Why is incest morally bad

Taboo incest : It stays in the family

Mark and Julie are siblings. They travel together through France during the summer holidays and spend an evening alone in a hut on the beach. In doing so, they get the idea that it could be interesting and enjoyable to sleep together. Julie is already using the pill for contraception, but Mark also uses a condom to be on the safe side. You enjoy the experience but choose to never do it again and not share it with anyone. The night remains their special secret that brings them even closer to each other. What do you think: Was it okay that the two of them had sex? "

The psychologist Jonathan Haidt of New York University asked this question to interviewees a few years ago, and most of them spontaneously answered no. Sex between siblings was obviously not okay. But why? Asked Haidt further. Because of the risk of inbreeding, some argued, just to be reminded that the couple was using contraception, doubly in fact. Because of psychological consequential damage? They weren't there either, on the contrary. Because of the legal prohibition? Incest is not banned in France. Besides, the couple had kept everything to themselves.

So there was no rational reason for the refusal of brotherly cohabitation. The interviewees had decided on their gut instincts and, in retrospect, gathered arguments for their instinctive aversion. For the psychologist Haidt a typical example of how closely a person follows his intuition in matters of morality, even if he likes to put the cloak of reason on it.

Four children with the sister

To this day, the prohibition of sexual intercourse among close family members is anchored in criminal law in Germany. Again and again politicians are calling for the incest taboo to be reconsidered. For example, the Green politician Christian Ströbele campaigned for the legalization of “brother and sister love” in 2012, while the Pirate Party demanded the abolition of the criminal law. But paragraph 173 has been implemented to this day: Patrick S., born in 1976, was sentenced to two and a half years in prison for sexual intercourse with his sister. Patrick S. had been adopted by a foster family at an early age and had only met his sister as an adult. The two have four children.

Where does the deep-seated and cross-cultural disgust for incest come from? There is no lack of attempted explanations. The Oedipus complex is particularly well known. It was conceived by Sigmund Freud, the founder of psychoanalysis. According to Freud, children desire their parents, the son their mother (as in the Greek legend Oedipus his mother Iokaste), the daughter the father. Threatened by his father's power, the son wants to kill his sire, but the social incest taboo curbs his desires.

Suppressed desire

Freud's attempt at explanation suffers from the fact that he turns the instinctive rejection of sex with close relatives into its opposite. In truth, this is a suppressed desire. That is thought around the corner, little documented and in view of the universal spread of the incest ban as an explanation does not really make sense. "The idea that boys want to sleep with their mothers seems to most men to be the silliest thing they have ever heard," said Harvard psychologist Steven Pinker, summarizing Freud's discomfort.

Another theory suggests that the incest taboo encourages children to seek partners outside of their group and thereby strengthen that group's influence. For example, if a young woman marries into another clan, she connects both families and creates a mutually beneficial alliance. The idea comes from the French anthropologist Claude Lévi-Strauss, who referred to field studies in different cultures.

Unlike Freud's Oedipus complex, Levi-Strauss’s alliance assumption does not directly contradict a biological explanation of the incest taboo. According to this, it is serious medical risks to the offspring that keep close relatives from having sex. Put simply, they are evolutionarily programmed to reject it. The health risk is traditionally also one of the bases of a legal prohibition of "incest".

Many people have one or two disease-causing genes without even realizing it. Everyone has a double set of genes in their body cells, and a defective gene can often be compensated for by its intact copy. Such “recessive” diseases are only noticeable when two copies of the faulty gene collide in a person.

Now new: We give you 4 weeks of Tagesspiegel Plus! To home page