Saturday, April 16, 2011

Does the Human Soul Weigh 21 Grams?

Despite the notion that “faith” is the belief in people, concepts or things in the absence of evidence or in the face of contradictory evidence,  people of faith quietly hope that their beliefs will be vindicated through legitimate, scientific means. This is why expeditions to find Noah’s Ark occur on a regular basis and why stories of “documented” miracles regularly spread through the internet.

As such, people of faith are inclined to enthusiastically spread memes that purport to show evidence of supernatural phenomena from the world of medicine.  One such instance centers on the idea that the weight of the human soul can be measured via the scientific method. Has this occurred? Has this claim been investigated using the full weight of scientific reasoning? Has science proved that the human soul has weight?

The modern basis for this belief originated with an experiment by Dr. Duncan MacDougal of Haverhill, Massachusetts in 1907. After he and a team of doctors performed weight measurements on six dying subjects, he determined that the weight of an average soul was 21 grams. Using a specific methodology and publishing the results, he found that the average human body weighed 21 grams less after death than before. And there you have it – proof that the human soul can be measured with the tools of science and shown to exist!


Not so fast. As it turned out, Dr. MacDougal’s methods were shoddy and soon proven to be inaccurate. First, the sample size was much too small – only six subjects. Second, the doctor and his assistants were unable to detect the exact moments of death – a key factor in these experiments. Third, his methods for measuring weight changes were crude and unreliable. Fourth, his methods failed to account for other, more pedestrian, explanations for unexplained weight loss. And finally, his findings were never duplicated in follow-up experiments performed by other scientists – a key requirement of the scientific method.

Now of course, people of faith will raise many objections upon reading this. “Well, maybe the weight of the soul is beyond science.” This is false, of course, because weight-changes in material objects are exactly what science is qualified to measure. “Well, the standards of science are too strict for supernatural claims.” Scientific standards of inquiry, which have resulted in everything from the eradication of polio to the rise of smartphones, should not be relaxed when confronted with supernatural claims. “Science cannot prove that the soul doesn’t exist.” True, science can only show that specific claims regarding the soul are false. And all supernatural claims, when put to the test, fail to convince. Not a single supernatural claim has withstood scrutiny. Ever.
Does the soul weigh 21 grams? The evidence does not support this conclusion.   MORE INFO: Does The Human Soul Have Weight?


  1. Of course the soul has no weight. This seems like a no brainer to me. Does anybody actually believe this stuff?

  2. Don't say "ever", as in 'Never'! I have seen video that was analyzed by a physicist and video expert from Cal-tech and they both were amazed and officially said the video was not doctored.... and the physicist clearly stated that because of the laws of gravity, the objects that were caught on video were following rules of physics and not being moved by anybody. I will try to find the video. Perhaps it is on youtube.
    Although I actually saw that experiment to which you are referring, (believe it or not I actually saw that video in a movie about the supernatural in a theater when I was like 10 years old or so. I remember my mom and I were going to the movies, and there was nothing else playing that was ok for a 10 yr old so we went to that one. It was interesting, and I have never forgotten that part of the movie. It intrigued something in me. I do know that I have also read that nobody has really been able to set up a very good, definitive experiment to actually test this theory that the body weighs less at the moment of death. For mostly the reasons you have mentioned. Plus, most people probably wouldn't want to participate because they don't want to be told or acknowledge they are close to the moment of death. I think it would be very difficult to find subjects.
    Plus, Although I myself DO believe in the Soul (I prefer the word "spirit" though), I am not sure that the experiment of attempting to 'weigh' the body at the moment of death and if it changes that would be definitive proof. There are too many variables to figure out such as is there a simple muscular-skeletal thing that happens when the body goes fully relaxed at that time.... or to make sure it could not possibly be something else. It would be interesting to work on that experiment, from that angle of what all could be happening physically to cause a drop or change in weight; not the part of the experiment where a dying person is treated like a subject....and they deserve the best possible caring instead.
    Perhaps hospitals could begin placing active scales in the beds that are calibrated and constantly working and recording changes. I do know that new hospital beds have something like that so they can constantly watch that and do not have to get the patient up to register their weight.
    But anyways, I am going to look on youtube for that video I was referring to.

  3. Thanks, Karen. I stand by my statement that "Not a single supernatural claim has withstood (scientific) scrutiny. Ever." This is the perfect opportunity for you to prove me wrong. I look forward to reviewing videos or any other evidence you have. Could be fun!