Confirmation Bias

Hallo skeptics,

Today I am going to be blogging about one of the most commonly used logical fallacies out there, confirmation bias. It is used in a range of topics including alternative medicine, religion, UFOlogy, astrology, psychics, mediums, and almost all topics which skeptics keep tabs on. Confirmation bias is a logical fallacy which is often referred to as cherry-picking, however is slightly different. While similar, cherry-picking refers to picking single studies from a sea of negative papers, confirmation bias is the picking out of specific results, not specific studies.

One of the most simple and common uses of confirmation bias is praying. I recently saw one of those Facebook like-hoarding pictures which asks for likes to confirm ones religious views, which read “Like this photo and in the next 120 seconds god will do you a favour”… it had over 30 000 likes. I read that and immediately saw it as a perfect example of confirmation bias. To anybody who likes that status, I can almost guarantee that something good will happen to them in the next 120 seconds. The reason is that people want it to come true. If something slightly good happens to that person in the next 120 seconds, they will attribute that to liking the photo… your basketball team makes a buzzer-beating game winner? God did that. Mum decides to give you a little extra ice-cream for dessert? god did that. Get a new twitter follower? god did that. Whatever happens, god is the reason.

It doesn’t even have to be within 2 minutes, you will remember anything that happens for the whole rest of the day and give credit to god… because a thousand years is like a day and a day is like a thousand years, or some post hoc reasoning like that. Even if nothing good happens, that means the devil was going to do something bad to you but god saved you because you liked the photo.

This photo is a perfect example of how confirmation bias works. Another common example is in alternative medicine. Lets say somebody gets cancer, and they decide to, along with their doctor approved, scientific medicine, have a chiropractor try to fix it. Once the cancer has been removed, the patient might only remember the chiropractic treatment that cured the cancer, and forget all the scientific medicine that actually removed the cancer.

Confirmation bias is one of the most common fallacies out, and is often combined with other fallacies like post hoc ergo proctor hoc, placebo, reliance on memory and the availability heuristic to form the greatest of all fallacies, the anecdotal evidence.


Post Hoc Ergo Propter Hoc


Due to all the political ‘hoopla’ going on in the great state of Queensland at this time, because of the upcoming election in a few days time, I have been hearing a lot of political arguing. I have been pretty happy with the quality and the logic behind the arguments, but the Labor party (who is almost guaranteed to lose to the LNP this year) has been resorting to Post Hoc arguments and Ad hominem  attacks in the up-hill battle to hold on to seats. Today I will not be blogging about these arguments, but I think now would be a good time to introduce you all to these two logical fallacies. Today’s blog will be about Post Hoc Ergo Proper Hoc.

Post Hoc Ergo Proper Hoc is a common logical fallacy which often seems to hold weight at first sight and also seems logical in basis, but is not. Post Hoc Ergo Propter Hoc is latin for ‘after this, therefore because of this.’ You will see this argument everywhere, all the time, and for simple things, is logically valid. For example, to say that putting one’s hand on the hot stove will burn one’s hand. That is correct logic, but this argument breaks down when you try to apply it to even slightest of complex problems.

The most common use of this argument is in testimonials for alternative medicines and day-time television commercials for acne removal cream or the ab-circle pro. It is a perfect demonstration of this argument, and its flaws. If one has a sore back, and decides to go to the Chiropractor to fix it. The Chiropractor gives the patient some herbal remedies and a nice massage and manipulates his neck, and a few weeks later, the patients back feels much better. He tells all his friends about how the Chiropractor fixed his back, and all his friends go to the Chiropractor to get their sore back fixed.

This attribution to the Chiropractor is very illogical. There are a whole plethora of reasons why the patients back could have got better, other than the Chiropractor. The patients back may have gotten better any way, because it is a very arbitrary and subjective thing, back pain. He could have been the beneficiary of some pain-killers, or he might have been doing some home treatment like hot-packs and stretches, and that may have fixed up his back. It is unfair for the Chiropractor to get the credit.

It also is a common proof for some people that prayer works. If you pray for your friend Steve to make a speedy recovery from his Influenza, and he does recover, then you may attribute that to the fact that you prayed for it. Never mind the fact that everybody gets over the flu eventually.

I will leave you with a quote from an unknown author, “Correlation does not equal causation.” Anonymous, a Joe Klein, a 13th century English student and a New York Quartet group of some note.