Confirmation Bias

In the past few years I have taken several philosophy and critical thinking courses and read many books on the subjects. I also spend a fair amount of time reading the interaction of politics, theology and science. Time and time again I see in my reading and in my life experiences that one of the biggest critical thinking errors that people make is that of confirmation bias. That is when you accept the evidence that supports your beliefs and you disregard the evidence that contradicts your beliefs. For instance, if I believed that lottery numbers had some cosmic significance then it would confirm my belief to know that on September 11th, 2001 the winning numbers on the New York lottery was 9-1-1. But in order to accept that I need to reject the thousand of other events that do not confirm my numerologist beliefs. What were the number in Oklahoma when the federal building was bombed? How about the numbers during the first attack on the WTC? etc. etc.

To ease you minds a little I am not a numerologist. However, I have been very guilty in the past of confirmation bias. When a scientific breakthrough would prove certain dietary claims that went hand in hand with the Word of Wisdom I would accept those claims to justify my faith in the Word of Wisdom. In the process however, I would also have to reject certain other evidences like the studies that shows that a glass of wine each day can have a positive effect on your health. I enjoyed following the expeditions of Thor Hyerdal who built reed boats and sailed them from Africa to South America. They tended to support the idea that Lehi’s voyage was possible. But to accept this evidence it also meant that I had to ignore the mountain of evidence in South America that shows no link at all to the ancient middle-east.

Many scientists refer to the brain as a belief engine. It takes input from our senses and then turns that input into beliefs that will help us predict and cope with our chaotic world. When we see one event that follows another our “belief engine” makes a connection. The more often that sequence of events is seen then the more solidly that connection is made. By seeing crops grow after planting seeds and watering them you teach your brain that watering seeds causes crops to grow. The problem our brain has is that just because there is a correlation that does not mean there is necessarily a cause and effect relationship. If we continue to believe that this correlation is a cause and effect relationship we end up with weird beliefs like lucky bowling shirts and other illogical beliefs.

Looking at my own decision with a critical eye has helped me a lot. It has forced me to stop wasting effort on paths that will only lead to disappointment and it has helped me to focus on the aspects of my life that really make a difference. No longer am I wasting time trying to figure out why my lucky bowling shirt is lucky. I have just accepted that it isn’t and my game has improved. By no means am I claiming that I have eliminated confirmation bias. However, being consciously aware of why I choose to accept certain beliefs has really helped me to reach a mental peace and make sense of my surroundings.


Just for the record, the “lucky bowling shirt” is a metaphor for other events in my life. I bowl about once a month and I don’t remember which shirt I had on any of those times. I rarely bowl over 100 even with the kiddy bumpers up so I don’t think I could call any of those shirts lucky. :)