Thursday, November 14, 2013

Biological Rhythms and Biorhythms: Science vs Pseudoscience

"Biorhythm" cycles
We all have good days and bad days.  Sometimes it's random chance, sometimes it's our own fault, and sometimes somebody else is to blame. Throughout history, people have tried to explain or predict good and bad days through various methods.  People have used astrology, tarot cards and tea leaves to try to tell fortunes or predict events. 

Another way, called biorhythms, was popular in the 60s, 70s, and 80s.  The biorhythms idea says that various aspects and events (births, deaths, etc.) in a person's life follow cycles based on mathematical equations.  While there's no scientific evidence that biorhythms can predict anything any better than flipping a coin, many people believed in it and some still do believe in it.

The theory of biorhythms is an example of pseudoscience.  Pseudoscience literally means "false science," and that's an apt description.   Pseudoscience is often characterized by exaggerated claims, like being able to predict the timing of events far in the future.  Pseudoscience also contains a small grain of real science to try to make it look legitimate.  The biorhythms idea takes advantage of the fact that there are real biological cycles.    

Looking at the idea of biorhythms can teach us quite a bit about how to distinguish science from pseudoscience, which is very important in our society today where anyone can get on the internet and try to sell any crazy idea they want to.  Let's talk about the theory of biorhythms, real biological cycles, and some ways to tell pseudoscience vs. science after the jump.


Coin-operated biorhythm machine (from Wikimedia Commons)
The concept of biorhythms was most popular in the 1960s, 70s, and even into the 80s, but it goes back much further.  The idea of certain days being "lucky" is a common theme in  folklore.  However, it was Wilhelm Fliess, a physician and friend of Sigmund Freud, who was the first "scientific" proponent of the biorhythm idea in the 19th century.  Fliess had a lot of kooky ideas in addition to biorhythms, including how pressure points on your nose affected sexual function, but that's a topic for another post.

Basically, Fliess believed that there were certain cycles and events in our lives that occurred at either 23 or 28 day intervals.  The idea was later picked up on (or independently "discovered," depending on whose account you believe), in 1904 by a psychology professor named Hermann Swoboda.  Another professor, Alfred Teitscher, was another major proponent of this idea as he believed that his students' academic successes followed a 33 day cycle.  

The first serous academic book on biorhythms was written in 1923 by Nikolai Parna, titled Rhythm, Life, and Creation.  For the next few decades, biorhythms lingered on as a weird idea that people would try to correlate with everything from births and deaths to illness and job success.   

In the 1960s and 70s, an increased interest in mysticism and pseudosciences like astrology also led to a larger interest in biorhythms.  There was a popular series of books published on biorhythms by Bernard Gittelson, who also made a lot of money through a company that sold biorhythm charts and calculators.  Some people took it seriously while others took it as a game.  Regardless, lots of biorhythm products were sold and lots of money was made.  There's a great page on the Kosmos 1 "biorhythm calculator" (ca. 1977) here that illustrates what many of the biorhythm products looked like and what they promised. 

People were investigating biorhythms as a potentially real effect up until the 1980s and were publishing results in real scientific journals, too.  However, the overwhelming majority of these studies proved the theory was useless to predict anything.  In 1998, a meta-analysis (a re-analyzation of previous studies) reviewed 134 prior published studies on biorhythms.  This analysis revealed that at least 99 of these studies concluded that the biorhythm hypothesis was not valid, and the 35 remaining studies that in some way support the biorhythm hypothesis suffered from "methodological and statistical errors that account for the claimed findings supporting the theory."  Basically, this study concluded that biorhythms are no better than random chance at predicting anything.

However, some people still believe in biorhythms today, and you can go online and find many websites that will calculate your biorhythms charts.  Just google "biorhythm" and you'll find a lot of them.  
  
The most popular "biorhythm" equations; t is number of days since birth
In most versions of the biorhythm theory, there are three main "cycles."  A physical cycle controls health and well being.  An emotional cycle controls mood, creativity, and sensitivity.  An intellectual cycle controls reasoning, memory, and communication.

One of the red flags about biorhythms is that that the choice of cycles appears completely arbitrary.  Many biorhythms calculators use a 23 day physical cycle, a 28 day emotional cycle, and a 33 day intellectual cycle.  The 28 day cycle is probably used because of the menstruation cycle, but why not use a 24 or 25 day cycle?  Why does everybody have to have the same cycles?  Why don't people vary?  There's never any reasoning presented to answer these questions.  Real scientific theories are almost never that arbitrary.

Importantly, the cycles run on different frequencies, so one cycle can be "high" while others are "low," resulting in blurry combinations of highs and lows that can complicate interpretation.  There's almost never an absolute "high" or "low."  Days that are in the middle of the cycle (crossing the x-axis in the graph) are often noted as "critical days" that are "increased times of uncertainty."  You can start to see that a biorhythm chart will give a lot of complicated and ambiguous interpretations.  This results in little to no predictive value, but makes it easy to falsely correlate events with cycles in hindsight.   Basically, if you want to believe that something is there, this theory is ambiguous enough that you can see whatever you want to see if you look hard enough.  This is particularly true if you focus on correlating positive examples while ignoring the negative data (ie, the life events that don't line up with the curves they way you would expect).

Pseudo-scientific ideas are often characterized by a refusal of proponents to accept disproving evidence.  In the case of biorhythms, proponents may focus on one or two examples where an event did correlate with a biorhythm cycle while ignoring many cases where events did not correlate.  In real science, examples or observations that disprove a theory or hypothesis make the whole idea or parts of the idea invalid or at least in need of major revision.  When you see people propose a scientific theory and focus too much on positive data supporting it while ignoring negative data refuting it, you can make a pretty good guess that they are peddling pseudoscience.

The idea of biorhythms also illustrates one more common feature of pseudoscience.  It has just enough of a glimmer of science behind it to make some people think that there might be some legitimacy to it.  After all, we do have biological cycles, including a 24-hour sleep/wake cycle and 28-day hormonal cycles that control menstruation in women.  Pseudosciences like biorhythms often subvert people's better judgment by invoking just enough real science to make them seem legitimate.  Often, the tiny hint of fact within is enough to make some people scratch their head and think, "There could be something to that...."

These biological rhythms are very important to the functioning of our bodies.  The most well known biological cycles are circadian rhythms, which are based on the 24 hour day.  Our sleep/wake cycle is the prime example of this.  The name circadian comes from the latin circa diem, which means around one day or approximately one day.  Other biological cycles that occur on shorter frequency than 24 hours are called ultradian rhythms.  Examples of ultradian rhythms include blinking, changes in blood pressure, and heart beat.  Urination and appetite are also ultradian rhythms.  Biological cycles that occurs on a longer time scale than 24 hrs are termed infradian rhythms.  The main example of an infradian rhythm is the approximately 28-day menstrual cycle in women.              

Circadian rhythms are particularly interesting because the disruption of circadian rhythms has been been linked to many human disease, including cancer, depression, memory issues, and metabolic diseases.

Image is from the NIH/NIGMS
We know that the major regulator of the circadian clock in humans is in a cluster of about 20,000 nerves called the suprachiasmatic nucleus or SCN, which is located within the hypothalamus region of the brain, but other tissues in the body may also have clusters of nerves that play a role in circadian cycles.  There's also even some newer evidence that endocannabinoid signaling (discussed in a previous post) may also play some role in some circadian rhythms. 

The biological control of circadian rhythms is complicated and is currently a very active area of biology research.  It is influenced by genetic factors as well as environmental factors, including light exposure.  This is the major reason that people are encouraged to reduce their exposure to light from TVs or computers right before bedtime.  Your body needs darkness to help it know that it is time to go to sleep.  When the optic nerves from your eyes signal to the brain that it is dark, the SCN in the brain responds by activating production of melatonin, a hormone that promotes sleep.  Light makes the SCN repress melatonin production and stimulates production of cortisol, another hormone which helps to keep you awake.           

The real biological rhythms that exist are what helps to bring the biorhythm theory from the realm of magic into the realm of pseudoscience.  It helps the biorhythm theory pretend to be real science. 

Distinguishing pseudoscience from science is an important skill in today's society, particularly when anyone can post anything they want online and try to make themselves seem like an expert.  Pseudoscientific theories often focus on outrageous claims that may have an arbitrary basis, may completely ignore negative data, and may invoke a small glimmer of real science to make them seem more valid.  If someone promises they can use science to do something that's too good to be true, like predicting your future, you are probably looking at pseudoscience.     
   
Text © 2013, The Mad Science Blog. 

Further Reading on Circadian Rhythms:
  • National Institutes of Health National Institute of General Medical Sciences.  "Circadian Rhythms Fact Sheet."  Available here.
  • J.A. Mohawk, C.B. Green, and J.S. Takahashi.  "Central and Peripheral Circadian Clocks in Mammals."  Annu. Rev. Neurosci. 2012. 35:445-462 Available here.
  • I. Kwon, H.K. Choe, G.H. Son, and K. Kim.  "Mammalian Molecular Clocks."  Exp. Neurobiol.  2011. 20:18-28.  Available here.
  • M.H. Vitaterna, J.S. Takahashi, and F.W. Turek.  "Overview of Circadian Rhythms."  NIH/National Institute on Alcohol Abuse and Alcoholism.  Available here.
  • W. Huang, K.M. Ramsey, B. Marcheva, and J. Bass.  "Circadian Rhythms, Sleep, and Metabolism."  J. Clin. Invest.  2011.  121:2133-2141.  Available here.
  • A.A. Kondratova and R.V. Kondratov.  "Circadian Clock and Pathology of the Ageing Brain."  Nature Reviews in Neuroscience.  2012.  13:325-335.  Available here.
Other Sources:
  • V.J. D'Andrea, D.R. Black, and N.G. Strayrook.  "Relation of the Fliess-Swoboda Biorhythm Theory to Suicide Occurrence."  Journal of Nervous and Mental Diseases.  1984.  172:490-494.
  • T.L Dezelsky and J.V. Toohey.  "Biorhythms and the Prediction of Suicide Behavior."  Journal of School Health.  1978. 48:399-403.  
  • M. Feinleib and R. Fabsitz.  "Do Biorhythms Influence Day of Death?"  New England Journal of Medicine.  1978.  298:1153.  
  • B.P. Hasler, L.J. Smith, J.C. Cousins, and R.R. Bootzin.  "Circadian Rhythms, Sleep, and Substance Abuse."  Sleep Med Rev. 2012.  16:67-81.  Available here.
  • A. Hida, S. Kitamura, and K. Mishima.  "Pathophysiology and Pathogenesis of Circadian Rhythm Sleep Disorders."  J Physiol. Anthropol.  2012.  31:7.  Available here.  
  • T.M. Hines.  "Comprehensive Review of Biorhythm Theory."  Psychol. Rep.  1998. 83:19-64.
  • M.-D. Li, C.-M. Li, and Z. Wang.  "The Role of Circadian Clocks in Metabolic in Metabolic Disease."  Yale J. Biol. Med.  2012.  85:387-401.  Available here.
  • C.K. Mulder, M.P. Gerkema, and E.A. Van der Zee.  "Circadian Clocks and Memory: Time-Place Learning."  Front Mol Neurosci.  2013.  6:8.  Available here.
  • B.M. Quigley.  "'Biorhythms' and Men's Track and Field World Records."  Medicine and Science in Sports and Exercise. 1982.  14:303-307. 
  • S. Rana and S. Mahmood.  "Circadian Rhythm and Its Role in Malignancy."  J. Circadian Rhythms.  2010.  8:3.  Available here.
  • T. Reilly, K. Young, R. Seddon.  "Investigation of Biorhythms in Female Athletic Performance."  Applied Ergonomics. 1983. 14:215-217.   
  • S. Sahar and P. Sassone-Corsi.  "Regulation of Metabolism: The Circadian Clock Dictates the Time.  Trends Endocrinol Metab.  2012.  23:1-8.  Available here
  • R. Salgado-Delgado, A. T. Osorio, N. Saderi, and C. Escobar.  "Disruption of Circadian Rhythms: A Crucial Factor in the Etiology of Depression." Depress Res Treat. 2011.  2011:839743.  Available here.
  • C. Savvidis and M. Koutsilieris.  "Circadian Rhythm Disruption in Cancer Biology."  Mol Medicine.  2012.  18:1249-1260.  Available here.
  • J.W. Shaffer, C.W. Schmidt, H.I. Zlotowitz, and R.S. Fisher.  "Biorhythms and Highway Crashes.  Are They Related?"  Archives of General Psychiatry.  1978.  35:41-6. 
  • A. Shostak, J. Husse, and H. Oster.  "Circadian Regulation of Adipose Function."  Adipocyte.  2013.  2:201-206.  Available here.  
  • L.K. Vaughn, G. Denning, K.L. Stuhr, H. deWit, M.N. Hill, and C.J. Hillard.  "Endocannabinoid Signalling: Has It Got Rhythm?"  Br. J. Pharmacol. 160:530-543.  Available here.
  • D.K. Winstead, B.D. Schwartz, and W.E. Bertrand.  "Biorhythms: fact or superstition?"  American Journal of Psychiatry. 1981. 138:1188-1192.
  • D.K. Winstead, B.D. Schwartz, D. Mallott, and W.E. Bertrand.  "Biorhythms Revisited: Rhythm and Blues?"  Journal of Clinical Psychiatry.  1984.  45:426-429.
  • L. Zhu and P.C. Zee.  "Circadian Rhythm Sleep Disorders."  Neuro Clin.  2012.  30:1167-1191.  Available here.

3 comments:

  1. very well written.First time i heard this term biorhythms.Had thought it must be some kind of circadian rhythm,but turns out this is different.If biorhythm was indeed biological and scientifically viable in this context, it must have a nuerological ,hormonal or genetic origin,like circadian rhythm does!But that doesnt seem the case.I think the way biorhythm seems to be peddled about as a subset of normal circadian rhythm theory many people will be mistakenly assuming the former to be part of later.This makes the problem convoluted.I also find it hard to believe that it must be conserved across humans,with almost no variation.Only few biological phenomenon are unchanging across humanity..ex DNA.Thus strong reasons to be highly skeptical of this biorhythm concept

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  2. It created WWI and WWII and resides subconsciously in people primarily women who create it's predicted outcome. It's entirely bogus without any logic on how any of if could be based on a birthday. Created by two crooks that needed to make something of themselves working for Freud. It got the world off track, with nothing else to go by. They were from Austria and Germany. At first I thought maybe check women's biorhythms/relationship comparisons to understand if on it, effected by it. But now it's destroy the concept... present it as bogus ... warn people... they are under it's spell... it's a scourge that needs to be told.

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