search

Become an active member of our fallacy-discussing community (or just become a lurker!)

Regression Fallacy

(also known as: regressive fallacy)

Description: Ascribing a cause where none exists in situations where natural fluctuations exist while failing to account for these natural fluctuations.

Logical Form:

B occurred after A (although B naturally fluctuates).

Therefore, A caused B.

Example #1:

I had a real bad headache, then saw my doctor.  Just by talking with him, my headache started to subside, and I was all better the next day.  It was well worth the $200 visit fee.

Explanation: Headaches are a part of life, and naturally come and go on their own with varying degrees of pain. They regress to the mean on their own, the “mean” being a normal state of no pain, with or without medical or chemical intervention. Had the person seen a gynecologist instead, the headache would have still subsided, and it would have been a much more interesting visit—especially if he were a man.

Example #2:

After surgery, my wife was not doing too well -- she was in a lot of pain.  I bought these magnetic wristbands that align with the body's natural vibrations to reduce the pain, and sure enough, a few days later the pain subsided!  Thank you magic wristbands!

Explanation: It is normal to be in pain after any significant surgery.  It is also normal for the pain to subside as the body heals -- this is the body regressing to the mean.  Assuming the magic wristbands caused the pain relief and ignoring the regression back to the mean, is fallacious.

Exception: Of course, if the “cause” is explained as the natural regression to the mean, then in a way it is not fallacious.

My headache went away because that’s what headaches eventually do -- they are a temporary disruption in the normal function of a brain.

Fun Fact: Seeing a doctor can have a real effect on pain relief, even if the doctor does nothing but provide a sympathetic ear. This is known as the psychosocial context of the therapeutic intervention and is often considered part of the placebo effect.

References:

Poulton, E. C. (1994). Behavioral Decision Theory: A New Approach. Cambridge University Press.

Questions about this fallacy? Ask our community!

Grow Intellectually by Taking Dr. Bo's Online Courses

Dr. Bo is creating online courses in the area of critical thinking, reason, science, psychology, philosophy, and well-being. These courses are self-paced and presented in small, easy-to-digest nuggets of information. Use the code FALLACYFRIENDS to get 25% off any or all of Dr. Bo's courses.

View All Dr. Bo's Courses