Biorhythm Theory: True or False? Some Results from Trials and Experiments

It is said that Marilyn Monroe and Judy Garland both overdosed on “critical” days in their biorhthym cycles. Coincidence? Or could the study of biorhythms have saved their lives?

This question–whether monitoring biorhythm cycles can actually make a difference in people’s lives–has been studied since the 1960s, when the writings of George S. Thommen popularized the idea.

Several companies began experimenting and although the Japanese were the first nation to apply biorhythms on a large scale, the Swiss were the first to see and realize the benefits of biorhythms in reducing accidents.

Planes, trains and automobiles
Hans Frueh invented the Bio-Card and Bio-Calculator, and Swiss municipal and national authorities appear to have been applying biorhythms for many years before the Japanese experiments. Swissair, which reportedly had been studying the critical days of its pilots for almost a decade previously, did not allow either a pilot or a co-pilot experiencing a critical day to fly with another experiencing the same kind of instability. Reportedly, Swissair had no accidents on those flights where biorhythm had been applied.

A differing outcome was found, however, by the Federal Aviation Administration and the U.S. National Transportation Safety Board, who examined the records of 8,625 pilots who had been involved in air mishaps. They found absolutely no correlation between negative biorhythms and the accidents.

The Zurich Municipal Transit Company bus and trollies accident rate per 10,000 kilometers had been slashed by about 50 percent within one year of the application of biorhythms. Similar positive results were reported by the municipal transit system of Hanover, Germany.

Notable trials were performed in the field of sports where, it was predicted, outstanding performances would tend to appear on days of biorhythmic highs. For example, Billie Jean King is said to have won her famous match against Bobby Riggs when at a “high” in two of her cycles.

The greatest force in the wave of biorhythms application in Japan was the work done by the traffic police and other traffic safety organizations. The Tokyo Metropolitan Police published a study in 1971 which indicated that more than 80 percent of the traffic accidents reported during the previous year had taken place on the driver’s critical day. About the same time, Osaka Police published a biorhythmic study of more than 100 traffic accidents involving child pedestrians and 70 percent of those young pedestrians had been injured on their critical days.

In some parts of Japan, everyone receiving a driver’s license for the first time or renewing a license received a personalized biorhythm chart, as did anyone involved in an accident. The result was a significant drop in the accident rate. Japanese insurance companies even helped to sponsor biorhythms-based driver safety courses and urged that every worker in Japan received a bio-curve graph in their pay envelope.

On-the-job safety
In July ’08, I spoke with a retired employee of Texaco Oil, Stephen Marsh, who was in charge of safety programs for the western U.S. oil drilling and production. In trying to inspire worker safety and to stop people getting injured on the job, Marsh saw reports about how the Japanese were using biorhythms. (The Omni Railway in Japan credited biorhythms with their accident-free record of safety. Apparently they did a two-year study where train crews wore ID badges every morning based on their personal biorhythms–green, yellow or red–and reds were given part of the day off.

The first year they were “pretty successful,” Marsh said, so he decided to experiment. He picked an area where there were the most on-the-job accidents: San Ardo, Calif. In 1976, the workforce consisted of about 120 employees all engaged in oil production, which is very dangerous work. Biorhythm charts were prepared and implemented for all employees and they were monitored very carefully for a six-month trial.

During that period, they did see a decrease to about half in first-aid cases. However, after doing an analysis, there was a contrary voice saying, “You have a yellow button on your shirt. It’s an off-day–be cautious.” Marsh suggests that the yellow-buttoned workers were pre-programmed to be more careful, and everyone around them was doing the same.

There was no placebo group in place to compare and contrast results. Although there was “satisfactory significance,” and contrary to popular media, the test went no further, for financial reasons and due to the complexity of administering and controlling the process in a large number of small operating areas.

By Brooke Rudolf, Care2 contributing writer


AledaJeanne Owen
AledaJeanne Owen1 years ago

It is September 2016. I have been checking back every month to do my biorhythm, but the CALCULATOR is no where to be found. Too bad...the Care2 calculator is the best online.

Robert B.
Robert B2 years ago

I can't find a link to the calculator either.

Monika H.
Monika H2 years ago

Can someone tell me what happened to the biorhythm calculator? I cannot find any functional link to it.

Tammy Baxter
Tammy B5 years ago

could be interesting to have a new study done and see if it really works.

Evelyn Wadsworth
Evelyn W5 years ago

I have trouble excepting this,need more study

Elaya Raja
Elaya Raja5 years ago


J.L. A.
JL A6 years ago

Amazing how much money will be spent for research into safety that points to the individual creating the risk vs. safety equipment, training and other practices (e.g., sufficient sleep for pilots in their schedules).

Natasha Lopez
Natasha L6 years ago


Victor M.
Victor M6 years ago

just a myth...

Duane B.
.6 years ago

Thank you for sharing this interesting information.