The 21 Grams Experiment

3rd May 2018. Reading Time: 6 minutes General, Famous Paranormal Cases. 4409 page views. 1 comments.

In 1907, Dr Duncan MacDougall published an article in the New York Times which attracted a lot of attention.  It was based on his experiment to test the theory that a person’s soul has a physical weight.  It was called the 21 grams experiment. Konstantin Korotkov, took this theory further where he claims to have photographic proof through Kirlian photography of a soul leaving the body.

In 1907, Dr Duncan MacDougall published an article in the New York Times which attracted a lot of attention. It was based on his experiment to test the theory that a person’s soul has a physical weight. It was called the 21 grams experiment. This theory is still discussed today. A Russian Scientist Konstantin Korotkov took this theory further a century later where he used Kirlian photography to see if he could capture on film the moment a soul leaves the body.

21 Grams Experiment

In 1901, a Doctor by the name of Duncan MacDougall had a thought. What if the human soul actually weighed something. Could this be recorded when a person dies? It was here that the 21 grams experiment first took off. Amongst the company of 4 other assisting Doctors, 6 patients who were near the end of life were placed on specially made weight plated beds using special beams that could measure a person’s weight. The Dr’s planned to weigh each body before and after death to see if there was a different in the measurements.

The first patient passed away. MacDougall noted a weight loss quoting in a future article published in the New York Times in 1907: Suddenly, coincident with death, the beam end dropped with an audible stroke hitting against the lower limiting bar and remaining there with no rebound. The loss was ascertained to be three-fourths of an ounce.

The second patient saw similar results. MacDougall quoted in his article :
'The instant life ceased the opposite scale pan fell with a suddenness that was astonishing – as if something had been suddenly lifted from the body. Immediately all the usual deductions were made for physical loss of weight, and it was discovered that there was still a full ounce of weight unaccounted for’

The third patient in the experiment initially maintained the same weight when he died. After 1 minute, he suddenly lost 1 ounce. MacDougall quoted this discrepancy as: 'I believe that in this case, that of a phlegmatic man slow of thought and action, that the soul remained suspended in the body after death, during the minute that elapsed before its freedom. There is no other way of accounting for it, and it is what might be expected to happen in a man of the subject’s temperament.'


Sadly 2 patients results could not be measured due to either equipment failure or the patient dying before all of the measuring equipment could be set up.

MacDougall and his team of 4 other Doctors separately recorded the results of the four patients they were able to record. The compared their results afterwards. They took into account the fact that the lungs were no longer breathing air and the loss of bodily fluids which would occur when a person dies. Not all patients lost the same amount of weight. On an average though, it was calculated that they lost 21 grams. The conclusion was that the human soul weighs 21 grams.

The next step in Macdougall’s research was a plan to capture photographic evidence of a soul leaving a person’s body as they died. Unfortunately, he never got to continue his studies as he passed away in 1920. The 21 grams experiment has not been repeated on humans despite the large amount of attention it has gathered even 100 years later. Experiments have been carried on animals and in each experiment it was noted there was no loss of weight, adding to this theory that the human soul weighs 21 grams.

The experiment itself is heavily criticked by the medical and scientific community. The results were somewhat flawed and the sampling rate (only 4 patients recorded results) was far to small to make any real conclusions. The concept itself opens up a pandora's box of ethical and religious implications making it a very controversial experiment and topic.

Kirlian Photography

Following this same concept, Russian Scientist Konstantin Korotkov who is a leader in the field of Kirlian Photography (known as auro photography) claimed to have used this technology to capture photographic proof that the soul leaves the body. He photographed a person who was reaching the end of life. Apparently blue in the photos shows the life force of a person. As they were dying, this blue dissapeared and he used this as 'evidence' that the soul had left the body. According to the paper that Konstantin published (that is available to view here), the investigations were carried out in the same room using the same equipment and the same ambient room temperature of 18 degrees maintained by thermastat controllers. The experiments were conducted over a span of 2 years. Patients were both men and women aged between 19 and 70 years old.

Kirlian photography almost looks like a thermal image of a person and temperature obviously can affect this. Critics of this experiment have started that the visual changes are due to the body temperature change and body going through a decompression which causes a variation in the results and does not provide any proof of a soul leaving the body. In fact it has been widely debated that the method of Kirlian photography is not reliable in this sort of study. The paper published for this story quotes: "Apart from the touched upon subject, a number of extremely interesting issues arise: investigation of the very moment of transition, from the condition of life to the condition of death in reanimation departments, disclosing peculiarities and features of such a transition. We have received provisional data demonstrating that in some cases in a few days before death the raise of patient’s activity and increase of gas-discharge intensity are observed. Such data may provide for a new information on the process of Transition to other Life. Another problem − the influence of diseases, traumas, mental health and dying condition on the process of posthumous transformation."

While some people believe this is the actual photo taken during the studies, this is incorrect. This photo is used on a lot of research articles but is actually a photo of what happens to the human body when you enter a Sauna (It has been debunked on various internet sites drawing further skepticim to this study). If you see this picture advertised as proof of the soul leaving the body, it is not. It is a fake.

It is worth noting even though this measure is heavily criticised, Doctors all over the world use Korotkov's Kirlian technology to help monitor patients and their stress levels in hospitals. Does this mean it can capture our soul leaving our body? Again we will never really know. If you would like to read more on how Kirlian photography works, see my article What is Kirlian Photograhy?

It is an interesting yet very controversial concept. It also has a lot of religious implications as well. Regardless of the experiments, It is widely believed that we are more than our physical bodies. The soul seems to be the one thing that a lot of people even from different religions seem to believe in in some way. What is a soul? Can it really be measured and weighed? Maybe we aren’t supposed to validate it’s existence. The experiment itself creates a lot of debate, especially in medical and scientific fields. The 21 Grams research is quite ground-breaking for it’s time, 1907 was a very different time and in today’s society it would not be considered ethical which is why it has not been recreated. Does this experiment prove that our soul leaves our body when we die? Probably not, but it is a nice thought that there is something more for us waiting. That is the part I hold on to.

Don't forget to LIKE the Facebook page for updates on new content

If you enjoy LLIFS, consider buying me a book (otherwise known as buy me a coffee but I don't drink coffee and I LOVE books). Your donation helps to fund the LLIFS website so everyone can continue to access great paranormal content and resources for FREE!

Follow LLIFS on Facebook

Don't forget to follow the Facebook page for regular updates 

Mailing List

Join the mailing list to receive weekly updates of NEW articles.  Never miss an article again!

Haunted Magazine

Buy the latest and past issues Haunted Magazine

Books by LLIFS

Check out the books written by LLIFS


  • Joseph Kapusta 5 years ago

    This idea is interesting (and ideas are always desired & welcomed to advance the field of research) but avails itself of one fundamental flaw from my own observations and investigation techniques testing for temperature changes indicative of spirit presence. By declaring that the soul has weight, however minute, it also follows that it has mass. If it has mass it can absorb heat but more importantly, being above absolute zero (ghosts/spirits/soul shouldn't exist at absolute zero according to the Third Law of Thermodynamics) emit radiation detectable within the infrared spectrum. In other words, it should be observable in our physical existence. Contrary to the popular "a cold spot is indicative of spirits drawing energy from their nearby environment, people, batteries, etc." this presence of the soul should then be detectable even momentarily, as mechanical energy, even as it entropy continually increases. This detection could not be accomplished with an IR thermometer. They require the target of measurement to have a surface. You would also have to simultaneously measure the air and/or the effect of temperature changes of nearby walls and floor. This puts us right back where we started, aligned with the first law of thermodynamics, questioning where did this energy go, that which cannot be destroyed. The great question remains. What is consciousness?