Dr. Duncan MacDougall (died 15th October 1920, aged 54) was an early 20th century physician in Haverhill, Massachusetts who sought to measure the mass purportedly lost by a human body when the soul departed the body upon death.

In 1907, MacDougall weighed six patients while they were in the process of dying (no detail is given to how this occurred or at what intervals the patients were weighed). He took his results (a varying amount of perceived mass loss in most of the six cases) to support his hypothesis that the soul had mass, and when the soul departed the body, so did this mass. MacDougall also measured fifteen dogs in similar circumstances and reported the results as "uniformly negative," with no perceived change in mass. He took these results as confirmation that the soul had weight, and that dogs did not have souls. MacDougall's complaints about not being able to find dogs dying of the natural causes that would have been ideal have led at least one author to conjecture that he was in fact poisoning dogs to conduct these experiments. In March 1907, accounts of MacDougall's experiments were published in the New York Times and the medical journal American Medicine.

Although generally regarded either as meaningless or considered to have had little if any scientific merit, MacDougall's finding that the human soul weighed 21 grams has become a meme in the public consciousness. It lent itself to the title of the film 21 Grams. In the end, however, his practices were considered fallible due to shaky methods and small sample size. Scientists disregard his research into this field due to allegations of bias.

References

External links

• Summary of MacDougall's research at Snopes.com
• Full text of MacDougall's research
• Related paper by Lewiss E. Hollander, Jr. showing transient weight increase at time of death for sheep.