Zombies, ghosts, and Frankenstein: Medical origins of Halloween monsters

By John Murphy, MDLinx
Published October 24, 2023

Key Takeaways

  • Almost all modern-day movie monsters originate from real-life stories.

  • Two medical discoveries were the inspiration behind Frankenstein's monster: resuscitation from drowning and electrophysiology.

  • A significant portion of Americans believe in ghosts, but seeing them could be a tip-off to neurodegenerative conditions, such as Parkinson’s disease or Lewy body dementia.

Zombies, ghosts, and reanimated corpse-monsters don’t really exist… do they? Of course not! But then again… Some of the lore behind these Halloween creatures has its basis in scientific and medical fact. For example, certain people actually do see ghosts (but whether those ghosts exist in reality is another matter).

Here’s a look at the scientific origins and medical conditions that are really behind the folklore and legends of the creepy things that go “bump” in the night.


Characteristic features: flat affect, progressive decomposition, torpor, staggering gait, loss of cognitive function, severe halitosis, zero heart rate, insatiable hunger for brains.

The lurching, undead, reanimated corpses that we know and fear today, from movies such as Night of the Living Dead and television shows like The Walking Dead, are different from their zombie ancestors in folklore.

The word “zombie” was first recorded in 1819 and stems from the Haitian French zombi or Haitian Creole zonbi, either of which may have its origins in nzumbi from Africa. Like our modern brain-eating zombies, Haitian zombies are reanimated corpses, but are usually created through magic or witchcraft and not viruses or plagues. These zombies are mute automatons typically under the control of a sorcerer or witch (bokor) and act as personal slaves with no will of their own.

Zombies are still reported in Haiti. A 1997 article in The Lancet described three case reports of modern-day “zombification.”[] One report involved a woman in her 30s who reportedly died of febrile illness and was buried. Three years later, she was seen wandering in the village, and was identified by family and friends. Her tomb was opened and found to be full of stones. She was admitted to the psychiatric hospital in Port-au-Prince.

Upon examination, she kept her head constantly lowered and she walked extremely slowly and stiffly, barely moving her arms. She did not respond to questioning and when she did talk, her speech was nearly incomprehensible. The presumptive diagnosis was catatonic schizophrenia, “which is locally a not uncommon psychiatric illness,” the authors wrote.

"It is unlikely that there is a single explanation for all zombis. Mistaken identification of a wandering, mentally ill stranger by bereaved relatives is the most likely explanation."

Authors, The Lancet

“People with a chronic schizophrenic illness, brain damage, or learning disability are not uncommonly met with wandering in Haiti, and they would be particularly likely to be identified as lacking volition and memory, which are characteristics of a zombi,” they concluded.

By the way, eating brains doesn’t come from zombie folklore. It’s a movie trope that didn’t even appear in modern pop culture until the 1985 zombie comedy film The Return of the Living Dead.


Characteristic features: transparent and incorporeal habitus, pathologic moaning, frequent floating, ectoplasmic disgorgement, melancholy.

Ghosts appear in the folklore of every culture. Even in current times, 32% of Americans believe in ghosts — a number that has been rising incrementally in recent years, according to a Gallup Poll.[]

Any number of hypotheses seek to explain ghosts. In the world of medicine, however, seemingly normal people who report seeing ghosts or monsters may actually be having extremely vivid visual hallucinations. Such hallucinations may seem relatively harmless in themselves, but they could be a tip-off to a serious neurodegenerative condition, such as Parkinson’s disease or Lewy body dementia.

In one case in Japan, a 60-year-old man reported several ghost sightings.[] In one, six specters broke into his living room. The ghosts didn’t respond when the man questioned them, and they disappeared when he tried to tap one ghost on the shoulder. In the second sighting, the man got up from bed in the middle of the night and found his wife lying in the hallway, bleeding from stab wounds. When he reached out to help her, she too disappeared at his touch.

Neurologists diagnosed posterior cortical atrophy caused by Lewy body dementia or Alzheimer’s disease. Atrophy of his occipital and temporal lobes and decreased cerebral perfusion in the parietal and frontal lobes likely induced the man’s vivid visual hallucinations.

“We propose that some ghost sightings are actually visual hallucinations in normal people, which occur very rarely but more frequently than we in the medical establishment think,” the neurologists wrote.

Other possible medical causes for ghosts include “paranormal” experiences caused by traumatic stress as well as visual hallucinations that occur with sleep paralysis.

Frankenstein’s monster

Characteristic features: greenish pallor, lumbering gait, numerous stitches and surgical scars, poorly developed social skills (due to abnormal brain?), pyrophobia, bolts in neck.

The historical origin of the story of Frankenstein is fairly well known. One dark and stormy night, Mary Shelley and husband-to-be/poet Percy Bysshe Shelley were cooped up in a mansion with Lord Byron and some other literary folk. Byron challenged them all to come up with a terrifying ghost story. Mary Shelley, just 18 years old at the time, told the tale that would later become her 1818 novel Frankenstein — and she won the challenge.

The medical origins of Frankenstein’s monster are not quite as well known, but they stem from at least two revolutionary discoveries in science and medicine in the late 18th century.

The first discovery was resuscitation from drowning. Not until the late 18th century did physicians realize that some people who appeared dead from drowning could be revived if quickly rescued from the water and immediately given resuscitation measures.

As it happened, Mary Shelley’s mother, philosopher Mary Wollstonecraft, attempted suicide by leaping from a bridge in 1795, about 2 years before her daughter was born. But some alert boatmen pulled Wollstonecraft’s unconscious body out of the river and resuscitated her — much to her disappointment. Two years later, she died from a postpartum infection just 10 days after her daughter was born. Not surprisingly, the ideas of bringing life from the dead as well as that of a “motherless child” are both significant themes in the novel.

The second revolutionary discovery was that of electrophysiology. In the late 1700s, scientists demonstrated that an electrical current — from a lightning storm, an electrical machine, or the newly invented electric battery — could be applied to the nerves of a dead animal to stimulate its muscles into motion. In one demonstration, the dismembered head of an ox twitched and open its eyes.

In 1803, a more sensational experiment involved the application of electrical current to the corpse of an executed convict, which caused the body to convulse. When the current was applied to the convict’s face, his jaws clenched and his eyes opened. Attendees to the event had never seen anything like it.

Mary Shelley was well aware of these developments, which contributed greatly to the creation of her novel. The story still provokes philosophical questions about taking responsibility for our creations and whether science should experiment with forces that could lead to harmful, unintended consequences. Even today, genetically modified “Frankenfoods” and genetically engineered “designer babies” are a focus of much debate.

What this means for you

Many modern-day monsters can be medically explained. A zombie's slow, stiff walk and incomprehensible speech mirrors symptoms in some patients with catatonic schizophrenia. Seeing ghosts can be explained as hallucinations brought on by traumatic stress, sleep paralysis, or neurodegenerative disease. And Frankenstein's monster was brought to life by electrophysiology — using electric current to stimulate involuntary actions, such as opening of the eyes and muscle spasms.

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