In some studies, individual biorhythmic cycles are called one of the factors that affect unsafe behaviors and occupational accidents. Biorhythm can describe energy levels and performance capabilities in physical, emotional, and intellectual aspects. Several authors have suggested the critical days of biorhythm as a possible cause of industrial accidents, although the empirical evidence is confusing. This study examined all industry-related accidents in a large Australian wood milling organization over a period of 15 months to see if the implicit relationships existed.
A variety of definitions of critical days of biorhythms and types of accidents were analyzed, but no significant results were obtained, suggesting that the proposed theory was not maintained in this case. The general concept of biorhythm, its validity and its application in the prevention of accidents and in the prediction of performance are discussed. In the 1960s, 70s and 80s, biorhythms had gained more popularity. From books to biorhythm calculators, many people had prescribed the idea.
Articles on biorhythms are found in scientific journals, but most studies (99 out of 13) indicate that biorhythms are not valid and that they are not better at predicting than chance. Biorhythm theory is the pseudoscientific idea that our daily life is significantly affected by rhythmic cycles with periods of exactly 23, 28 and 33 days, typically a 23-day physical cycle, a 28-day emotional cycle and a 33-day intellectual cycle. The idea was developed by Wilhelm Fliess in the late 19th century and became popular in the United States in the late 1970s. The proposal has been independently tested and, consistently, no validity has been found for it.
The 23-day and 28-day rhythms used by biorhythmists were first devised in the late 19th century by Wilhelm Fliess, a Berlin doctor and friend of Sigmund Freud. Evidence of the synchronization of this biorhythm is preserved in tooth enamel as the periodicity of Retzius lines. Biorhythm programs were a common application on personal computers; and in the late 1970s, there were also portable biorhythm calculators on the market, Kosmos 1 and Casio Biolator. The word “biorhythm” derives from the Greek word “Bios”, which means life and “rhythm”, which means to flow with a regular movement.
It is suggested that drivers have a higher risk of having an accident on “critical” days in any of their physical, emotional or intellectual biorhythm cycles. In the early 1900s, a professor named Hermann Swoboda claimed to have independently devised biorhythms, and then another professor named Alfred Teltscher noticed that students' academic success was executed in 33-day cycles. A 1978 study on the incidence of industrial accidents found no empirical or theoretical support for the biorhythm model. This chapter presents a new methodology based on a probabilistic approach to biorhythmic analysis in an attempt to prevent aviation accidents.
The practice of consulting biorhythms was popularized in the 1970s by a series of books by Bernard Gittelson, including Biorhythm A Personal Science, Biorhythm Charts of the Famous and Infamous, and Biorhythm Sports Forecasting. Without them, biorhythms became another pseudoscientific statement that people are willing to accept without the required evidence. The validation of a plane crash due to a biorhythm is explained in this chapter taking into account the maximum performance demand and the different standard deviations in the performance capacity of each pilot. Biorhythm theory mainly uses scientific methods to trace the rhythms or cycles that affect the inner workings of the body and human behavior.