Related Terminology & Plausibility

Biorhythmics is either a protoscientific branch or a pseudoscience, depending on opinion, that studies biorhythms or deal with biorhythms. Biorhythmic study focuses on physiological, emotional, and intellectual processes and its forecasting. Biorhythm phenomena are observable human conditions which can be detailed and explained by biorhythmics. These conditions are bound by the variables that exist in the body. Certain facets of biorhythmics are likened by proponents to concepts found in weather forecasting (commonly known as meteorology).

Chronobiology is a branch of biology that studies rhythms in living beings. Unlike biorhythm, its status as a science is unquestioned.

Proponents of biorhythmics call it an established interdisciplinary area of scientific endeavor which is still speculative - a protoscience. Critics state that biorhythms are based only upon numerological associations. The plausibility of biorhythmics is contested by mathematicians, biologists and other scientists. The most basic assertion is that, even if physiological rhythms do exist, why would they begin precisely on the day of our birth?

Biorhythmics has echoes of chronobiology, the study of biological rhythms. Through medical research, doctors have found that there are periodic biological cycles in a person's lifespan, such as the circadian rhythm (from Latin circa diem; literally, "about a day"), but few doctors believe they correspond to those described as "biorhythms". To proponents, these discoveries (among others) demonstrate that people are affected by physiological, emotional and intellectual rhythms, though the exact relationships to the biorhythm cycles are not precisely understood. Studies regarding the effects of biorhythms on the human condition are still conducted.

The Biorhythm theory is often treated as falsely claiming scientific validity. Biorhythm critics' responses range from opposing it as harmful to ignoring it or treating it as entertainment. Some of the criticisms of the various theories in the category of biorhythmics are:

• The choices of periodical function, frequency and phase are arbitrary.
• The assumption is made that the cycles are the same for everyone.
• The frequency is assumed to be constant.
• Evidence tends to be anecdotal.
• Arguments are made based in ignorance of number theory.
• Tests of the hypothesis have basic flaws.
• The quantitative generalizations of complex human behavior are inadequate.
• Hypotheses are not formulated precisely.
• Experimental data fail peer review.
• Experiments cannot be replicated.
• Some unscrupulous practitioners resemble professional fortune-telling fraud artists.

Some biorhythm critics say that biorhythms can be thrown off by such occurrences in the calendar as the beginning of the new year, holidays, or something as simple as the start of the week.

There have been some three dozen studies supporting biorhythm theory but all of them have suffered from methodological and statistical errors. An examination of some 134 biorhythm studies found that the theory is not valid.