual being. If you feel uncomfortable in sexual relationships but desire intimacy, consider seeing a counselor or psychologist. If you are a survivor of incest, remember that you could not do anything to stop the assault and it is no way your fault. It may be possible that your self-esteem has been affected. You may feel ashamed or guilty; but there is nothing to be ashamed of! Remember, you are completely normal and the abuse was not your fault. If the assault continues to affect your daily life and self-esteem, help is out there! Help for survivors of incest is available. Support groups, hotlines, and counseling may offer help from psychological trauma of abuse. If you or someone you know needs help with sexual abuse/assault, please call the National Sexual Assault Hotline: 800-656-HOPE (4673)


  1. “Incest.” Merriam-Webster. Merriam-Webster, n.d. Web. 10 Mar. 2016.
  2. “Factsheets: Incest.” Sexual Violence Free New York. New York City Alliance Against Sexual Assault, n.d. Web. 10 Mar. 2016.
  3. “Statutory Compilation Regarding Incest Statutes.” National Center For Prosecution Of Child Abuse National District Attorneys Associat (2013): n. pag. National District Attorny Association, 1 Mar. 2013. Web. 10 Mar. 2016.
  4. “The Problem With Incest.” PsychToday. Psychology Today, 11 Oct. 2012. Web. 10 Mar. 2016.

Last Updated: March 10, 2016