What else?

In the last post I talked about my friend who prescribed the wrong medication for himself. He has enough knowledge to KNOW that antibiotics are not effective for common cold (and they can be even harmful) but he ACTS otherwise. Where does this knowledge-action discrepancy come from? Is there not enough evidence out there to guide us through making rational decisions? If external evidence should support rational actions, why do we act so irrationally most of the time? It is sometimes possible that right decisions are made via irrational decision making processes (voting for someone because you like her glasses and IT HAPPENS to be the best candidate). This is especially true in more complicated decisions that the results, and even the decision making processes are not readily assessable. But these are just exceptional situations and in the long run, accumulating evidence from our own life should support the rational decision making not the opposite.

 

I don’t want to address all these issues here; irrationality is a multifaceted issue and talking about all different aspects of it is far beyond my knowledge and the scope of this blog. What I’m interested in is explaining human irrationality using the concepts of “cognitive biases” and also “logical fallacies”. Since I mentioned cognitive biases before, in this post I only talk about logical fallacies. Logical fallacies are flawed patterns of reasoning by using which the false conclusion follows the true premises. Here is an example:

 

If A is correct, then B is correct

B is correct

Therefore A is correct

 

One logical fallacy which is related to my friend’s example is something called “regression bias”. In this fallacy, the person makes predictions that “expect exceptional results to continue as if they were average”. Let’s get back to our example to see what exactly this means. Common cold is a self-limited disease that takes 3-5 days if uncomplicated. After 2-3 days the symptoms get worse and this is the point that most people try to do something for it (random antibiotics, etc.). They wrongly assume their current condition as average, and believe that if they get better there must be a cause and that cause must be whatever they did (e.g. taking antibiotics) to feel better. These diagrams show how I see this problem:

 

Rational: The person’s average, normal condition (being healthy) –> Virus (CAUSE) –> Getting cold –> No virus – happens naturally in the course of the disease – (REMOVING THE CAUSE) –> Getting better

 

Irrational: Having cold (WRONGLY ASSUMED TO BE THE AVERAGE CONDITION) –> Antibiotics (CAUSE) –> Getting better

 

Because the person gets better soon after taking antibiotics (which would happen even if she didn’t take them), this behavior (taking antibiotics whenever you have a BAD COLD) is reinforced and continues in the similar situations.

Note: this post is written based on my personal unsupported speculation and has nothing to do with my background in medicine.

 

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FARZAD said:

“hi dear.wazzup? i’m not good at thinking scientifically! but i think u were talkin bout a case of wishful thinking that sth happens coz u just think n expect it to happen.is that right or i got it wrong?! u know a lot of superstitions come to exist just that way!a cow licks ppl n they r healed! just the coincidences that r interpreted as the cause!”

HERE IS SOME MORE EXPLANATION:

You are right, one of the most common mistakes that we do is to assume that every correlation implies causation.

“Regression fallacy” in this context could be a special form of causation fallacy (which is also called Post hoc ergo propter hoc). Let me first remind you of what Regression itself is. Regression in statistics is : if you just look at the extremes of one spectrum (e.g in “people’s height”, just looking at the tallest or the shortest people) and measure the correlation of that factor with another variable (the “heights of their children”), you see the regression towards the mean (average); meaning that the children’s height is closer to average than their parents. It is true that height of parents is positively correlated with heights of their children. BUT if you just look at the VERY high or VERY short parents, their children are not THAT tall, or THAT short, but they are still tall or short but closer to the average height that what you expect.

Regression fallacy is when you ASSUME special occasions to be the AVERAGE condition. In the example that I had (having antibiotics for a simple viral common cold), your average state is when you are healthy. In other words having cold or being ill is and extreme condition in the context of your general well-being (most of the time you are healthy; just occasionally you get sick). So there is a high chance that you get back to your normal healthy state without doing anything (unless you get a really bad disease that will kill or disable you with no treatment; we are not talking about this now). One type of logical error that people may commit is that they THINK that their current state (being ill) is their average; and it does not change unless they do something for it. Someone gets medications, someone go to the homeopath, magician, or whatever. While doing this, the disease takes it course and the person get better (getting back to the ACTUAL average). Then he wrongfully thinks that the medication made him better, and the vicious cycle (false belief –> wrong action –> false belief –> …) continues.