Confirmation bias is a psychological filter that causes people to interpret information in a way that proves or at least confirms what they believe is true or what they believe will happen in the future. Confirmation bias is a kind of mental bias and is the wrong way to use reason to arrive at the truth. When someone is thinking with this bias they selectively choose only the information that confirms what they already believe. When operating under this bias all information is interpreted in a way to support a preconceived belief system.
A confirmation bias is the strongest when a lot is at stake with a belief system, like money, family, religion, politics, sports, or just ego. Defense of a belief system through interpretation of new information becomes most emotionally charged when some one doesn’t want to be wrong and their ego, pride, and identity is at stake if they lose an argument or are proven wrong.
People can interpret every sign and data set by focusing only on what confirms their position and ignoring what shows they could be wrong. A person with a strong enough confirmation bias can be cognitively blind to facts that show they could be incorrect. Two people with an opposite bias can even see the same evidence supporting their different opinions due to the way they filter information. A bias can also cause people to see correlations in events and information that are random supporting their beliefs.
The danger of confirmation bias can be seen in many occupations like investing and business where the inability to clearly see new data for what it is showing in trends can lead to stubbornly losing a lot of money as opinions are set and new data showing anything different is ignored. It is an edge to know the biases you may have and be open minded to all new information that could show you are wrong and need to adjust your plan of action. The greatest minds are flexible and learn from new information.