Dr David McGrath

Spine Physician

MB BS (Hons) FAFOM, RACP, FAFMM
Master of Pain Medicine

Superstitions and Wrong Beliefs

Superstitious beliefs are common and we are all prone to their seduction. It is interesting to analize the mathematics.

ExplanationTruth	Yes	No
Accept	a	b
Don't Accept	c	d

The situation is summarised in the contingency table above.
Cell "a" is accepting an explanation which is true.
Cell "b" is accepting an explanation which is false.
Cell "c" is not accepting an explanation which is true.
Cell "d" is not accepting an explanation which is false.

A superstitious belief is one where a/b is a very low number. Why do we hold such ideas?

I suspect that believing in low odds explanations come from our past evolution.
The jungle example will suffice. In the jungle we would need to distinguish between innocuous sounds and those of a predator (to us). If we explain a noise as "tiger" and make appropriate action nothing bad occurs. If most of the noises are not tigers then we have taken actions which are mostly superfluous but nonetheless "safe".
Lets put in some numbers.

ExplanationTruth	Yes, Tiger present	No, Tiger absent
Accept, Tiger Present	1	99
Don't Accept, Tiger Present	1	99

In this case, avoidence activity occurs 100 times, 99 of which are unecessary. Noises are ignored as innocuous 100 times, but on one occasion there is a real threat. When the tiger is present, there is a 50% chance of avoidence behavior. (compared to no avoidence).The price for the improved survival odds is the need to take 99 actions which were not necessary.
In other words,"It pays to be wrong". Or in yet another expression, "Better safe than sorry".
In addition, the action tend to reinforce the conviction that a tiger has been avoided 100 times.In other words,my actions have "validated" my belief structure about the prescence of a tiger.

There is a similar situation with superstitious beliefs. Generally the holder of the belief pays a small price (99 redundant actions) to avoid the low odds chance of a significant negative event. Superstitious beliefs are abundant in medicine and religion and politics. They are an insurance policy against the possibility of hell,poor health and physical threat.

They are also cheap to own, but there may be an oportunuity cost or worse. A person seeking a cure for a poorly understood condition will be vulnerable to try a number of remedies each with a poor liklihood of success. In this case the "price" is time and money. The "opportunity cost" maybe the a distraction away from a much better odds treatment.

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