August 18 2008
Ah, the mainstream media doing what it does best: reporting science.
This is a pretty interesting concept.
As the story goes, a doctor named Duncan MacDougall proved that the soul exists because he found that people weigh less (about 21 grams) after they die than they did just before death. These results were reported in the New York Times numerous times after the study was performed…in 1907.
I guess science reporting was as crappy 100 years ago as it is now. But, rather than just dismiss this out of hand as we probably should, let’s analyze it a bit.
First, it’s pretty lazy logical thinking to assume that, even if there IS a difference in weight, that it automatically means that it’s the result of the soul leaving the body. It’s only 21 grams (or 3/4 of an ounce), so we’re not talking about a whole lot of weight. I’m no doctor, but I can think of a few ways that this could be attributed to something besides a phenomenon that has never been proven to exist.
- Breath leaving the body. Contrary to popular belief, air DOES have weight, though it’s very low. When a person dies, their lungs deflate, and a lot of air is expelled from the body. I wouldn’t even bring this up, except for the fact that the missing weight is only 21 grams. It also goes hand-in-hand with my next idea:
- Moisture leaving the body. Your breath has moisture in it, after all. Just breathe on a piece of glass and it’ll fog up. When the breath leaves the body, it takes some moisture with it. I’m guessing that the moisture is probably heavier than the actual air.
- Snopes has what I think is the most reasonable explanation, from the American Medicine journal:
“…MacDougall…failed to take into account the sudden rise in body temperature at death when the blood stops being air-cooled via its circulation through the lungs….[The] sweating and moisture evaporation caused by this rise in body temperature would account both for the drop in the men’s weight and the dogs’ failure to register one.”
More on the dogs later.
(I feel like a real reporter or something. I just used a quote from a medical journal.)
- Were such large scales in 1907 even able to measure with such accuracy? Maybe I’m underestimating the technology of the time. MacDougall says in his paper that his “scales were sensitive to two-tenths of an ounce”. That doesn’t seem accurate enough to me, especially considering how difficult it must be to balance a body on what must be a pretty large scale.
Anyway, we’re still talking about 21 grams here.
Let’s examine the study itself now. Was the study well done? What was the sample size?
Six. He weighed six people before and after they died. This is nowhere near a sufficient sample size for any scientific or medical study. Except that two of the six subjects weren’t able to be weighed, so really it’s just four people in this study. Only one of the 4 actually lost 3/4 of an ounce, and the others were far less exact. This study is quite a mess.
Ok, I think I’ve beaten this into the ground. However, MacDougall still may have stumbled upon something here. Maybe somebody has duplicated his results over the years. Well, I did do some limited searching for similar studies, and I didn’t find any evidence that supports MacDougall’s claims, although that doesn’t mean that the evidence isn’t out there. In fact, I did find one study that showed that the body actually increased in weight after death, but it was a pretty lousy study too, and they were weighing sheep.
You know, these days it would be very easy to perform our own scientific study of this “phenomenon”. Some modern hospital beds have built-in scales and automatic monitoring that could easily detect this weight loss, if it’s happening. It should be fairly easy to look at the weight logs of a few thousand people who died in a hospital equipped with these beds and figure out if they’re losing any weight when they die.
Of course, even if you established that they do, you still need to establish that it’s linked to the soul leaving the body, and to do that you would first need to prove that the soul actually exists. Good luck with that, and remember Occam’s Razor.
On a related note, I just sent this subject in to Skeptoid as a suggestion for a future episode. I’d love to hear Dunning’s take on it, but I’m sure he’s got much more important stories to tackle.