This post is coauthored by Josh Levy, historian of science and technology, and Jackie Katz, 2022 Albert Einstein Distinguished Educator Fellow. It is one in a series focused on teaching scientific literacy by assessing historical examples of pseudoscience.
What’s the difference between science and pseudoscience? Designating a discipline as a science indicates that it involves the study of observable, natural phenomena that can be better understood through tests that produce consistent and predictable results. The findings of these tests must always be considered tentative. If any of the above tenets are absent, the research is pseudoscientific.
Spiritualism, the belief that consciousness is maintained after death in the form of a spirit, gained many supporters in the United States between the 1840s and 1920s. Psychic mediums were individuals who claimed to communicate with spirits during a séance. Kate and Maggie Fox, known as the Fox Sisters, are largely credited with starting the movement in 1848, when they first appeared to communicate with spirits in their upstate New York home. As word of this movement spread to major cities in the US, some raised concerns about the validity of the communications. Others, however, were looking for scientific proof that mediums like the Fox Sisters were communing with spirits rather than perpetrating a fraud.
A newspaper article from the New York Tribune (1919) outlines Sir William Crookes’ efforts to provide scientific tests for spiritualism. To get students thinking about testing spiritualism, present them with the experiment image from this article. Without providing information beyond the image, support them as they observe, reflect and question using the Primary Source Analysis Tool. Ask them to share predictions on how each piece of equipment might work to verify communication with spirits. Then allow time to read the text of the article to test their predictions. Were they able to determine how Crookes was measuring “the psychic force” of the medium?
Crookes was not the only person who took an interest in proving the presence of a psychic force in self-proclaimed mediums. In the 1880s, the Seybert Commission was established at the University of Pennsylvania to identify scientific evidence for spiritualism. Ask students to read an excerpt from the commission’s 1887 report (pages 27-28) and summarize the tests that were conducted.
Once students have reviewed the work of Crookes and the Seybert Commission, ask them to assess the scientific validity of the various tests. It might be useful to review the components of a scientific experiment with students prior to their assessment (i.e. controlled variables, objective observations, large sample size). Students may note that all tests failed to have control groups for comparison, and the Seybert Commission did not produce objective observations. Challenge students to think of a scientific test for spiritualism. Can they come up with one? If not, why? The answers to these questions will likely lead students to classify spiritualism as pseudoscience.
These sources may also trigger some conversations about the effect societal norms can have on science. Have students review the names of the members of the Seybert Commission. What do they notice about these individuals? What might this tell us about society’s definition of “experts?” If students skim through other experimental notes in the appendix of the report they may notice majority of the mediums are female. Students can also examine physician Edward H. Clark’s 1873 argument that women and girls were physiologically unsuited for rigorous academic study of any kind (pages 112-115). Could this have affected the degree to which mediums were trusted?
By discussing pseudoscientific concepts, students can build their scientific literacy and critical thinking skills, helping them consume the news of today with more confidence. Pseudoscientific concepts also provide an opportunity to have difficult conversations regarding bias in science, and its social impacts.
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