%%bloglink%%
Confirmation bias happens when we either disregard facts that contradict our position or we fail to seek out information that would make us change our point of view.
An extreme example of confirmation bias is early testing for Huntington’s Disease.
Huntington’s Disease (HD) is a degenerative neurological disorder with no known cure that affects around 30,000 people in the U.S. Onset begins around age 40, with a life expectancy of around age 60 and a healthy life expectancy of 10 years fewer than that.
Individuals with one parent with HD have a 50% chance of inheriting the disease.
Since 1993 an inexpensive test has been available to determine with certainty if at-risk individuals will develop HD yet historically only between 5-7% of at-risk individuals opted to be tested.[1]
Researchers theorize the reason behind these extremely low testing numbers is confirmation bias. Taking the test would require individuals to seek out information that might change how they imagine their future will be.
If an individual chooses to test, they cannot “unlearn” their health status and therefore a significant “cost” of testing is the loss of the option to believe one is healthy regardless of their true state.[2]
What confirmation biases do you have?
[1] Shoulson and Young 2011
[2] Optimal Expectations and Limited Medical Testing. Oster, Shoulson and Dorsey 2013
