May 17, 2023

Many today are aware of the theory that moldy bread caused the strange behavior that triggered the witchcraft panic in Salem in 1692. Known as the “ergot theory” this idea was put forward by Linnda Caporael in the April, 1976 edition of Science magazine

Ergot is a fungus that, under the right circumstances, grows on rye. Those who consume this substance can become very ill, experiencing what is known as ergotism. There are two manifestations of ergotism; gangrenous and convulsive. Those who suffer from convulsive ergotism experience “delirium and hallucinations, accompanied by rigid, extremely painful flexed limbs, muscle spasms, convulsions, and severe diarrhea.” (Paul Schiff, 2006). According to Caporael, this could explain the behavior exhibited by the afflicted girls during the Salem witch trials, including their violent convulsions and the many stories of spectral witches and ghostly figures.

A unique theory for the time, this hypothesis was almost immediately disproven by Salem witch trials scholars. At the time of publication, the author of this article was an undergraduate student taking a required history course. In her excellent lecture “The Salem Witch Trials and Ergot, the ‘Moldy Bread’ Hypothesis,” historian Margot Burns describes a conversation with Linnda Caporael about the publication of this article. As Linnda recalled, she sent in this article and by chance it was published.

Shortly after the appearance of this article, Nicholas Spanos and Jack Gottieb published a full review of the theory also in Science magazine. In their response, Spanos and Gottieb firmly concluded:

“The available evidence does not support the hypothesis that ergot poisoning played a role in the Salem crisis. The general features of the crisis did not resemble an ergotism epidemic. The symptoms of the afflicted girls and of the other witnesses were not those of convulsive ergotism. And the abrupt ending of the crisis, and the remorse and second thoughts of those who judged and testified against the accused, can be explained without recourse to the ergotism hypothesis” (Nicholas Spanos & Jack Gottieb, 1394).

There are a few important criticisms of the ergot theory. To start, an entire family would consume the same source of rye, yet only one or two people per household became sick with the mysterious illness in almost every recorded case in 1692. For example, in the Parris home (the site where the illness began), of a household with four adults (Reverend Parris, his wife Elizabeth, Tituba and her husband John Indian) and four children, only two people became sick, 9-year-old Betty Parris and 11-year-old Abigail Williams. This would be a common pattern throughout the witchcraft panic.

We also see this illness (what historians call “the affliction”) spread well beyond the boundaries of Salem—a detail that Caporeal failed to account for in her original article. In fact, Andover, located approximately 20 miles to the northwest of Salem, had the highest rate of accusations and numerous locally afflicted witnesses. Given that the emergence of the affliction was sporadic and spread far beyond Salem into the surrounding communities, it does not make sense to conclude the illness was caused by spoiled crops.

Finally, we also see numerous cases of what appear to be outright fakery in the contemporary records. For example, the testimony of Daniel Elliott in favor of Elizabeth Proctor describes a March incident where an afflicted witness claimed to see a specter but admitted “she did it for sport, they must have some sport.” (Bernard Rosenthal, 537) This is not the only example of a primary source document which hints that some of the afflicted were not truly ill in 1692.

Despite the clear response from historians of the Salem trials, the ergot theory spread throughout the United States over the next several years. According to Burns, the immediate and persistent interest in Caporael’s theory was in part due to the cultural fascination with LSD during this period. The drug was becoming increasingly popular and there was growing alarm about its use. In the wake of Caproael’s article, the theory was discussed by numerous major national publications such the New York Times and the Washington Post. As LSD is produced from an ergot alkaloid, these news stories appeared with attractive headlines (i.e. “Salem Witch Hunt: Just a Bad LSD Trip” or “It was a Bad Trip in Salem”), each of which pronounced the Salem witch trials were likely caused by this psychedelic substance. After this immediate wave of reporting, the story was picked up by national wire services, resulting in a further explosion of coverage (over 200 articles across the United States, says Burns).

The allure of these flashy headlines never truly diminished and the ergot theory remains remarkably prevalent. Television shows, documentaries, blogs, articles, and podcasts continue to present this as a likely theory. Moreover, ergotism has been, and in some cases, continues to be, included in school curriculums as an explanation for the Salem witch trials. It seems this is a theory that simply will not fade away, remaining ever present in popular discourse of the witchcraft trials.

When considering the question “What caused the Salem witch trials,” it is important to remember there is a danger in seeking the elusive, singular, all-encompassing explanation. It would be much easier to explain the Salem witch trials if we had a clear, scientific explanation. It is tempting to view this episode as the simple result of an uncontrollable, biological reaction, one which was incomprehensible to the residents of seventeenth-century New England. The truth of the matter is far more complex. It is very possible there was no singular explanation and a variety of factors led to the rise and decline of this strange behavior. Moreover, if we refrain from viewing these events as nothing more than a puzzling anomaly from a distant time, one that was caused by a poisoned crop, or a desire to steal land, or unenlightened superstition, we begin to understand the Salem witch hunt as yet another example of an enduring pattern of human behavior. In this light, we can find many familiar stories; the tendency to scapegoat during periods of increased fear, the loss of control and order during a time of perceived danger, the fear of what goes bump in the night. Only by considering our similarities, rather than our differences, do the events of 1692 begin to come into sharper relief, reminding us that these events have important lessons and warnings for those who care to listen.




Margot Burns, “The Salem Witchcraft Trials and Ergot, the ‘Moldy Bread’ Hypothesis,” History Camp Boston, 2019,

Linnda R. Caporael, “Ergotism: The Satan Loosed in Salem?” Science, Vol. 192, No. 4234 (April 2, 1976),

Jack Gottlieb and Nicholas P. Spanos, Ergotism and the Salem Village Witch Trials, Science, Vol. 194, No. 4272 (December 24, 1976),

Bernard Rosenthal, ed. “Testimony of Daniel Elliott for Elizabeth Proctor,” in Records of the Salem Witch-Hunt, 2009.

Paul L. Schiff, Jr., “Ergot and Its Alkaloids,” American Journal of Pharmaceutical Educational, National Library of Medicine, Volume 70, No. 5 (October 15, 2006),


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