2019/04/03 by Douglas J. Lanska · 1 citation
Medicine · Neuroscience · Psychology · #Complementary and Alternative Medicine Studies #Pain Management and Placebo Effect #Academic and Historical Perspectives in Psychology
paper · doi:10.1080/0964704x.2019.1589833
openalex publication_date 2019/04/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
From 1799 to 1801, with the instigation of John Haygarth, physicians in England evaluated the claims of Elisha and Benjamin Perkins that their patented "metallic tractors" could cure a wide variety of disorders. Previous therapies were typically judged based on experience and authority, whereas Perkinism was evaluated using a series of clinical trials of varying methodological sophistication, most employing sham instruments (all but those involving infants or horses), with a variety of trial designs, inconsistent use of contemporary controls, and different approaches to blinding subjects to the treatment administered. Haygarth and his colleagues collectively demonstrated that tractors and sham instruments produced equivalent effects in adults, and, by inference, that the tractors had no special therapeutic properties. Other trials using only genuine tractors demonstrated no effects in infants and horses, subjects who could not reasonably be influenced by suggestion and the imagination. These collective results provided strong support for the rival hypothesis that the observed effects were due to suggestion and the imagination of the subjects. Despite fallacy-laden counterattacks and counterarguments from Benjamin Perkins and his supporters, the trials eroded support for this therapy and led to abandonment of the "Metallic Practice" as a treatment in Britain and elsewhere.