I have a bet with my wife that I need to resolve.  In attempting to
prove that there is a soul, she has stated that there are studies that
have shown that a human body weighs less after someone has died.  That
if you weighed someone while alive and immediately after being
pronounced dead, that the dead body will weigh more (taking into
account any loss of waste products or other obvious physical mass).  I
contend that is ridiculous.

I would like a list of any studies that have been made on this urban
myth in order to dispel the notion.  If any research has been
produced, published or cited on the web, I would like a referecne to
it.

Hello misterfine,

The belief that the human body loses weight -- soul-weight, perhaps --
upon the moment of death was popularized a couple of years ago by the
film "21 Grams," and is based on results of experiments by Dr. Duncan
MacDougall published in 1907.  This belief is apparently unproven.

"Soul Man" (Last updated 27 October 2003)
Snopes.com
http://www.snopes.com/religion/soulweight.asp

"Take 21g idea with 0.0015mg of salt," by Ian Sample (February 21,
2004) [including views of Robert Stern, a pathologist at the
University of California, San Francisco, which dispute Mr.
MacDougall's hypothesis]
The Age
http://www.theage.com.au/articles/2004/02/20/1077072838871.html

"Great Moments in Science -- 21 Grams," by Karl S. Kruszelnicki (2004)
ABC [Australia]
http://www.abc.net.au/science/k2/moments/s1105956.htm

Dr. MacDougall's findings are reprinted at:

"Hypothesis Concerning Soul Substance Together with Experimental
Evidence of The Existence of Such Substance," by Duncan MacDougall,
M.D. of Haverhill, Mass (posted by Dave Oester, 1997)
International Ghost Hunters Society
http://www.ghostweb.com/soul.html

An editorial last year in the British Journal of Sports Medicine takes
issue with the methodology of Dr. MacDougall's study.

"Blinded by the light" by P McCrory (2004;38:381)
British Journal of Sports Medicine
http://bjsm.bmjjournals.com/cgi/content/full/38/4/381

A 2001 paper asserted transient weight gains in animals at the moment
of death.  (If true, this would be consistent with the belief in "dead
weight" noted in the Snopes article.)

"Unexplained Weight Gain Transients at the Moment of Death," by Lewis
E. Hollander Jr. (Journal of Scientific Exploration, Vol. 15, No. 4,
pp. 495?500, 2001)
Society for Scientific Exploration
http://www.scientificexploration.org/jse/articles/pdf/15.4_hollander.pdf

For comments to a previous question on this topic, see:

"Unexplained Weight Loss at Moment of Death"
Google Answers
http://answers.google.com/answers/threadview?id=343392

- justaskscott


Search strategy --

Searched on Google Web and Google Scholar for the following terms,
individually or in combinations:

"21 grams"
snopes
"duncan macdougall"
"dead weight"
"hypothesis concerning soul substance"

It's my understanding that at the "moment of death"?there is some
uncertainty as to what that is?all the muscles relax, the pores open,
residual sweat is released, the body temperature rises slightly.
Assuming the body is lightly covered with sheets, this could well
account for the rapid loss of an ounce or two of weight, as the film
of sweat  flash-evaporates and rises from the warm body.

Whether or not this is explanation is consistent with the 'rapid'
change in weight recorded by MacDougall in 1907 (rapid enough to
register a noise with no rebound as the balance beam lowered) would be
difficult to say without a repetition of the experiment with modern
equipment. But it nicely corresponds with the lack of loss in dogs.
Canines, and most fur-bearing animals have no sweat glands over their
bodies.

Naturally we would want to see the experiment repeated with a light
polyethelene sheet draping most of the body, or a hydrophilic fabric.
The hypothesized warm water-vapour would be retained long enough to
prevent weight-loss. As has been mentioned elsewhere, modern ethical
considerations would preclude such an experiment, although many have
expressed an interest and willingness to take part.

My only misgivings would be the usual round of acrimony between
skeptics and believers as to purported experimental bungling, lack of
'controls', and the unrepeatability that plagues so many of even the
most innocuous, carefully conducted, and uncontroversial of
experiments.