21 grams experiment

The experiment is widely regarded as flawed and unscientific due to the small sample size, the methods used, as well as the fact only one of the six subjects met the hypothesis.

In 1901, Duncan MacDougall, a physician from Haverhill, Massachusetts, who wished to scientifically determine if a soul had weight, identified six patients in nursing homes whose deaths were imminent.

MacDougall specifically chose people who were suffering from conditions that caused physical exhaustion, as he needed the patients to remain still when they died to measure them accurately.

[4][5] Before MacDougall was able to publish the results of his experiments, The New York Times broke the story in an article titled "Soul has Weight, Physician Thinks".

[9] Noting that only one of the six patients measured supported the hypothesis, Karl Kruszelnicki has stated the experiment is a case of selective reporting, as MacDougall ignored the majority of the results.

[1] Physicist Robert L. Park has written that MacDougall's experiments "are not regarded today as having any scientific merit",[5] and psychologist Bruce Hood wrote that "because the weight loss was not reliable or replicable, his findings were unscientific".

[3][4] In 1911, The New York Times reported that MacDougall was hoping to run experiments to take photos of souls, but he appears to not have continued any further research into the area and died in 1920.

Ishida found Hollander's statement of a transient gain of weight was "not an appropriate expression of the experimental result", though he admitted "the cause of the force event remains to be explained".

[11] Similarly inspired by MacDougall's research, physician Gerard Nahum proposed in 2005 a follow-up experiment, based on utilizing an array of electromagnetic detectors to try to pick up any type of escaping energy at the moment of death.

[17] Songs entitled "21 Grams" which reference the weight of a soul have been released by Looptroop Rockers (2005), Niykee Heaton (2015),[18] Fedez (2015), August Burns Red (2015), Thundamentals (2017), Arena (2022), and Klan featuring Madeline Juno (2024).