Twisting the Facts: The Dangers of Confirmation Bias

Sherlock Holmes warned that “it is a capital mistake to theorize before one has data … one begins to twist facts to suit theories, instead of theories to suit facts”. That tendency to interpret information to support a pet theory or to support what we think we know is called “confirmation bias”, and it can be a major problem in police investigations when likely suspects are ignored and data or evidence is misinterpreted or even suppressed. Aviva Jeruchim, a criminal defense attorney, explains how confirmation bias works, why it happens, and how it can lead to wrongful arrests and convictions.