The Science of Monsters

Can the symptoms of possession be medically explained? Several disorders have been associated with possession including Tourette’s syndrome and schizophrenia because of symptomatic erratic and psychotic behavior. Possession can also be linked to dissociative identity disorder with about 29 percent of those with the disorder identifying themselves as demons. Many mental and mood disorders could cause the psychological symptoms of possession.

Besides the mental health aspect, there are some physical presentations of being possessed. Some victims of possession report words appearing on their skin. Doctors believe this can be explained by dermatographic urticaria, a disorder that translates to “writing on the skin.” Those with this disease can create welt-like lines on their skin just by applying some pressure. This could appear quite worrying to anyone with no knowledge of the condition. Another physical symptom in possession cases is the vomiting of objects. This could be explained by an eating disorder known as pica. People who suffer from this disorder are known to eat non-nutritive things such as dirt, glass, and other items.

What does an exorcism entail? According to the Catholic Church:

The priest delegated by the Ordinary to perform this office should first go to confession or at least elicit an act of contrition, and, if convenient, offer the holy Sacrifice of the Mass, and implore God’s help in other fervent prayers. He vests in surplice and purple stole. Having before him the person possessed (who should be bound if there is any danger), he traces the sign of the cross over him, over himself, and the bystanders, and then sprinkles all of them with holy water. After this he kneels and says the Litany of the Saints, exclusive of the prayers which follow it. All present are to make the responses.⁴

Malachi Martin, a former Jesuit priest and self-proclaimed exorcist, offers additional information in the book Hostage to the Devil.⁵ He considers there to be four stages of an exorcism:

1. Pretense: The demon is hiding its true identity.

2. Breakpoint: The demon reveals itself.

3. Clash: The exorcist and the demon fight for the soul of the possessed.

4. Expulsion: If the exorcist wins the battle, the demon leaves the body of the possessed.

Does the Catholic Church endorse or train exorcists? The Vatican first issued official guidelines on exorcism in 1614 and revised them in 1999. According to the U.S. Conference of Catholic Bishops, signs of demonic possession include superhuman strength, aversion to holy water, and the ability to speak in unknown languages. Other potential signs of demonic possession include spitting, cursing, and “excessive masturbation.” There is an official International Association of Exorcists, which represents more than two hundred Catholic, Anglican, and Orthodox priests. The Vatican itself held an exorcist training workshop in 2018 after the increase of reported demonic possessions. The Church of England released guidelines that say “doctors, psychologists, and psychiatrists should be consulted where appropriate, and that deliverance should be followed up with continuing pastoral care and should be done with a minimum of publicity.”⁶

The crucifix is a strong religious symbol in the Catholic faith.

Are there stories of demonic possession in other cultures or religions? Anthropologists have concluded that in some cultures, those with little or no social influence can vent their true feelings toward the more powerful members of their society while “possessed” without having to face any repercussions. They are not held responsible for their actions; the possessing spirit is. Also, historically in Europe, it was women who were much more likely to be “possessed” than men. Exorcism rituals are found in many religions around the world, including Hinduism, Buddhism, Taoism, Shintoism, Judaism, and Islam. There are several references to possession by evil spirits and exorcism in the Qur’an and the Bible. Experts agree that religious beliefs can play a role in the diagnosis and treatment of “possessed” people.

One famous scene in The Exorcist shows Linda Blair’s character Regan projectile vomiting onto the priest. For filming, real pea soup was used and mixed with oatmeal to look more authentic. (Gross!) What is the science behind projectile vomiting? The forced ejection of stomach contents can by caused by a variety of things. In infants, it’s most often due to a condition called pyloric stenosis. This condition affects a tube in the child’s body that connects the small bowel and the stomach. This condition can be repaired through surgery. In adults, projectile vomiting is quite rare. When it happens though its common causes are food poisoning, toxins such as alcohol, or illness. Although this type of vomiting causes no long-term effects, any type of throwing up can be traumatic.