A quiet revolution has occurred in our understanding of the nature of bias. In the past, sociologists regarded human bias as largely conscious and intentional. No longer, today researchers have demonstrated that human biases are largely unconscious and unintentional.
This new understanding of bias has come from the field of social cognition theory which posits that from the moment that we are born, we learn to use mental categories as a form of intellectual short-hand. This improves mental efficiency but may skew human judgment. People develop unconscious positive biases around people who look like themselves, speak the same language and share the same culture. On the other hand, people develop unconscious negative biases around people who look different, speak different languages and come from different cultural backgrounds.
The Implicit Association Test (IAT) is an experimental method that suggests that many cognitive processes that affect behavior are unconscious in nature and are inaccessible to observation by the actor. These implicit processes affect perception, influence behavior, and color interpretation of past events. The IAT has been profiled in the Washington Post and the Wall Street Journal and extensively discussed in the popular book Blink. Recent academic articles have used the IAT to measure unconscious bias in medical decision-making and other areas. The method is not without its detractors and substantial commentary, both pro and con, has emerged in the fields of law, medicine and social psychology.
You can find and take the Implicit Association Test free of charge at the Project Implicit website which is sponsored by Harvard University. Simply click on the following link to take one of many popular tests purporting to measure unconscious bias on the basis of age, race, gender and other demographic categories: https://implicit.harvard.edu/implicit/demo/