Parallel Evolution, 1920-60
The rapidly changing medical, social, and political landscape of the 1920s to the 1960s challenged chiropractic’s ability to adapt and thus to survive. On the one hand, an excessive reliance on beliefs and theories developed in the 1890s might render this system anachronistic.
On the other, chiropractic risked losing its distinctive character if it underwent radical reform and became “medicalized.” An examination of the changing role of technology in chiropractic, the modification of its criticisms of the germ theory, and the stiffening of chiropractic educational standards will demonstrate how it successfully responded to the challenge.Mixers versus Straights: Technology in Chiropractic
At the 1924 annual homecoming of the P.S.C., B. J. Palmer made a startling announcement: Henceforth the “neurocalometer” would be a vital component of the chiropractic system. Touted as a breakthrough for scientific chiropractic, the neurocalometer was a machine designed to help diagnose subluxations by registering differences in heat alongside the spinal column. It could be obtained only from the Palmer School for $500 and a $1.00 per month service charge.
Chiropractors were stunned, and with good reason. Since chiropractic’s earliest years, the use of technology had engendered enormous controversy. B. J. Palmer himself had argued strenuously that diagnosis and treatment should be performed only by manual manipulation. In fact, he claimed that the Palmer School taught chiropractic “P, S, and U” - pure, straight, and unadulterated - and scornfully labeled any practitioners who utilized other modalities as “mixers.”
For “straight” practitioners, chiropractic was a natural system of healing that allowed the body to manifest its intrinsic restorative powers. The use of machines implied that natural methods of diagnosis and treatment were inadequate.
By avoiding the use of machines, chiropractic buttressed its argument that it was fundamentally different from medicine, which relied increasingly on new technologies during the early years of the twentieth century. By rejecting technology, chiropractic also avoided regulation under medical practice laws.On a deeper level, the rejection of technology reflected the ambivalence of many Americans toward machines. Machines created change, and although change could be positive, it also caused Xmcertainty and upheaval. As industrialization proceeded during the late nineteenth and early twentieth centuries, many were uncertain whether the changes induced by modem technology were improvements, and straight chiropractors were able to tap into this wellspring of concern.
Conversely, the “mixers” utilized the positive image of technology to foster their growth. Machines were new and exciting, the wave of the future, and chiropractic needed to take advantage of modem technology in order to see that future. Many mixer schools, led by the National School of Chiropractic of Chicago, advocated using diagnostic and therapeutic adjuncts. As if to emphasize its differences with the straight chiropractors, the National School of Chiropractic had several physician-chiropractors on its faculty by 1916.
As the leader of straight chiropractic, B. J. Palmer had rarely declined an opportunity to ridicule the mixers. When he suddenly declared that the neurocalometer was not only acceptable but central to chiropractic practice, many ardent supporters were outraged. Four key members of the Palmer School faculty resigned. Palmer was accused of betraying his colleagues, and because the neurocalometer could be obtained only from Palmer, many thought he had been motivated by greed. The neurocalometer debate signaled an important change in chiropractic. Although advocates of straight practice continued to play an important role, their strength waned and gradually most chiropractors incorporated adjuncts into their practice.
The introduction of the neurocalometer in 1924 reflected a shift in U.S. attitudes toward technology, for the prosperity of the 1920s had eased earlier fears about it while highlighting its economic benefits. B. J. Palmer’s acceptance of machines is best seen in this light. As machines became firmly enmeshed in the fabric of U.S. life, it became untenable for this system of healing to reject them, although the distinction between straights and mixers, while increasingly blurred, would endure for some time.The Germ Theory and Chiropractic
Another milestone in the evolution of chiropractic was an increasing acceptance of the germ theory of disease. At first many chiropractors had rejected the notion that bacteria could cause disease. However, as germ theory achieved widespread acceptance, they realized that rejection of the association between bacteria and disease would make chiropractic
seem retrogressive. Accordingly, chiropractors no longer insisted that bacteria could not cause disease but instead argued that bacterial infection was a secondary phenomenon that occurred only in persons whose ability to resist disease had been vitiated by a spinal subluxation. This stance allowed chiropractors to highlight a major problem with germ theory: If the key to disease was simply infection with pathogenic organisms, why didn’t everyone exposed to a germ become ill? Or why did some people infected with the same organism die and others experience only a mild illness? By emphasizing resistance as the key to health and disease, chiropractors retained their explanatory model while continuing to challenge formal medicine.
Educational Reform in Chiropractic
Education provides another window on the development of this system of healing. During the earliest years of chiropractic, disagreements developed over what, if any, formal education should be required. One group of practitioners, commonly referred to as “field-men,” opposed any formal training, arguing that it was elitist.
They felt that chiropractors should reject the medical model of education with its emphasis on “book-learning” and instead rely on the practical training that an apprenticeship provided. Although the field-men’s arguments were heavily influenced by their concern that licensing legislation would exclude practitioners who lacked a chiropractic diploma, their stance also highlighted the ideological commitment to egalitarianism that many chiropractors felt their field should embody.Competition among chiropractic colleges also inhibited the adoption of educational standards. Each institution vied for students and wanted to be recognized as the “true” standard bearer of the profession. Each had a slightly different definition of chiropractic, typically dividing along the “mixer-straight” axis. Each wanted its own diploma to be the exclusive prerequisite for a chiropractic license. Attempts to block the legislative recognition of rivals occasionally resulted in open warfare among the schools.
Despite this contentious beginning, the conviction that there was a need for minimal educational standards gradually gained wider acceptance. Exposes of mail-order chiropractic “colleges” had tarnished the reputation of the entire profession, and the dramatic reform of medical education in the early twentieth century had opened a wide gap between the training standards of regular physicians and those of chiropractors. Physicians exploited this difference by frequently ridiculing the standards of chiropractic schools, many of which had curricula that required only 18 months of schooling.
Chiropractors responded by gradually embracing a professional model of training and reducing 79 schools in 1920 to only 21 by 1932. Those that remained increased the period of training and strengthened their faculties, and schools that had previously emphasized how rapidly one could become a chiropractor increasingly stressed the advantages of their clinical facilities, eminent faculty, and comprehensive curricula.
In 1935 the National Chiropractic Association (NCA), the mixers’ professional organization, established a Commission on Educational Standards. This led to the adoption of formal accrediting procedures, and the International Chiropractors Association, the straight chiropractics’ representative, followed suit. Spurred by the tireless efforts of John Nugent, director of education of the NCA, a continual strengthening of educational standards occurred in the 1940s and 1950s.The adoption of technology, reconceptualization of the relationship between bacteria and disease, and educational reform were all ways in which chiropractors responded to a changing environment. Chiropractic’s ability to retain its distinct identity while undergoing this evolution helps explain how it has avoided the fate of other alternative healing sects. The evolutionary trajectories of medicine and chiropractic can be conceived of as two parallel lines, and the ability of the latter to maintain a constant distance from medicine is perhaps the most remarkable quality in its historical development. If the distance between the two professions had narrowed, as in the case of homeopathy and osteopathy, chiropractic would have risked losing its identity. If the distance had widened, chiropractic would have risked becoming anachronistic. Instead, it flourished as it adroitly maneuvered between the Scylla of convergence and the Charybdis of divergence.