History and Controversy of Biorhythms: From Viennese Theory to Scientific Debunking
The history of biorhythms is a fascinating story about how ideas spread, persist, and resist refutation — even when the evidence is clear. It is also the story of two respectable Viennese physicians whose theories took on a life of their own far beyond what they could have imagined.
The Origins: Vienna, Late 19th Century
Wilhelm Fliess: The Physician with Two Rhythms
Wilhelm Fliess (1858-1928) was a Berlin ear-nose-throat physician and close associate of Sigmund Freud — the two men maintained an intense correspondence and intellectual friendship for several years. Fliess was brilliant, original, and deeply convinced of his theories.
In the 1890s, Fliess developed his theory of the "periodicity of life." Observing his patients, he believed he could identify two fundamental rhythms in the human body:
- A 23-day cycle that he associated with masculine vitality
- A 28-day cycle that he associated with feminine vitality
His logic was that these cycles applied to all humans, regardless of biological sex. The male body had a "feminine element" and vice versa — a forward-thinking idea for the era, and consistent with Freud's explorations of psychological bisexuality.
Fliess published his theories in two main works: Der Ablauf des Lebens (The Course of Life, 1906) and Vom Leben und vom Tod (Of Life and Death, 1909). These were taken seriously by some of his contemporaries, including Freud himself, who saw in them a possible biological foundation for psychoanalysis.
Hermann Swoboda: The Viennese Independence
Hermann Swoboda (1873-1963), a Viennese psychologist, independently and simultaneously developed a similar theory, identifying the same two cycles of 23 and 28 days. He published his ideas in Die Perioden des menschlichen Organismus (1904) and Studien zur Grundlegung der Psychologie (1905).
The priority of discovery became the subject of a bitter controversy between Fliess and Swoboda, each claiming precedence. This dispute lasted for years and was never truly resolved — a symptom of the difficulty of establishing intellectual paternity for an idea "in the air."
Friedrich Teltscher: Adding the Intellectual Cycle
The third pillar of biorhythm theory was provided by Friedrich Teltscher (1872-1930), an Austrian engineer and professor at Innsbruck. In the 1920s, Teltscher analyzed the scholastic and examination performances of his students and believed he could identify a 33-day cycle influencing intellectual capacities.
It was with Teltscher that the biorhythm trilogy was complete: 23 (physical), 28 (emotional), 33 (intellectual). None of the three men directly collaborated with the other two — their contributions were retrospectively integrated into a unified theory.
Popularization: Decades of Enthusiasm
The 1920s-1950s: An Idea in Gestation
The decades following the original publications saw biorhythms circulating in European academic and popular circles, without ever reaching a wide audience. Books were published, articles written, but the movement remained limited to a specialized public.
World War II interrupted the dissemination of ideas from the German-speaking world. After 1945, intellectual reconstruction and the reclassification of "German" post-Nazi ideas created a period of relative dormancy for biorhythms.
The 1960s-1980s: The Great Popular Wave
The real popularization of biorhythms occurred in the 1960s-70s, driven by three converging phenomena:
1. The Western New Age Movement The counter-culture of the 1960s-70s created demand for alternative self-knowledge systems — astrology, numerology, I Ching, crystals, and biorhythms. Biorhythms had the advantage of being presentable as "scientific" thanks to their mathematical basis, while promising the same mystical self-knowledge as other esoteric systems.
2. Popularity in Japan Japan adopted biorhythms with particular enthusiasm. Major Japanese corporations — including some airlines and industrial companies — implemented biorhythm tracking systems for their employees, with the goal of reducing workplace accidents during "critical days." Studies were conducted (and sometimes published in English) claiming a correlation between critical days and accidents.
3. The Advent of Microcomputing With the arrival of accessible scientific calculators (mid-1970s) and then the first microcomputers, calculating biorhythms became trivial. Programs for Apple II, TRS-80, and Commodore 64 circulated in computer clubs. Biorhythms were a perfect use case for the first "personal computers": a simple algorithm, a graphical result, an immediately perceived utility.
Books like George Thommen's Is This Your Day? (1964, reprinted several times) reached the American public at large. Mechanical biorhythm calculators (calculation wheels) were sold in pharmacies and stationery stores. Biorhythm columns appeared in some newspapers, alongside horoscopes.
Industrial and Aviation Use: The Controversial Studies
Japanese Aviation
Several Japanese airlines reported having studied correlations between biorhythms and incidents. All Nippon Airways claimed to have reduced pilot accidents by warning them of their critical days. These claims circulated widely in popular biorhythm literature as evidence of their effectiveness.
The problem: these studies were generally not published in peer-reviewed journals, did not control for confounding factors, and often used methodological designs that would produce positive results even with random data (cherry-picking incidents corresponding to critical days).
Swiss Industry
Switzerland was another notable terrain of industrial adoption. The SBB company (Swiss Federal Railways) and other Swiss industrial companies experimented with biorhythm programs in the 1970s-80s to manage sensitive staff assignments.
Scientific Debunking: The Meta-Analyses
Terence Hines: The Definitive Refutation
The most comprehensive and widely cited study on biorhythms is the work of Terence Hines, a psychologist at Pace University in New York. His 1998 meta-analysis, published in Psychological Reports, reviewed dozens of biorhythm studies and concluded:
"There is no evidence that the theory of biorhythms is true."
Hines analyzed studies on:
- Athletic performance (competitions, personal records)
- Workplace and traffic accidents
- Cognitive performance (standardized tests)
- Medical incidents
- Mortality
In no category did the data show a significant correlation between calculated biorhythmic phases and measured outcomes. Specifically, "critical days" did not correspond to a higher accident rate than chance.
Methodological Problems in Positive Studies
Studies claiming to have found biorhythmic effects generally suffered from several problems:
Confirmation bias: observers who believed in biorhythms were more likely to notice and report confirming coincidences.
P-hacking: with three different cycles (and therefore six high phases and six low phases, plus approximately twelve critical days per cycle), there are enough "predictions" that a fraction will coincidentally land on real events.
Lack of controls: industrial studies did not control for fatigue, working hours, experience, environmental and seasonal factors.
Publication bias: studies finding no effect were less likely to be published or cited.
Other Key Studies
- Wolcott, McNeely, and Rose (1977): analysis of 4,000 workplace accidents — no correlation with biorhythms
- Khalil and Kurucz (1977): analysis of 112 fatal pilot accidents — no excess of critical days
- Bainbridge (1978): meta-analysis of 25 studies — null effect
Why Biorhythms Persisted: Sociology of a Refuted Idea
If the evidence is so clear, why do biorhythms continue to have followers in 2026? Several sociological factors explain this persistence:
The Barnum/Forer Effect
Biorhythmic descriptions are sufficiently vague that everyone can apply them to their own experience. Saying that your physical cycle is "in high phase" corresponds to something for almost anyone on any given day — we all have moments when we feel physically well.
The Rationality of Self-Observation
Using biorhythms as a pretext for self-observation is not irrational. If someone starts keeping an energy journal because they are tracking their biorhythms, they will discover real patterns — not related to the calculated biorhythms, but to their sleep, diet, and stress. A false system can produce useful behavior.
The Need for Control
Human beings have a fundamental need for predictability and control. A system that promises to predict your "good days" and "bad days" addresses a deep psychological need, regardless of its empirical validity.
The Persistence of the Graphical Form
The biorhythm graph — with its colored curves rising and falling — is visually convincing and intuitive. It resembles a medical instrument. Its visual form confers an authority its substance does not justify.
Cultural Impact
Despite (or because of) their pseudoscience status, biorhythms have left a notable cultural trace:
- Music: The Alan Parsons Project released the album Pyramid (1978) influenced by esoteric themes including biorhythms
- Film and TV: mentions in popular shows of the 1970s-80s
- Dedicated calculators: Casio and other manufacturers sold biorhythm calculators in Japan until the 1990s
- Mobile apps: dozens of iOS/Android apps continue to calculate biorhythms in 2026, with millions of cumulative downloads
Current Status (2026)
Biorhythms are today classified among pseudosciences, alongside astrology, numerology, and graphology. No serious scientific organization endorses them.
However, their indirect legacy is interesting: they helped popularize the idea that human energy is cyclical and that self-observation of these cycles has value. This idea, once freed from the erroneous mechanism of fixed sinusoids, is today at the core of chronobiology, sleep medicine, and personal-data-based wellness approaches.
Connection with Shinkofa
Shinkofa respects the history of biorhythms for what it reveals: a deep human need to understand and navigate one's energy cycles. The platform does not offer biorhythm calculations, but provides something more valuable: tools for observing and understanding your real cycles, based on your personal data and holistic profile.
The intuition of Fliess, Swoboda, and Teltscher deserved better science. Shinkofa strives to contribute to that.