Confirmation Bias: What is it, why is it important, and what can we do about it?
Confirmation bias is sometimes defined as the tendency we can have to look at evidence that supports what we already believe as valuable and important and not looking for, or discounting evidence that does not support what we already believe. So what we get out of evidence is not a clear picture of the facts, but a confirmation of what we already believe.
Confirmation bias is the most common form of a whole class of perception fallacies that fall into a category called “Selective Attention”. Anyone who has kids, or ever was a kid, or is, or was married or in a relationship, has experienced at least a little “selective attention”. While we all know what this is about to some degree, what we may not be familiar with is just how destructive it can be. Which brings us to this—-
What if you had to navigate treacherous waters in a ship without a rudder? How about without vision, and without a lifeboat? Without clear vision, we do not have a foundation to make wise effective choices. We are, in effect, doomed to be carried wherever the winds and currents take us. If our ability to navigate is infected with confirmation bias, or any logical fallacy for that matter, the chances increase that we will be unwitting participants in our own poverty, suffering and perhaps even destruction. Even more than this, because we are social creatures, we could get “splash damage” from others who are infected with confirmation bias. Confirmation bias can be infectious. At least one, if not both of the space shuttle disasters were caused in part by underestimating what was at the time the importance of known evidence. The pressure to launch and other factors led to discounting critical evidence which led to the death of the crews. So understanding logical fallacies is important – but even more important than understanding is developing the skill to apply this information to our thoughts and lives in general.
One historic example of the destructive nature of confirmation bias can be seen in the work of Aelius Galenus (Galen), He is a prime example of how destructive a confirmation bias can be, even if the bias is mixed in with solid empirical evidence.
Around the end of the 2nd century CE Galen built on the concepts adopted and systematized by the Hippocratic School of Medicine centuries earlier. Most of us probably know Hippocrates. He is sometimes called the father of western medicine.
Galen used exceptional scientific research methods for his time. Among the things he did was to dissect and perform vivisections on animals to examine the way the biological structures worked. His experimental approach involved examining the nature of biological systems in order to reveal their function and purpose. Galen’s research was built on the idea that the organs and various fluids and so on in biological systems had a purpose which he sought to discover. He also believed that the balance of humors were a foundational key to understanding biological systems.
The theory of humors is the idea that the balance of four fluids in the body, black bile, yellow bile, phlegm and blood need to be balanced, otherwise the body gets sick. The theory of humors was widely accepted as fact in Galen’s time. Since he adopted this longstanding belief, it powerfully influenced how he saw and interpreted the workings of biological systems. The treatments and practices that came from his work were colored by the underlying assumption that the balance of humors determined health and sickness. This is the heart of confirmation bias. It had the effect of greatly reducing the ability of his work to result in accurate understanding. It also stalled the development of effective medical diagnostics and treatments as we will see.
Galen wrote a lot! He was also a self-assured, flamboyant, charismatic and controversial figure in his time. He documented and very publically promoted what he thought. He also actively discounted and put down any views that were counter to his own. As a result of his work and personality, he greatly influenced the way medicine was viewed and practiced. Over time his work was considered so accurate and complete that it reduced the perceived need for additional investigative research. He became the primary authority on western style medicine in many places. The dominance of his influence in terms of understanding anatomy, diagnostics and practical medicine lasted well into the 16th century.
Although he used a scientific approach to medicine, he also held the assumption that humors were the primary source of disease. When this was coupled with the high esteem in which his findings were held, he had the net effect of crippling significant medical advances for well over 1500 years! His confirmation bias led to generation after generation of more confirmation bias. Research on anatomy and physiology as well as pathology virtually stopped because almost everyone believed that he had figured it all out. Because of this, health practitioners were not prepared to deal effectively with common diseases, much less plagues and other serious ailments. Medical practices like bloodletting (used to bring balance back to the bodily humors) persisted throughout the period with limited and often destructive consequences. If we were to tally the actual suffering and death that came from this one assumption in the history of western medicine, we can begin to understand how the power of an idea, adopted as truth, can shape everything else we see and do. We can also see how accepting untrue assumptions can have disastrous effects especially when tradition, perceived authority and undeserved value is placed on ideas instead of facts.
While this brief history of humors in medicine is one example of how confirmation bias can affect vision and actions destructively, the same principles can be at work in our individual minds as well as our larger culture. One of the ways medical science combats logical fallacies in research today is to test using a double blind procedure. This is where two groups are set up to test a treatment or drug. One group gets the treatment and one group gets a placebo (like a sugar pill) or a fake treatment. This way the results can be trusted without such things as confirmation bias affecting the results.
Well, that’s confirmation bias for you.
Here are some questions to explore it a little deeper:
1. Even though he used empirical evidence, do you think Galen’s vision was distorted by the popular and well established ideas of his time?
2. Do you think he was sincere in his view? (Follow up questionà) What do you think that says about sincerity and accuracy? (Follow up questionà) How do you think that relates to our individual lives? Do you think we might have some poison in our ability to see clearly? Where do you think we may have picked up some of these destructive assumptions?
3. Do you think there are some ideas we might hold today as a culture that have the same destructive impact? (Follow up questionà) Do you think we might not be aware of biases because of their popularity? (Follow up questionà) How about other reasons that are not based on popularity? What else can lead to confirmation bias? Childhood trust of parents? Authority figures? Advertisers?
4. If we are not good at spotting confirmation bias in our thinking, what do you think the consequences are for ourselves? Our Culture? Our globe?
5. Can you think of an example from your own life where confirmation bias was harmful or destroyed a relationship, someone’s growth etc.?
6. What do you think the best way to combat this in our own lives is?
How about the lives of those we want to influence positively to be better equipped to navigate life effectively?
I hope this was helpful. Thanks in advance for the comments.