Glass Delusion (Bodies Made of Glass)

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We all know someone who is a little “fragile.” Maybe they’re really thin and lanky. They do whatever they can to protect themselves from tripping, falling, or being roughed up. It’s as if they were made of glass. But I know, you know, and they know that they’re not.

...or do they?

This wouldn’t be completely out of the ordinary. The glass delusion is one of many unique psychological disorders that have fascinated psychologists throughout history.

What Is "Glass Delusion"? 

In medieval times, believing you were made of glass was actually a common delusion among nobles. Science wasn’t that behind back then - people with the “glass delusion” were experiencing just that - a delusion. The glass delusion is one of psychology’s greatest mysteries, and certainly one of the more interesting delusions in history. 

Glass Delusion in Medieval Times

The 16th and 17th century was a time of great expansion in the Western World. European empires were starting to expand into North America and the nobles in those empires were gaining more power than ever. Big moments in art and culture happened during this time period: the Mona Lisa was painted, the Baroque period began, and experiments with glass changed the way that we view ourselves. Mirrors were invented at this time. Of course, mirrors are a part of our everyday life now, but at the time, they were considered to be more magical than practical. 

During this time, history shows that a number of nobles developed the Glass Delusion. They believed that their physical bodies were made of glass. What is so odd about the Glass Delusion is that it was most common around this particular class of people. Not everyone in Medieval Times was wrapping themselves in blankets and carefully avoiding bumping into anything. Rich, scholarly people were most likely to experience this delusion. 

Glass delusion shows up in plays and literature from this time period, including The Glass Graduate. Not all people afflicted with this delusion experienced it in the same way. Some believed that their entire bodies, from head to toe, were made of glass. Others believed that some of their internal organs were made of glass. Many men, like King Charles VI, specifically believed they had a glass butt. They even walked around with pillows strapped to their butts to avoid shattering their rear! 

King Charles VI of France

King Charles VI was one of the most famous nobles with Glass Delusion. He became the King at only 11 years old. While he was first known as Charles the Beloved, the name was quickly replaced by Charles the Mad. Starting in his early 20s, King Charles VI experienced various episodes of mental illness, including the Glass Delusion.

These episodes included thinking he was Saint George and completely forgetting that he was the King of France. He didn’t recognize his wife sometimes. For months at a time, he would refuse to bathe or change his clothes. Entire books at the time were dedicated to the different delusions that King Charles VI suffered. 

When it came to the glass delusion, King Charles VI was especially paranoid and careful. He wrapped himself up in blankets so that his butt would not break. He also had iron rods sewn into his clothing so that his body would not shatter if he bumped into another person. 

Princess Alexandra Amelie

King Charles VI is the most famous example of someone experiencing Glass Delusion, but he is not the only royal who thought they were made of glass. Princess Alexandra Amelie was the daughter of the King of Bavaria. In the 1830s, the Princess was found walking very suspiciously through her home, avoiding contact with any object. When asked what was wrong, the Princess said that as a child, she had swallowed an entire grand piano made of glass. The piano was still within her body, she said. If she touched anything, the piano would shatter. 

Why Did People Think They Were Made of Glass? 

Princess Alexandra Amelie was one of the later-known cases of Glass Delusion. Cases popped up here and there starting in the 1500s, but little to no cases were recorded after the 1840s. 

At first glance, this malady seems rather random. Why would someone believe that they were made of glass? Why were rich people the only ones truly affected by this delusion? Understanding the medical beliefs of the time period may give a little insight into how Glass Delusion became a transient mental illness, only affecting those in the noble class of the 16th through 19th centuries. 

Humorism was a study of medicine that started in Ancient Greece and Rome, and still influences our medicine today. The study was based around four “humors,” or bodily fluids that signalled some sort of mood or behavior within the body. The four humors were blood, phlegm, yellow bile, and black bile. 

Black bile is probably not what you think it is. Medical “experts” at the time believed that black bile was produced by the kidneys and the spleen. When it was produced, it caused melancholy and sadness. When your body produced an excess of melancholy, you felt heavy and sluggish. 

But there is another characteristic of black bile that is particularly important to glass delusion. When black bile was heated up, experts believed it shined like glass. This connection is why many of today’s psychologists believe that glass delusion was a manifestation of sadness or paranoia. 

Nobles and royalty were not the only people to experience sadness, so why were they affected? We have to go back to humorism for the answer. At the time, experts believed that overstimulating the mind could cause black bile to be produced in excess. If a man were to use his mind more than his body, he would be more likely to produce this bile and be afflicted by melancholy. 

Social Anxiety

Not all psychologists make this connection between intellect and glass delusion. Others believe that glass delusion is more about personal space and transparency. Authors have pointed out that the fear of breaking and shattering could be an extreme form of social anxiety. People experiencing social anxiety may have fears that they “fall on their face” or stumble in front of others. They do not want to face humiliation. In some cases, this could turn into a fear of entire body parts breaking.  

Recent Cases of Glass Delusion

Other psychologists believe that glass delusion was so common in the 16th and 17th century because glass and mirrors were such a new phenomenon. Throughout history, people have tied fear and delusion to new developments in technology or culture. 

Which theory about Glass Delusion is true? It’s truly hard to say, especially because cases of glass delusion have been reported as recently as the 20th century. These cases were isolated - entire social classes weren’t affected like they were in medieval times. But they continue to add to the mystery of the condition.

A case popped up in the 1880s. Another case popped up in the 1930s. Another case occurred in the 1960s. In this latest case, a psychologist observing the man with Glass Delusion noticed something interesting. The man had recently had an accident, and was surrounded by friends and family determined to care for and protect the man. He felt overwhelmed, and the psychologist theorized that the Glass Delusion was a way for the man to slip in and out of a state of “being there.” If he were transparent or see-through, he would not have to deal with his family’s overwhelming nature. 

What Is The Truth? 

In the centuries that followed the “outbreaks” of Glass Delusion, psychologists have learned a lot about the body and mind’s inner workings. We no longer believe that a black bile is what causes depression or anxiety. An overworked mind does not directly lead to a delusion that one is made of glass. So what is the truth behind the Glass Delusion?

We may not know for sure. There are plenty of odd, random, and transient mental illnesses that have or had affected large groups of people. Some of these odd illnesses are bound by culture or class, others have less of a pattern.

Glass delusion continues to be a fascinating topic of conversation, discussed in psychology classes and on online forums everywhere! These are some of the most interesting stories in psychology - and show us that we still have a lot to learn about the workings of the mind.

Reference this article:

Practical Psychology. (2020, October). Glass Delusion (Bodies Made of Glass). Retrieved from

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